XII Iberian Meeting of Electrochemistry XVI Meeting of the ...

SPECIAL ISSUE 2010 ABSTRACTS BOOK 

XII Iberian Meeting of Electrochemistry 

XVI Meeting of the Portuguese 

Electrochemical Society

XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society 

Organizing and Scientific Committee 

Luísa Martins, Chairperson, Treasurer of SPE 

Armando Pombeiro, President of the Portuguese Society of Electrochemistry (SPE) 

Manuel Blázquez, President of the Electrochemical Group of RSEQ 

Victor Lobo, Past-‐president of SPE 

Isabel Ferra, Vice-‐president of SPE 

Alda Simões, Secretary of SPE 

Aquiles de Barros, Faculty of Sciences, University of Porto 

Enrique Brillas Coso, University of Barcelona 

Inês Fonseca, Faculty of Sciences, University of Lisbon 

João Rodrigues, University of Madeira 

José Costa Lima, Faculty of Pharmacy, University of Porto 

José Paulo Pinheiro, Faculty of Sciences and Technology, University of Algarve 

Luísa Abrantes, Faculty of Sciences, University of Lisbon 

Manuel Domínguez Pérez, University of Seville 

Manuel Matos, ISEL, Polytechnic Institute of Lisbon 

Maria de Fátima Bento, Department of Chemistry, University of Minho 

Maria Paula Robalo, ISEL, Polytechnic Institute of Lisbon 

Mário Ferreira, University of Aveiro 

Ruben Leitão, ISEL, Polytechnic Institute of Lisbon 

Vicente Montiel Leguey, University of Alicante 

Local Organizing Committee 

Bruno Rocha, 

Elisabete Alegria, ISEL, Polytechnic Institute of Lisbon 

Konstantin Luzyanin, IST, Technical University of Lisbon 

Luísa Martins, ISEL, Polytechnicl Institute of Lisbon 

Nelson Silva, ISEL, Polytechnic Institute of Lisbon 

Manuel Matos, ISEL, Polytechnic Institute of Lisbon 

Maria Paula Robalo, ISEL, Polytechnic Institute of Lisbon 

Pedro Galego, ISEL, Polytechnic Institute of Lisbon 

Ricardo Fernandes, IST, Technical University of Lisbon 

Rogério Chay, IST, Technical University of Lisbon 

Ruben Leitão, ISEL, Polytechnic Institute of Lisbon 

Telma Silva, ISEL, Polytechnic Institute of Lisbon 

September, 811, 2010. ISEL - Lisbon 

ii


Welcome Message 

Dear Colleagues, 

The Instituto Superior de Engenharia de Lisboa (ISEL) has the honor to host the 

XII IME -‐ XII Iberian Meeting of Electrochemistry and XVI Meeting of the 

Portuguese Electrochemical Society. 

Following the highly successful previous editions of Iberian Conferences, 

namely, just to mention the closest ones, those held in Tenerife (2009), 

Coimbra (2007) and La Corunha (2006), the XII IME provides, once again, a 

meeting point for scientific and technological exchange of ideas among 

delegates from academia, research institutes and industry, in all fields of 

Electrochemistry. 

The Scientific Program (as revealed by this Book of Abstracts) reflects the 

current vitality of research and diversity of Electrochemistry. 

The Organizing Committee warmly welcomes all participants, gratefully 

acknowledges their presence and wishes them a profitable and pleasant time 

along all the Conference, from both scientific and social points of view. 

All best wishes, 

Luísa Martins 

Chair of XII IME 


iii


Index 

Program ............................................................................................................................... 1 

Oral Communications List ............................................................................................. 4 

Posters List ......................................................................................................................... 7 

Plenary Lectures ............................................................................................................... 11 

Key Notes ............................................................................................................................ 17 

Oral Communications ..................................................................................................... 25 

Poster Communications ................................................................................................ 55 

Authors Index .................................................................................................................... 109 


iv


Thursday, September 9 th , 2010 

Program 

Time Ref Room C 

08:45 Opening Session 

09:00 PL1 

10:00 OE 1 

10:20 OE 2 

10:40 OE 3 

11:00 OE 4 

11:20 Coffee Break 

12:00 KN 1 

12:30 KN 2 

13:00 Lunch 

14:30 PL 2 

Electron Reservoir Activity of High-‐Nuclearity Transition Metal Carbonyl Clusters 

Piero Zanello, University of Siena, Italy 

Electrochemistry of Push-‐Pull Compounds based on Quinoline-‐N-‐Oxide 

Cristina Ferron, University of Malaga, Spain 

Electrochemical, Thermodynamic and Kinetic Studies of the Acylated Cyanoimido-‐Complexes 

trans-‐ [Mo(NCN){NCNC(O)R}(dppe)2]Cl 

Elisabete Alegria, Polytechnic Institute of Lisbon, Portugal 

Potentiometric Determination of Copper with a New Selective Electrode 

Kamran Mahmudov, Technical University of Lisbon, Portugal 

Redox Properties of Cu(I) Camphor Hydrazone Complexes 

Tiago Fernandes, Technical University of Lisbon, Portugal 

Novel Layer-‐by-‐layer Interfacial [Ni(salen)]-‐polyelectrolyte Hybrid Films 

Cristina Freire, University of Porto, Portugal 

Tratamentos de Superfície em Ligas de Alumínio de Aplicação Aeronáutica 

Mário Freitas, OGMA -‐ Indústria Aeronáutica de Portugal S.A., Portugal 

Electron Transfer in Nanostructures of Gold Substrates Modified with SAM and Gold 

Nanoparticles 

Manuel Blàzquez, University of Cordoba, Spain 

Time Ref Oral Session C - Room C Ref Oral Session B - Room A 

15:30 OC 1 

15:50 OC 2 

16:10 OC 3 


Electrosynthesis and Redox Conversion 

of Poly (3,4-‐ethilenedioxythiophene) 

Films An Ellipsometric and Probe Beam 

Deflection Study 

Ana Melato 

University of Lisbon, Portugal 

Convolutive Modelling with 

Mathematica® using Oldham-‐Mahon-‐ 

Myland Hi(t) Functions. CrEq Mechanism 

in CV 

Manuel Barrera-‐Niebla 

University of La Laguna, Spain 

Electro-‐oxidation of Alcohols on Pd-‐Ag 

Alloys in Alkaline Medium 

Cristina Oliveira 

Univ. of Trás-‐os-‐Montes, Portugal 

17:00 Young Research Prize SPE 2010 Communication 

17:30 General Assembly of SPE 

OB 1 

OB 2 

OB 3 

Application of a Membraneless 

Extraction Module in the Voltammetric 

Determination of Sulphites in Wine 

Luís M. Gonçalves 

University of Porto, Portugal 

 

Wines and its Antioxidant Activity. Gallic 

Acid Interference 

Maria José Rebelo 


An Electrochemical Biosensor for Toxic 

Amides Determination: Merits and 

Limitations 

Nelson Silva 

Polytechnic Institute of Lisbon, Portugal 

September, 811, 2010. ISEL - Lisbon 1


Friday, September 10 th , 2010 


09:00 PL 3 

Espectroscopia de Impedância Electroquímica aplicada a Estudos de Corrosão 

João Fernandes, Technical University of Lisbon, Portugal 

10:00 OA 1 

Solvay -‐ Ready for tomorrow 

Rui Rocha, Solvay Portugal, Portugal 

10:20 OA 2 

Modern QSPR Methodology to Address Non-‐solved Solution Electrochemistry Old Issues 

Luís Moreira, University of Lisbon, Portugal 

10:40 OA 3 

Investigations into the Electrochemical Synthesis of Hydrogen Peroxide 

Maria Campos, Johnson Matthey Technology Centre, United Kingdom 

11:00 OA 4 

Acidity Constants of Diprotic Acids from Potentiometric Titrations: Principles of the Calculation 

Illustrated Through the Construction of a Simple Algorithm 

Elsa Gonçalves, Polytechnic Institute of Setúbal, Portugal 


12:00 KN 3 

12:30 KN 4 

13:00 Lunch 

14:30 PL 4 

"Smart" Self-‐healing Coatings for Active Corrosion Protection 

Mikhail Zheludkevich, University of Aveiro, Portugal 

Evaluation of Antioxidant Activity: A Reagentless Electrochemical Approach 

Dulce Geraldo, University of Minho, Portugal 

Dynamic Electrochemical Studies of Redox Proteins 

Margarida Correia dos Santos, Technical University of Lisbon, Portugal 

Time Ref Oral Session C - Room C Ref Oral Session B - Room A 

15:30 OD 1 

15:50 OD 2 

16:10 OD 3 


17:00 Poster Session 

20:30 Conference Diner 

Quasi-‐simultaneous Localised 

Measurements of Current Density and 

Ion Distribution (pH, Cl -‐ , Na + ) 

Svetlana Lamaka 

Technical University of Lisbon, Portugal 

Water Uptake Estimation in Organic 

Coatings using Electrochemical 

Impedance Spectroscopy 

Raquel Duarte 


Novel Electrochemical Techniques for 

Classical Corrosion Problems: the 

Scanning Vibrating Electrode Applied to 

Galvanized Steel Cut Edges 

Alda Simões 


OB 4 

OB 5 

OB 6 

Construction of a Nitrite Biosensor based 

on the Direct Electrochemistry of a 

Multihemic Nitrite Reductase on Carbon 

Nanotube Modified Electrodes 

Célia Silveira 

New University of Lisbon, Portugal 

Polymeric Chemiresistive Sensors for 

Wood Classification 

Renata Lippi 

University of São Paulo, Brasil 

Water Soluble Phthalate Determination 

from Bottled and Coolers Water by using 

Square Wave Voltammetric(SWV) 

Technique 

Munawar Qureshi 

University of Sindh, Pakistan 



Saturday, September 11 th , 2010 


09:00 PL 5 

Electrochemistry of Molecules with Two (or More) Redox Centers 

, J. Heyrovský Institute of Physical Chemistry, Czech Republic 

Time Ref Oral Session A - Room A Ref Oral Session C - Room C 

10:00 OA 5 

10:20 OA 6 

10:40 OA 7 

11:00 OA 8 


12:00 KN 5 

12:30 KN 6 

12:50 Closing Session 

13:00 Lunch 

15:00 Excursion 

Functionalized Carbon Supported Pt-‐Ru 

Electrocatalysts for Alcohols Oxidation 

José Salgado 


Chemical Microscopy: The Study of 

Reduction-‐oxidation Reactions under a 

Stereomicroscope 

Clementina Teixeira 


The Capacitive Behaviors of Self-assembled 

Manganese Dioxide Thin 

Films 

Suh Pang 

University of Malaysia, Malaysia 

Síntesis Electroquímica Selectiva de a y/o 

b Hidroxido de Niquel con Aditivos de Co 

y su Caracterización como Material de 

Electrodo para Baterías Recargables 

Felipe Nieto 

National University of La Plata, Argentina 

OC 4 

OC 5 

OC 6 

OC 7 

Versatile Surface Functionalization of 

Gold Surfaces based on CS 2 -‐amine 

Reaction 

Inês Almeida 


Convolutive modelling with Universal 

Master Equation of Oldham-‐Mahon-‐ 

Myland by using Mathematica ® Software. 

E q C i Mechanism in CV at Spherical 

Electrodes 

Manuel Barrera-‐Niebla 

University of La Laguna, Spain 

Electrocrystallisation of (Perylene) 2 

[M(mnt) 2 ] salts 

Mónica Afonso 

Instituto Tecnológico Nuclear, Portugal 

Application of the Scanning 

Electrochemical Microscope to Study the 

Corrosion Mechanism in Thin Organic 

Coatings with Defects 

Andreia Marques 


Electrochemical Degradation of Organic Pollutants: Optimization of the Experimental 

Conditions 

Ana Lopes, University of Beira Interior, Portugal 

Assessing Performance and Degradation Mechanisms in Proton Exchange Membrane Fuel Cells 

Carmen Rangel, Laboratório Nacional de Energia e Geologia, Portugal 



Oral Communications List 

Code Title and Authors Page 

PL 1 

PL 2 

Electron Reservoir Activity of High-‐Nuclearity Transition Metal Carbonyl 

Clusters 

Piero Zanello 

Electron Transfer in Nanostructures of Gold Substrates Modified with SAM and 

Gold Nanoparticles 

M. Blàzquez, T. Pineda, R. Madueño, D. García-‐Raya 

PL 3 Espectroscopia de impedância electroquímica aplicada a estudos de corrosão 14 

João Salvador Fernandes 

PL 4 Dynamic Electrochemical Studies of Redox Proteins 15 

Margarida M. Correia dos Santos 

PL 5 Electrochemistry of molecules with two (or more) redox centers 16 

 

KN 1 Novel layer-‐by-‐layer interfacial [Ni(salen)]-‐polyelectrolyte hybrid films 18 

Cristina Freire 

KN 2 Tratamentos de Superfície em Ligas de Alumínio de Aplicação Aeronáutica 19 

Mário Freitas 

KN 3 "Smart" self-‐healing coatings for active corrosion protection" 20 

M.L. Zheludkevich, M.G.S. Ferreira 

KN 4 Evaluation of antioxidant activity: a reagentless electrochemical approach 21 

M. Dulce Geraldo, M. Fátima Bento 

KN 5 

KN 6 

Electrochemical degradation of organic pollutants: optimization of the 

experimental conditions 

Ana Lopes 

Assessing Performance and Degradation Mechanisms in Proton Exchange 

Membrane Fuel Cells 

Carmen Rangel, R.A. Silva, T.I.Paiva 

OA 1 Solvay -‐ Ready for tomorrow 26 

Rui Rocha 

OA 2 

Modern QSPR methodology to address non-‐solved solution electrochemistry 

old issues 

Luís Moreira, Marina Reis, Nelson Nunes, Rui Filipe, Filomena Martins, Ruben Elvas Leitão 

OA 3 Investigations into the electrochemical synthesis of hydrogen peroxide 28 

Maria Campos, Sarah Ball, Rob Potte 

OA 4 

Acidity Constants of Diprotic Acids from Potentiometric Titrations: Principles 

of the Calculation Illustrated Through the Construction of a Simple Algorithm 

Elsa Gonçalves, António Conceição 

12 

13 

22 

23 

27 

29 



OA 5 Functionalized carbon supported Pt-‐Ru electrocatalysts for alcohols oxidation 30 

José R.C. Salgado, Raquel G. Duarte, Laura M. Ilharco, Ana M. Botelho do Rego, M.G.S. 

Ferreira 

OA 6 

Chemical Microscopy: the study of reduction-‐oxidation reactions under a 

stereomicroscope 


OA 7 The capacitive behaviors of self-‐assembled manganese dioxide thin films 32 

Suh Cem Pang, Boon Hong Wee 

OA 8 

OB 1 

OB 2 

OB 3 

OB 4 

Síntesis Electroquímica selectiva de a y/o b Hidroxido de Niquel con aditivos de 

Co y su caracterización como material de electrodo para baterías recargables 

Felipe J. Rodríguez Nieto, Daniela Becker, Arnaldo Visinti 

Application of a Membraneless Extraction Module in the Voltammetric 

Determination of Sulphites in Wine 

Luís M. Gonçalves, Miriam F. Anunciação, Inês M. Valente, João G. Pacheco, José M. 

Rodrigues Aquiles A. Barros 

 

acid interference 

Maria J.F. Rebelo Dulce M.A. Gil 

An electrochemical biosensor for toxic amides determination: Merits and 

Limitations 

Nelson A. F. Silva, Manuel J. Matos, Amin Karmali, Maria Manuela Rocha 

Construction of a nitrite biosensor based on the direct electrochemistry of a 

multihemic nitrite reductase on carbon nanotube modified electrodes 

Célia M. Silveira, Marta Pimpão, Fernando Pereira, José J.G. Moura, M. Gabriela Almeida 

OB 5 Polymeric chemiresistive sensors for wood classification 38 

Renata Lippi, Jonas Gruber, Juliana R. Cordeiro, Erica S. Takahashi, Rosamaria W. C. Li 

OB 6 

OC 1 

OC 2 

Water soluble phthalate determination from bottled and coolers water by 

using Square Wave Voltammetric(SWV) technique 

Munawar Saeed Qureshi, Sirajuddi 

Electrosynthesis and Redox Conversion of Poly (3,4-‐ethilenedioxythiophene) 

Films An Ellipsometric and Probe Beam Deflection Study 

Ana I. Melato, J. P. Correia, L. M. Abrantes 

Convolutive modelling with Mathematica® using Oldham-‐Mahon-‐Myland hi(t) 

functions. CrEq mechanism in CV 

M. J. Barrera-‐Niebla, M.J. González Morín, M. R. García Hernández, D.M. Grandoso Medina, 

L.C. Fernández Mérida 

OC 3 Electro-‐oxidation of alcohols on Pd-‐Ag alloys in alkaline medium 42 

Cristina Oliveira Rosa Rego 

OC 4 

OC 5 

Versatile surface functionalization of gold surfaces based on CS2-‐amine 

reaction 

Inês Almeida, A. S. Viana 

Convolutive modelling with universal master equation of Oldham-‐Mahon-‐ 

Myland by using Mathematica® software. EqCi mechanism in CV at spherical 

electrodes 

M. J. Barrera-‐Niebla, M. R. García Hernández, M. J. González Morín, L.C. Fernández Mérida, 

D.M. Grandoso Medina 

31 

33 

34 

35 

36 

37 

39 

40 

41 

43 

44 



OC 6 Electrocrystallisation of (Perylene)2 [M(mnt)2] salts 45 

Mónica Afonso, Manuel J. Matos, Rafaela A. L. Silva, Quirina Ferreira, Manuel Almeida 

OC 7 

OD 1 

OD 2 

OD 3 

Application of the Scanning Electrochemical Microscope to study the corrosion 

mechanism in thin organic coatings with defects 

Andreia Marques, Alda Simões 

Quasi-‐simultaneous localised measurements of current density and ion 

distribution (pH, Cl-‐, Na+) 

Svetlana V. Lamaka, M. G. Taryba, F. Montemor, H. S. Isaacs, M. G. S. Ferreira 

Water Uptake Estimation in Organic Coatings using Electrochemical Impedance 

Spectroscopy 

R. G. Duarte, A. S. Castela, M. G. Ferreira 

Novel electrochemical techniques for classical corrosion problems: the 

Scanning Vibrating Electrode applied to galvanized steel cut edges 

Alda Simões 

OE 1 Electrochemistry of Push-‐Pull compounds based on Quinoline-‐N-‐Oxide 50 

Cristina Capel Ferron, B. Vercelli, G. Zotti, J. M. Montenegro, E. Pérez Inestrosa, V. 

Hernández, J. T. López Navarrete 

OE 2 

Electrochemical, Thermodynamic and Kinetic Studies of the Acylated 

Cyanoimido-‐Complexes trans-‐ [Mo(NCN){NCNC(O)R}(dppe)2]Cl 

Elisabete Alegria, M. Fátima C. Guedes da Silva, Maxim L. Kuznetsov, Luísa M.D.R.S. Martins, 

Armando Pombeiro 

OE 3 Potentiometric determination of copper with a new selective electrode 52 

Kamran T. Mahmudov, Maximilian N. Kopylovich, Matti Haukka, Konstantin V. Luzyanin, 

Armando Pombeiro 

OE 4 Redox Properties of Cu(I) Camphor Hydrazone Complexes 53 

Tiago. A. Fernandes, M. Fernanda N.N. Carvalho, Adelino M. Galvão 

46 

47 

48 

49 

51 



Posters List 

Code Title and Authors Page 

PA 1 

PA 2 

PA 3 

Nickel Speciation in the Xylem Sap of the Hyperaccumulator Alyssum 

serpyllifolium ssp. lusitanicum Growing on Serpentine Soils of Northeast 

Portugal 

Sheila Alves, Cristina Nabais, Maria de Lurdes Gonçalves, Margarida Correia dos Santos 

Electrodegradation of 4-‐aminonaphtalene-‐2-‐sulfonic acid with BDD and 

Ti/Pt/PbO2 Anodes 

A.S. Rodrigues, M.J. Pacheco, L. Ciríaco, A. Lopes 

Influence of hydrodynamic conditions on the anodic degradation of phenol on 

BDD 

Ana Lopes, S. Sobreira, L. Ciríaco, M.J. Pacheco 

56 

57 

58 

PA 4 Recuperação de Metais em Solução 59 

Lurdes Ciríaco, C. Ascensão, M.J. Pacheco, Ana Lopes 

PA 5 

PA 6 

PA 7 

PA 8 

PA 9 

The effects of lithium, potassium and cesium ions on the diffusion behaviour of 

caffeine in aqueous solutions 

Victor M.M. Lobo, Cecilia I.A.V. Santos, Miguel A. Esteso, Marisa C.F. Barros, Ana C.F. Ribeiro 

Improving electrocatalityc activity of LaNiO3 coatings by deposition on foam 

nickel substrates 

Cybelle O. Soares, M. D. Carvalho, M.E. Melo Jorge, A. Gomes, R.A.Silva, C.M. Rangel, M.I. da 

Silva Pereira 

Electrochemical treatment of the dye C.I. Reactive Yellow 138:1 in a filter press 

reactor 

Ana Isabel del Río, Enrique Duval, Mª José Benimeli, Javier Molina, José Bonastre, Francisco 

Cases 

Síntesis electroquímica de nanopartículas de plata y su potencial uso como 

agente antimicrobiano 

Felipe Hernández-‐Luis, Mario V. Vázquez, Lucas Blandón, Gelmy Ciro, Dora M. Benjumea 

-‐ 

suelos contaminados 

Felipe Hernández-‐Luis, Mario V. Vázquez, Lucas Blandón, Lina García, Nedher Sánchez 

PA 10 Electric Dreams 65 

Clementina Teixeira, Maria da Conceição Oliveira, Erik C.P. Benedict 

PA 11 

PB 1 

Determinación de conductividades y viscosidades del sistema (CoCl 2 + sacarosa 

+água) a temperatura de 298,15 K. 

Damien O. Costa, Ana C.F. Ribeiro, Cecilia I.A.V. Santos, Ana C. Santos, Carmen Teijeiro e 

Miguel A. Esteso 

Voltammetric Analysis of Sulphites in Alcoholic Beverages using Gas-‐Diffusion 

Microextraction 

Manuel Cruz, Inês M. Valente, Luís M. Gonçalves, João P. Pacheco, José A. Rodrigues, Aquiles 

A. Barros 

60 

61 

62 

63 

64 

66 

67 



PB 2 

Identificação de solventes voláteis por meio de nariz eletrônico de poli(sulfeto 

de fenileno-‐fenilenoamina) dopado eletroquimicamente 

Renata Lippi, Rosamaria W. C. Li, Jonas Gruber 

PB 3 Non-‐Usual Features of Haem Proteins at Pyrolytic Graphite Electrodes 69 

Patrícia M. Paes de Sousa, Sofia R. Pauleta, M. Lurdes Gonçalves, Graham W. Pettigrew, 

Isabel Moura, José J. G. Moura, M. Correia dos Santos 

PB 4 Evaluation of Antioxidant Capacity by potentiostatic electrolyses 70 

Juliana Marques, Raquel Oliveira, Fátima Bento, Dulce Geraldo, Paula Bettencourt 

PB 5 

PB 6 

PB 7 

PB 8 

PB 9 

PB 10 

PB 11 

Evaluation of gallic acid antioxidant activity based on its extensive oxidation 

promoted by electrochemical methods 

Raquel Oliveira, Juliana Marques, Fátima Bento, Dulce Geraldo, Paula Bettencourt 

Thiol monolayers on bismuth electrodes for organic matter fouling prevention 

in the voltammetric stripping analysis of heavy metals 

María de la Gala Morales, Eduardo Pinilla Gil, Lorenzo Calvo Blázquez 

Electrochemiluminescence of luminol/H 2 O 2 system catalyzed by ferrocenes 

derivatives in solution on ITO electrode 

Diogo Ramadas, Ana S. Viana, A.C. Cascalheira 

Estudio ciclovoltamperométrico de Nimodipina sobre electrodos de carbono 

vítreo modificados con nanotubos de carbono 

Juan Arturo Squella, Luis J. Núñez-‐Vergara, Manuel López López 

Iron (II) and Ruthenium (II) Cyclopentadienyl Derivative Complexes: new 

potential antitumor agents 

Milan N. Chhaganlal, M. H. Garcia, M. P. Robalo, V. Moreno 

Cytotoxicity Studies and DNA Interaction of New Ruthenium(II) 

Cyclopentadienyl Complexes with Nitrogen Coordinated Ligands 

Tânia S. Morais, M. H. Garcia, M. P. Robalo, A.Valente, V. Moreno, M. Font-‐Bardia, T. Calvet, 

J. Lorenzo, F. X. Avilé 

several potential anti-‐tubercular drugs: isoniazid and thiobenzanilide 

derivatives 

M. Cristina Ventura, A. Catarina Bastos, M. João Sarmento, João Manso, Susana Borges, 

Vanessa Miranda, Susana Santos, Filomena Martins 

PB 12 Bacterial cellulose: A new material for cell immobilization in biosensors 78 

Manuel J. Matos, Nelson A. F. Silva, Amin Karmali, Edison Pecoraro 

PC 1 

A Conducting Polymer / Self-‐Assembled Monolayer Modified Electrode for the 

Determination of Ascorbic Acid 

José Carlos A. Mesquita, Sónia Maria A. Fernandes, Jorge M. G. Teixeira 

PC 2 Carbon paper-‐supported Pd nano materials for the oxygen reduction reaction 80 

Cristina Oliveira Rosa Rego, Ana Maria Rego 

PC 3 

PC 4 

PD 1 

Formation of mixed self-‐assembled monolayers of mono-‐ and dithiols on 

Au(111) 

Teresa Pineda Rafael C. González-‐Cano, Rafael Madueño, Manuel Blázquez 

Electrochemical control on the formation of mixed 11-‐mercaptoundecanoic 

acid and octanethiol self-‐assembled monolayers on Au(111) 

Teresa Pineda Zoilo González-‐Granados, Rafael Madueño, Manuel Blázquez 

In-‐situ study of corrosion morphology of a duplex stainless steel in a 

concentrated LiBr solution and in an impure phosphoric acid solution by 

confocal laser scanning microscopy (CLSM) 

Jose García-‐Antón, R. Leiva-‐García, M.J. Muñoz-‐Portero 

68 

71 

72 

73 

74 

75 

76 

77 

79 

81 

82 

83 



PD 2 Copper corrosion in soils contaminated with chloride ions 84 

Carla Barradas Dias, M. M. M. Neto, I. T. E. Fonseca 

PD 3 

PD 4 

PD 5 

PD 6 

PD 7 

PD 8 

PD 9 

PE 1 

PE 2 

PE 3 

Estudo da eficiência de duas técnicas na remoção de cloretos em amostras de 

uma bala de canhão de um naufrágio do séc. XVIII 

João Carlos Coelho, M. D. Carvalho, I. T. E. Fonseca 

Electrochemical characterization of polypyrrole-‐based conducting fabrics in 

different pH media 

Javier Molina, Javier Fernández, Ana Isabel del Río, José Bonastre, Francisco Cases 

Influence of Molybdenum on electronic structure of passive films on stainless 

steels 

Maria Alice Catarino, M.I. Godinho, M. da Cunha Belo, A.M.P. Simões, M.J. Ferreira, M.F. 

Montemor 

Corrosion behaviour of quaternary bronzes in slightly passivating 

environments 

Mariano Pérez Maurizia Calvisi, Gemma González-‐Mesa 

Complementary application of localized and electrochemical techniques to 

reveal self-‐healing ability in small defects 

Maryna Taryba, D. Snihirova, S. Lamaka, M.F. Montemor, M.G.S.Ferreira 

Gold Electrodeposition from Ionic Liquids: An Alternative to Conventional 

Aqueous Baths 

Carmen M. Rangel, A.I.de Sá, S. Quaresma, S. Eugénio, R. Vilar 

Effect of chloride and sulphate ions on the electrochemical behaviour of an 

austenitic stainless steel, the HAZ and the welded metal in phosphoric acid 

medium at different temperatures 

Jose García-‐Antón, Blasco-‐Tamarit, E, García-‐García, D.M, Ibáñez-‐Ferrándiz, M.V 

Some aspects of the electrochemical reduction of the herbicide 

imazamethabenz acid on mercury electrodes 

Sara Pintado, Mercedes Ruiz Montoya José Miguel Rodríguez Mellado 

Electrochemical and Spectroelectrochemical Study of Alkyl-‐Substituted 

Heptathienoacenes 

Cristina Capel Ferron, B. Vercelli, G. Zotti, Mingqian He, Weijun Niu, V. Hernández, J. T. 

López Navarrete 

Evaluation of the antioxidant capacity of imidazoimidazole phenolic derivatives 

by cyclic voltammetry 

Filipa Gomes, A.P. Bettencourt, C. Correia, M.A. Carvalho M.F. Proença 

PE 4 Complexes for NLO: Cyclic Voltammetry Study 95 

Ana Margarida Santos, J. Mendes, Tiago J. L. Silva, M. H. Garcia, M. P. Robalo 

PE 5 Electrochemical studies of CuI-‐scorpionate complexes 96 

Luísa Martins, Riccardo Wanke, Armando Pombeiro 

PE 6 

PE 7 

Electrochemical behaviour of C-‐functionalized or substituted-‐pyrazolyl 

scorpionate cobalt complexes 

Telma F.S. Silva, Luísa M.D.R.S. Martins, Armando Pombeiro 

Electrochemical behaviour of the novel scorpionate and pyrazole 

dioxovanadium complexes 

Konstantin V. Luzyanin, Telma F.S. Silva, Luísa M.D.R.S. Martins, Armando Pombeiro 

85 

86 

87 

88 

89 

90 

91 

92 

93 

94 

97 

98 



PE 8 

PE 9 

PE 10 

PE 11 

PE 12 

PE 13 

PE 14 

Electrochemical behaviour of para-‐substituted 3-‐(phenylhydrazo)pentane-‐2,4-‐ 

diones 

Kamran T. Mahmudov, Maximilian N. Kopylovich, Luísa Martins, Fátima Guedes da Silva, 

Maxim L. Kuznetsov, Telma F.S. Silva, João J. R. Fraústo da Silva, Armando Pombeiro 

Redox behavior of dinuclear iron(II) and ruthenium(II) complexes as potential 

molecular wires 

Ana Catarina Sousa, Vanda Pacheco, M. Paula Robalo 

Investigation of 4-‐dimethoxymethyl-‐ and 4-‐formyl-‐substituted 1,4-‐ 

dihydropyridine redox reactions 

Anna Lielpetere, Inguna Goba, Baiba Turovska 

Redox properties of antitumor active organotin(IV) complexes containing 1-‐(4-‐ 

chlorophenyl)-‐1-‐cyclopentanecarboxylato ligands 

Elisabete Alegria, Xianmei Shang Xianggao Meng Qingshan Li, M. Fatima C. Guedes da Silva, 

Armando J.L. Pombeir 

Synthesis and electrochemical studies of molecular wires based on dinuclear 

Pd and Ru OPE and OTE rods 

João Figueira, José Carlos Mesquita, Kari Rissanen, João Rodrigues 

Electrochemical studies on luminescent bis-‐calix[4]arene-‐based poly(p-phenylene 

ethynylene) copolymers 

Maria Paula Robalo, Hugo S. Pinto, Alexandra I. Costa, José V. Prata 

Ruthenium (II) and Iron (II) Complexes bearing low band-‐gap thiophenic ligands 

as possible NLO switches 

Tiago J. L. Silva, Paulo J. G. Mendes, M. Helena Garcia M. Paula Robalo 

PE 15 Electrocrystallization of (DT-‐TTF)2[M(mnt)2] on microelectrodes 106 

Rafaela A. L. Silva, Mónica Afonso, Manuel J. Matos, Dulce Belo, Manuel Almeida 

PE 16 An electrochemical study of Schiff-‐base oxovanadium (IV) complexes 107 

Faranak Bishehsari, A. Rouhollahi, S. Rayati 

99 

100 

101 

102 

103 

104 

105 



Plenary Lectures 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society PL 01 

Electron Reservoir Activity of High-Nuclearity T ransition 

Metal Carbonyl Clusters 

Piero Zanello 

Department of Chemistry of the University of Siena, Via A. De Gasperi, 2 - 53100 Siena, Italy 

zanello@unisi.it 

Metal carbonyl clusters (MCC) are molecules or molecular ions perfectly defined in 

size, composition and structural details, which belong by size to the field of 

nanomaterials. 

The structures of high nuclearity MCC result from subtle balances between the M-M 

and M-CO interactions and usually adopt close-packed structures in which a chunk of 

ccp or hcp metal lattice is surrounded by a shell of CO ligands. 

Very often, such derivatives display a multivalent behaviour affording out-and-out 

reversible electron cascades [1]. 

In addition, the presence of interstitial or semi-interstitial atoms of the main group 

elements (E = C, N, P, etc.), establishing several M-E int interactions and contributing to 

the number of cluster valence electrons with no sterical requirements on the cluster 

surface, in many cases increases such uncommon electron transfer properties. 

As illustrated in Figure 1, a quite representative example is for instance offered by the 

hexa-anion [Ni 32 C 6 (-CO) 36 ] 6- [2]. 

Figure 1. Cyclic and d.c. voltammetric profiles recorded at a Pt electrode in MeCN 

solution of [Ni 32 C 6 (-CO) 36 ] 6- . 

The electrochemical and spectroelectrochemical behavior of a variety of high nuclearity 

metal-carbonyl clusters will be presented. 

Acknowledgments: The financial support of Miur (PRIN 2008) is gratefully acknowledged. 

References 

Metal Clusters in Chemistry 

Braunstein, P.; Oro, L.A.; Raithby, P.R. Eds., Wiley-VCH, Vol. 2, 1999, 1137-1158; 

(b) Collini, D.; Femoni, C.; Iapalucci, M.C.; Longoni, G.; Zanello, P.; Perspectives in 

Organometallic Che, Screttas C.G. and Steele B.R. Eds., RSC, 2003, 183-195. 

[2] Calderoni, F.; Demartin, F.; Fabrizi de Biani, F.; Femoni, C.; Iapalucci, M.C.; Longoni, G.; 

Zanello, P.; Eur.J.Inorg.Chem., 1999, 663. 



Electron T ransfer in Nanostructures of Gold Substrates 

Modified with SA M and Gold Nanoparticles. 

M. Blázquez, T. Pineda, R. Madueño, D. García-Raya 

Departamento de Química Física y T.A., Universidad de Córdoba, Spain 

mblazquez@uco.es 

Nanoscale charge transfer is important in fundamental science and applications in 

molecular electronics including sensors, photonics, electrocatalysis, and solar 

photoconversion. Progress in the nanoscale charge transfer requires interdisciplinary 

collaboration combining a wide range of materials synthesis and characterization. 

Important classes of materials at the nanoscale are metal colloids and nanocrystals. The 

low dimensions of these materials (1-20 nm) confer them unique properties. The ability 

to construct well-defined nanostructures by bottom-up approaches is a major goal in the 

field of nanoscale science and technology. In recent years, nanoparticles have been the 

subject of numerous investigations being widely accepted as ideal building blocks due to 

the ease of preparation and the accurate control over particle size and shape. Surface 

derivatization schemes have been developed employing self assembled monolayer 

(SAM) with special terminating groups which typically induce nanoparticles 

organization on the surface. The SAM is prepared by the spontaneous adsorption of 

molecules from liquid or gas phases producing crystalline or semi-crystalline structures 

on the substrate surfaces. The high affinity of thiol groups to coin metals generates well 

organized layers with a variety of chemical functions exposed to the interface. Many 

applications of nanoarchitectures require chemical, optical or biological signals to be 

transformed into electrical signals that are readable to modern electronic equipment. 

Therefore, the ability to allow electron communication between nanoparticles and the 

underlying substrate is essential for these applications. In this work we make a revision 

of several procedures for SAM preparation on Au (111) single crystals. The key point is 

the preparation of defect free SAMs that may show an electron transfer blocking 

behavior [1]. We study some strategies for preparation of gold nanoparticles of different 

sizes [2] and characterize the properties of the nanostructured material obtained by the 

combination of the SAM and nanoclusters on a single crystal substrate 

(Au(111)/SAM/AuNP). It can be shown that electron communication between the 

anchored AuNPs and the underlying gold substrate occurs through the insulating 

sandwiched monolayer. Under these conditions, the electron transfer occurs by a 

tunneling process across the bridging molecules. A general discussion of the 

electrochemical behavior of nanoparticle array electrodes on the basis of different 

surface methods is carried out. 

Acknowledgments: Project CTQ2007-62723/BQU (MEC) and Junta de Andalucía 

References 

[1] García-Raya, D.; Madueño, R.; Blázquez, M; Pineda, T.; J.Phys.Chem. C, 2010, 114, 3568. 

[2] Viudez, A. J.; Madueño R.; Pineda, T.; Blázquez, M.; J.Phys.Chem. C, 2006, 110, 17840. 



Espectroscopia de impedância electroquímica aplicada a 

estudos de corrosão 

João C. Salvador Fernandes 

ICEMS, Instituto Superior Técnico, TULisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal 

joao.salvador@ist.utl.pt 

A Espectroscopia de Impedância Electroquímica é uma técnica de grande utilidade para 

o estudo do comportamento face à corrosão de sistemas metal/meio e, em particular, 

para a investigação dos mecanismos reaccionais envolvidos. 

Na análise dos resultados de EIE podem ser usadas duas abordagens distintas: na 

primeira, que será aqui estudada com maior detalhe, utiliza- 

 

complexidade com base na cinética das reacções heterogéneas envolvidas. 

A primeira abordagem baseia-se no facto de, em princípio, qualquer célula 

electroquímica poder ser representada por um modelo eléctrico. Assim, uma interface 

eléctrodo/electrólito na qual ocorra uma determinada reacção electroquímica será 

análoga a um circuito eléctrico, formado por um conjunto de resistências, condensadores 

e, eventualmente, indutores. É nesta analogia que reside uma das principais vantagens da 

impedância electroquímica, já que torna possível a caracterização de um sistema 

electroquímico através do seu "circuito eléctrico equivalente" que apresenta a mesma 

resposta de impedância e que deverá ter um significado físico coerente. 

Para que um estudo de EIE seja válido, será necessário encontrar um circuito 

equivalente que permita separar as contribuições dos diferentes processos e quantificar 

os parâmetros relativos a cada um deles. Nos últimos anos, com o grande incremento 

verificado na utilização da técnica e com a generalização do uso de software de ajuste 

automático de resultados, utilizadores menos experientes têm sido tentados a aceitar 

qualquer circuito equivalente que se ajuste aos dados experimentais, sem olhar ao 

significado físico desse circuito. Desta forma, vários circuitos sem correspondência 

lógica a processos físicos têm surgido na literatura. 

O presente trabalho apresenta uma discussão dos princípios a seguir na escolha de um 

circuito equivalente, sendo ilustrado por vários exemplos de aplicações da técnica aos 

estudos de corrosão. 



Dynamic Electrochemical Studies of Redox Proteins 

Margarida M. Correia dos Santos 

Centro de Química Estrutural, IST, Av. Rovisco Pais, 1049-001, Lisboa, Portugal 

mcsantos@ist.utl.pt 

The use of voltammetric techniques is well proved nowadays in unravelling important 

aspects of the chemistry of metalloproteins and metalloenzymes [1,2]. Unlike the more 

conventional and widespread used of potenciometric titrations, voltammetric methods 

allow in situ measurements of reduction potentials together with the acquisition of 

information about the kinetics of the electrode reactions as well of relevant parameters 

of coupled reactions including catalysis. 

It is now well recognized the electron transfer process occurring between a redox protein 

and a solid electrode is a protein electrode surface recognition process A large effort has 

been put forward to understand and control the way the protein surface interacts with the 

electrodes and nowadays the problem is quite mastered. 

 

advantages over bulk titrations. However a wealth of information can be obtained by 

these methodologies that quite overpass the "static" utilization of the technique. The 

study of electron transfer (intra and intermolecular), recognition of redox partners and 

the observation of catalytic currents, for example, puts the methods on a dynamic range 

of utilization. 

Some of these topics will be covered in this lecture [3-8]. 

References 

[1] Armstrong, F.A.; Bioelectrochemistry (Ed.: Wilson G..S.) in Encyclopedia of Electrochemistry 

(Eds: Bard, A..J.;.Stratmann, M.)., Vol.9, Ch.1, 13, Wiley-VCH, 2003. 

[2] Léger, C.; Bertrand, P. Chem.Rev., 2008, 108, 2379. 

[3] Santos, M.M.C.; de Sousa, P.M.P.; Gonçalves, M.L.S.; Krippahl, L.; Moura, J.J.G.; Lojou, E. ; 

Bianco, P. J. Electroanal. Chem., 2003, 541, 153. 

[4] Santos, M.M.C.; de Sousa, P.M.P.; Gonçalves, M.L.S.; Romão, M..J.; Moura, I. ; Moura, J.J.G. 

Eur. J. Biochem., 2004, 271, 1329. 

[5] Santos, M.; Santos, M.M.C.; Gonçalves, M.L.S.; Costa, C.; Romão, J.C.; Moura, J.J.G. J. Inorg. 

Biochem., 2006, 100, 2009. 

[6] de Sousa, P.M.P.; Pauleta, S.R.; Gonçalves, M.L.S.; Pettigrew, G.W.; Moura, I.; Santos, 

M.M.C.; Moura, J.J.G. J Biol Inorg Chem., 2007, 12, 691. 

[7] de Sousa, P.M.P.; Pauleta, S.R.; Rodrigues, D.; Gonçalves, M.L.S.; Pettigrew, G.W.; Moura, I.; 

Moura, J.J.G.; Santos, M.M.C. J Biol Inorg Chem., 2008, 13, 779. 

[8] de Sousa, P.M.P.; Pauleta, S.R.; Gonçalves, M.L.S.; Pettigrew, G.W.; Moura, I.; Moura, J.J.G.; 

Santos, M.M.C. Submitted for publication in Angewandte Chemie. 



Electrochemistry of molecules with two (or more) redox 

centers 

 

J. Heyrovský Institute of Physical ChemistryCzech Rep. 

jiri.ludvik@ jh-inst.cas.cz 

Molecules of organic or coordination compounds have often two or more redox centers. 

These centers may be independent or communicating, according to their mutual distance 

and extent of electron delocalization between them. The most attractive is the case of 

strong interaction between the centers, when the redox active groups do not preserve 

their typical redox properties and create a new electron system with its specific redox 

reactivity. To understand the structural rules and eventually to tune the redox properties 

is an interesting theme for fundamental research as well as for development of catalysts, 

dyes, pharmaceutical products, agrochemicals etc. 

Electrochemical approach is a very suitable experimental tool for examination of such 

intramolecular electron interactions. In the contribution, several examples will be 

mentioned: azines, where the N-N bond prevents the electron interaction of two C=N 

double bonds [1], mono-oximes of aromatic 1,2-diketones, where two isomers have 

different reduction behaviour [2]. Next examples are represented by Fischer 

aminocarbene complexes [3-4] and by various mono-and dinuclear transition metal 

complexes bearing ferrocene as 1) another redox center able to form a new delocalized 

system [5-8], 2) as an electrochemical probe [9-10]. Finally, the recent investigation of 

redox properties of two types of polynitrocompounds (geminal dinitroderivatives and 

mono-, di-, tri- and tetranitrocalixarenes) will be discussed. 

Acknowledgments: The work was supported by the grants IAA 400 400 813 (Grant Agency of the 

Academy of Sciences of the Czech Republic) and ME 09 002 (Ministry of education, youth and 

sports of the Czech Republic). 

References 

[1] Surname, A. B.; Surname C. D. Journal, Year, volume, starting page. 

[1] Zuman, P.; Ludvík, J. Tetrahedron letters, 2000, 41, 7851. 

[2] Celik, H.; Ludvík, J.; Zuman, P. Electrochemistry Communnication, 2006, 8, 1749. 

[3] Meca, L.; D.; Ludvík, J.; I.; , P. Organometallics, 2004, 23, 2541. 

[4] Hoskovcová, I.; J.; Meca, L.; Tobrman, T.; D.; Ludvík, J. Electrochim. 

Acta, 2005, 50, 4911. 

[5] Organometallics, 1996, 15, 543. 

[6] Lukesova, L.; Ludvik, J.; Cisarova, I.; Stepnicka, P. Coll. Czech. Chem. Commun., 2000, 65, 

1897. 

[7] Auzias, M.; Süss-J. Inorg. Chim. Acta, 2007, 360, 2023. 

[8] Auzias, M.; Therrien, B.; Süss-J. Organomet. Chem., 2007, 

692, 755. 

J. Organomet. Chem. 2001, 637-639, 291. 

Chem. Eur. 

J., 2004, 10, 2058. 



Key Notes 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society K N 01 

Novel layer-by-layer interfacial [Ni(salen)]-polyelectrolyte 

hybrid films 

C ristina F reire 

REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do 

Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal 

acfreire@fc.up.pt 

The synthetic derivatisation of [M(salen)]-type complexes with ionic groups can provide 

building blocks for the fabrication of hybrid films using the electrostatic layer-by-layer 

(LBL) self-assembly technique. This technique affords molecular-level control over 

fabrication of thin films by precise control of components assembly.[1] Specifically, it is 

an ideal tool for tailoring the properties of multilayer films on the nanometer scale by 

electrostatic deposition of charged [M(salen)]-type complexes functionalized with 

receptor groups and organic polyelectrolytes with a view to sensor application. 

In this work the novel multilayer films containing cationic phosphonium-derivatized 

Ni(salen)-type complex and poly(sodium-4-styrenesulfonate (NaPSS) was assembled 

onto quartz, mica and Au surfaces using LbL technique, Figure 1. [2] UV-visible and 

QCM responses for the multilayer films show regular stepwise growths and the 

signature of strong electrostatic interactions between the component layers. Permeability 

of the films to the redox probe [Fe(CN) 6 ] 3/4 was studied by cyclic voltammetry (CV) 

and electrochemical impedance spectroscopy (EIS). The EIS data were interpreted using 

a capillary membrane model (CMM), to yield values of coverage, apparent charge 

transfer resistance, double layer capacitance, pore size and diffusion coefficient. The 

recognition properties towards Ca 2+ and Ba 2+ of hybrid [Ni(salen)]-PSS LbL thin films 

assembled onto Au electrodes was also studied by CV and EIS by using the redox 

couple probe [Fe(CN) 6 ] 3-/4- . 

N 

N 

Ni O 

O 

t-Bu 

PPh 3 

PPh 3 

N 

N 

Ni 

t-Bu 

O 

O 

t-Bu 

PPh 3 

t-Bu 

PPh 3 

PSS 

Film bilayer (xn) 

NaPSS = 

SO 3 Na 

* 

PAH 

PSS 

Precursor bilayer (x2) 

PAHCl = 

NH 3 Cl 

* 

Modified substrate 

Figure 1. Schematic representation of LBL films and individual PAHCl, NaPSS and [Ni(salen)] 2+ 

components. 

Acknowledgments: Partially funded by F CT, through project Ref PTDC/QUI/67786/2006. 

References 

[1] Decher, G. Science 1997, 277, 1232. 

[2] Patrício, S.; Cruz, A.I.; Biernacki, K.; Ventura, J.; Eaton, P.; Magalhães, A. L.; Moura, C.; 

Hillman , A. R.; Freire, C. Langmuir, 2010, in press: DOI: 10.1021/la1006956 



T ratamentos de Superfície em Ligas de Alumínio de Aplicação 

Aeronáutica 

Mário F reitas 

OGMA-Indústria Aeronáutica de Portugal, 2615-173 Alverca, Portugal 

mario.c.freitas@ogma.pt 

Devido às suas diversas propriedades o alumínio é amplamente utilizado na indústria 

aeronáutica e aeroespacial. Note-se no entanto que o referido metal no seu estado puro 

apresenta-se demasiado macio e fraco para suportar grandes esforços, possuindo baixa 

resistência mecânica quando sujeito a altas temperaturas. Para contornar esta situação, o 

alumínio pode ser submetido a inúmeros tratamentos, bem como adição de elementos 

de liga. 

Embora a adição de elementos de liga (ex.: cobre, magnésio, silício e zinco) aumente a 

resistência mecânica do alumínio, por outro lado diminui a capacidade do mesmo na sua 

capacidade de resistência à corrosão. 

Na indústria aeronáutica, a corrosão nas estruturas de ligas de Alumínio é uma das 

maiores causas de custos de manutenção. 

Neste âmbito, a OGMA Indústria Aeronáutica de Portugal, apresenta-se como uma 

empresa de Manutenção e Fabricação aeronáutica, onde se encontra inserida uma área 

de Tratamentos Químicos e Electroquímicos com capacidade de tratar várias ligas 

metálicas, entre as quais ligas de alumínio. 

Os processos especiais existentes na OGMA para tratamento de ligas de Alumínio 

correspondem a: 

- Oxidação Anódica Crómica; 

- Oxidação Anódica Sulfúrica; 

- Conversão Química. 

É de referir que estes revestimentos possuem na sua composição cromatos , o que se por 

um lado lhes confere a capacidade de inibidor de corrosão superior, por outro lado 

também os torna ambientalmente pouco recomendaveis. 

As fortes propriedades de oxidação dos cromatos implicaram a realização de estudos 

minuciosos relativamente ao seu uso, sendo que nos finais da década de 70 deu-se inicio 

à pesquisa para substituição destes revestimentos em ligas de alumínio. 

Enquadrado neste tema, as novas tecnologias que surgiram e que têm sido alvo de 

avaliação para implementação, por parte da OGMA dizem respeito a: 

- Tartaric Sulfuric Anodizing (TSA), com alternativo ao processo de Oxidação 

Anódica Crómica; 

- Sol-Gel e Prekote, como alternativos ao processo de Conversão Química. 

Estes processos alternativos, bem como outros que se encontram em fase de 

investigação irão certamente desempenhar um papel importante num futuro próximo 

pois, as preocupações ambientais assumem cada vez mais um papel de relevo no Mundo 

Global e às quais a Industria Aeronáutica não é alheia. 



" Smart " self-healing coatings for active corrosion protection 

M.L. Zheludkevich, M.G.S. Ferreira 

CICECO, DECV, University of Aveiro, Aveiro, 3810-193, Portugal 

mzheludkevich@ua.pt 

The application of organic coatings is the most common and cost effective 

method of protection and improving durability of metallic structures in corrosive 

environments. However the degradation processes develop faster after disruption of the 

protective ba- 

coatings is necessary to provide long-term effect. 

The present work summarizes recent developments in the area of the new 

active multi- lease nanocontainers 

incorporated into the polymer coating matrix. The nanocontainer (or nanoreservoir) is a 

nanosized volume filled with an active substance confined in a porous core and/or a 

shell which prevents direct contact of the active agent with the adjacent environment. A 

multi-level self-healing approach combines - within one system - several damage 

prevention and reparation mechanisms including trapping of corrosive ions, corrosion 

inhibition and water displacement from active defects. 

Several types of nanoreservoirs of corrosion inhibitors, nanotraps and were 

microcapsules with water displacers are developed, introduced to the coating system and 

tested in terms of active corrosion protection. 

The novel experimental approaches to study self-healing properties of the 

active protective coatings are also addressed in the present paper. 



Evaluation of antioxidant activity: a reagentless 

electrochemical approach 

Dulce Geraldo, Fátima Bento 

Departament of Chemistry, Universidade do Minho, 4710-057 Braga 

gdulce@quimica.uminho.pt 

The growing interest in the study of the action of antioxidants in health and 

biotechnology has led to the development of different analytical methods for the 

evaluation of the antioxidant capacity of these compounds. 

Cyclic voltammetry has been widely used in the analysis of samples containing mixtures 

of antioxidants. The analysis of voltammograms gives qualitative information, which 

relates to the identification of peaks, or waves resulting from overlapping voltammetric 

peaks. This information is usually used to evaluate the power of the antioxidants present 

in the sample. Quantitative information can be achieved by following two different 

approaches, consisting in measuring the current intensity at a fixed potential, or the area 

under the anodic scan of voltammograms. The values of current or area are converted to 

relative values of antioxidant activity against a model antioxidant. Besides cyclic 

voltammetry, electrochemical methods have been used as an alternative to optical 

methods for monitoring the consumption of reactive species, such as the DPPH [1] . Other 

studies reported the use of coulometric titration at constant current to generate reactive 

species such as the cation radical ABTS [2] , Ce(IV) [3] , Cl 2 

[4, 5] and Br 2 [5] . As the reactivity 

of these species is different from that of naturally ROS involved in oxidative damage / 

oxidative stress, the significance of these results is rather limited and may lead to an 

underestimation or overestimation of the antioxidant activity according to the relative 

value of the reduction potential of reactive species. Likewise, the difference between the 

reduction potentials of the reactive species used in the various methods difficult the 

establishment of a parallelism between the results from these methods. 

The direct analysis of electron transfer with the antioxidants using controlled potential 

exhaustive electrolysis can overcome these limitations. 

In this work, we present a new analytical approach for evaluating the antioxidant 

activity of chemical species in synthetic solutions or in natural systems, designed to 

measure their reactivity against specific ROS (from the O 2 to the HO • ) under defined 

experimental conditions (eg pH). The method is based on the response of antioxidants 

during electrolysis conducted at a fixed potential, simulating an oxidative attack by a 

natural ROS. 

References 

[1] Milardovic, S.; Ivekovic, D.; Grabaric B. S. Bioelectrochemistry, 2006, 68, 175. 

[2] Alonso, A. M.; Dominguez, C.; Guillén D. A.; Barroso, C. G. J. Agric. Food Chem., 2002, 50, 

3112. 

[3] Ferreira, R. Q.; Avaca, L. A. Electroanalysis 2008, 20, 1323. 

[4] Addullin, I. F.; Turova, E. N.; Ziyatdinova, G. K.; Budnikov, H. C. Journal of Analytical 

Chemistry , 2002, 57, 730. 

Talanta, 2006, 68, 800. 



Electrochemical degradation of organic pollutants: 

optimization of the experimental conditions 

Ana Lopes 

UMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal 

analopes@ubi.pt 

Biological degradation is the cheapest process for removal of organic pollutants from 

wastewaters. However, some compounds have low biodegradability or give origin to 

biotic products that persist in the receiving waters. When conventional biological 

treatments fail, a tertiary process, like chemical or electrochemical coagulation, 

adsorption or membrane filtration, is usually performed, with the disadvantage of sludge 

formation. Other alternatives, such as chemical oxidation with strong oxidants and 

advanced oxidation processes, besides being quite expensive, still present operational 

problems. 

Anodic oxidation techniques have also shown to be very efficient in the degradation of 

organic persistent pollutants. The use of these processes in wastewaters treatment has 

been intensively investigated in the last two decades [1,2]. The materials that can be 

used as electrodes are numerous and some of them are extraordinary promising. In 

particular, boron doped diamond (BDD) anodes have received great attention in the last 

years, due to their unique characteristics of mechanical and electrochemical stability, 

wide potential window for oxygen evolution and ability to produce radical species 

capable of oxidation of most of the organic pollutants [2-7]. 

Although anodic oxidation with BDD electrodes can be very effective, energetic costs 

are a drawback in the application of these techniques at industrial scale. This way, the 

optimization of experimental parameters and hydrodynamic conditions, in order to 

reduce maintenance costs, are a requirement for the implementation of these processes. 

In this study, the influence of pollutant type and concentration, electrolyte concentration, 

initial pH, applied current density, operation mode, stirring speed and recirculation flow 

rate in the organic load removal are evaluated. 

Acknowledgments: The financial support of Fundação para a Ciência e a Tecnologia, F CT, 

PDCT/AMB/59392/2004, PDCT/AMB/59388/2004, PTDC/CTM/64856/2006 and PTDC/AAC- 

AMB/103112/2008 and Adamant Technologies are gratefully acknowledged. 

References 

[1] Juttner, K., Galla, U., Schmieder, H., Electrochim. Acta, 2000, 45, 2575. 

[2] Martínez-Huitle, C.A., Ferro, S., Chem. Soc. Rev., 2006, 35, 1324. 

[3] Morão, A., Lopes, A., Pessoa de Amorim, M.T.,.Gonçalves, I., Electrochim. Acta, 2004, 49, 

1587. 

[4] Panizza, M., Cerisola, G., Electrochim. Acta, 2005, 51, 191. 

[5] Pacheco, M.J., Morão, A., Lopes, A., Ciríaco L. , Gonçalves, I., Electrochim. Acta, 2007, 

53, 629. 

[6] Ciríaco, L., Anjo, C., Correia, J., Pacheco, M. J., Lopes, A., Electrochim. Acta, 2009, 54, 1464. 

[7] Santos, V., Diogo, J., Pacheco, M.J.A., Ciríaco, L., Morão, A., Lopes, A., Chemosphere , 2010, 

79, 637. 



Assessing Performance and Degradation Mechanisms in 

Proton Exchange Membrane Fuel Cells 

C.M. Rangel, R.A. Silva, T.I. Paiva 

Laboratório Nacional de Energia e Geologia, Paço do Lumiar 22, 

Unidade de Pilhas de Combustível e Hidrogénio 1649-038 Lisboa, Portugal 

carmen.rangel@ineti.pt 

Fuel cells, considered the next generation of power sources, exhibit high generation 

efficiency and low environmental impact. From the different type of fuel cells available, 

the Proton Exchange Membrane Fuel Cell, PEMFC, has shown rapid development in the 

last decade, with a great increase in the power density to specific power ratio. 

Portable and mobile as well as stationary applications of fuel cells have been 

demonstrated. Furthermore, a variety of energy conversion applications, in association 

with renewable sources for fuel and oxidant supply, have been put forward and are seen 

as viable options in future highly distributed power generation. 

A considerable research effort in Materials Science and Electrochemistry is needed in 

order to increase the knowledge about fuel cells lifetime and reliability. In this work, 

the modular character of a PEM fuel cell will serve to examine the factors affecting 

performance, focussing on electrode kinetics and operating conditions together with the 

issues of thermal and water managements. A comparison will be done for PEM fuel 

cells fed by gas and liquid fuels emphasizing the effect on efficiency of the electrode 

kinetics, arising from multi-step fuel oxidation reactions and fuel crossover. 

The mechanism of ageing and degradation in fuel cells are not well understood. PEM 

fuel cell operates under very aggressive conditions in both anode and cathode. Increases 

in cell voltage leading to higher efficiencies may lead to surface oxidation of the 

supported catalyst, decreasing reaction activity and accelerating electrode degradation. 

In the case of fuel starvation, the anode potential may rise to levels compatible with the 

oxidization of water and if water is not available, oxidation of the carbon support will 

accelerate catalyst sintering. These issues will be addressed, in order to better categorize 

irreversible changes in the kinetic and/or transport properties of the cell, demonstrating 

the use of non-destructive electrochemical as well as ex-situ approaches. 

The contribution of mathematical modeling in PEM fuel cells will be also emphasized, 

focusing the prediction of conditions for a better thermal and water management and in 

aiding design and operating strategies. 



Oral Communications 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society O A 01 

Solvay Ready for tomorrow 

Rui Rocha 

Solvay Portugal, R. Eng. Clement Dumoulin, 2625-106 Póvoa de Santa Iria, Portugal 

rui.rocha@solvay.com 

Solvay is an international industrial Group active in Chemistry, where the electrolysis 

chlor-alkali is present for over a century (since 1898). During this period, the group has 

suffered a lot of transformations (a plastics sector has appeared and, later on, a 

pharmaceuticals business that was sold in 2010) and has grown motivated by providing 

solutions to sustainability. Solvay is present in almost every continent (50 countries) and 

is the global leader in many of its main products. 

Solvay Portugal operates an integrated small plant that uses its differentiated situation 

(small, flexible and with some of the main processes used in Solvay Group) to combine 

strong human and financial resources in R&D, mainly application of new innovations to 

be replicated all over the group. For example, the high rate H2O2 plant was tested and 

optimized in our plant; Solvay Póvoa was the first plant to have membrane technology. 

Now we are preparing the future. Fully compliant with the REACH directive, the Solvay 

 

into all our business activities the triple requirement of sustainable development: 

economic growth, employment and social progress, environmental impact. Before 2020, 

the Solvay Group intends to reduce most of its emission parameters by 20%. 



Modern QSPR methodology to address non-solved solution 

electrochemistry old issues 

Luís Moreira, 1,2 Marina Reis, 1 Nelson Nunes, 1,3 Rui Filipe, 3,4 Filomena 

Martins, 1,3 Ruben Elvas Leitão 1,3 

1 CQB/FCL, Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal 

2 ISEC/UCT, Al. das Linhas de Torres, 179, 1750-142 Lisboa, Portugal 

3 

ISEL/DEQ, R. Conselheiro Emídio Navarro, 1950-062, Lisboa, Portugal 

4 

CPQ/IST, DEQB, Av. Rovisco Pais, 1049-001 Lisboa, Portugal 

lmmoreira@fc.ul.pt 

Conductivity measurements of 2,6-lutidinium chloride were performed in several 

solvents in different concentrations ranging from 0.0001 mol dm -3 to 0.02 mol dm -3 and 

temperatures (25.00 to 80.00 ºC). The obtained m = f (c) curves were adjusted to the 

FHP (Fuoss-Hsia-Prini) equation both in its full and truncated forms. The statistical 

significance of including all three adjustable parameters ( 0 m, K A , a) and further terms 

used in this equation is fully discussed. 

The large amount of data collected allowed an in-depth analysis of temperature effects 

on ionic association and mobility which has been started elsewhere [1]. In particular, the 

application of a suitable equation within a QSPR (quantitative structure-property 

relationships) context allowed a proper identification and quantification of specific ionsolvent-solvent 

interactions which play an important role in ionic association. In 

addition, the temperature dependence of the referred interactions was also scrutinised. 

The present work strongly emphasises the need to establish a modern methodology to 

address non-solved old issues such as solvent effects on association phenomena in order 

to obtain a clearer understanding of the underlying molecular events. 

References 

[1] Moreira, L.; Leitão, R. E.; Martins, F. Molecular Physics, 2006, 104, 1905. 



Investigations into the electrochemical synthesis of hydrogen 

peroxide 

Maria Campos, Sarah Ball, Rob Potter 

Johnson Matthey RG4 9NH, UK 

camposm@matthey.com 

Johnson Matthey is a specialist chemicals company with core skills in catalysis, precious 

metals, fine chemicals and process technology. In addition, it has well-established 

capabilities in proton-exchange membrane (PEM) fuel cell technology. At the JM 

Technology Centre (Reading, UK), we are investigating the adaptation of fuel cell 

technology for electro-chemical synthesis. A novel catalyst for the electrochemical 

generation of hydrogen peroxide, suitable for use in a PEM fuel cell device, has been 

discovered [1]. 

At present, this non-precious metal catalyst, based on a cobalt complex supported on 

high surface-area carbon, is being optimised and characterized by electrochemical 

techniques in a conventional 3-electrode cell and a PEM single cell. One of the 

techniques used within in the conventional 3-electrode arrangement was the rotating ring 

disk electrode. This technique was used to analyse the behaviour of the cobalt complex 

and in comparison to a 38% Pt on carbon catalyst (Figure 1). The current efficiency for 

the production of hydrogen peroxide was calculated using the ratio of the disc and ring 

currents. The Co catalyst current efficiency was found to be up to 70% for peroxide 

formation, compared to about 3% for Pt/C. 

Figure 1 Rotating ring disk voltammogram for carbon-supported Pt and Co catalysts 

in 0.1 M HClO 4 , at 10 mV s -1 at a rotating speed of 2500 rpm. 

Acknowledgments: Sarah Ball, Rob Potter, Fuel Cells group in Johnson Matthey Technology 

Centre, Reading, UK 

References 

[1] Garcia Lopez, Sonia, Potter, Robert John, Improvements in catalysts, , WO 2009/081183 A1. 



Acidity Constants of Diprotic Acids from Potentiometric 

Titrations: Principles of the Calculation Illustrated Through 

the Construction of a Simple Algorithm 

Elsa Gonçalves, 1,2 António Conceição 3 

1 Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 

1649-016 Lisboa, Portugal 

2 Instituto Politécnico de Setúbal, ESTBarreiro, Rua Américo da Silva Marinho, 

2839-001 Lavradio, Portugal 

3 Centro de Química Estrutural, Complexo Interdisciplinar, Instituto Superior Técnico, 

1049-001 Lisboa, Portugal 

emdgoncalves@fc.ul.pt 

Acidity constants are a measure of the strength of a weak acid in solution and are 

defined as the equilibrium constants of the dissociation reactions of the acid in solution. 

The pH of a solution resulting from the dissolution of a weak acid depends on the value 

of these constants, that also allows the preparation of pH buffer solutions. 

This work describes the step by step construction of an algorithm suitable for those 

calculations. The different steps of the calculation sequence are illustrated by means of a 

flow-chart [1]. The algorithm can be easily implemented in a worksheet or in 

programmable calculator with graphical capabilities. This will be exemplified by using a 

commented Excel worksheet. 

The constants calculated using this algorithm were compared with those obtained using 

the Hyperquad [2] for the titration of nicotinic acid with sodium hydroxide, figure 1. 

Figure 1 - Experimental and calculated titration curves for the reaction of 

0.100 mmol of the nicotinic acid with 0.109 M sodium 

hydroxide in 0.2 M potassium chloride. 

300 

200 

10 0 

Titration curve 

Experimental 

Calculated 

E(mV ) 0 

0 0.5 1 1.5 2 2.5 3 

-100 

-200 

-300 

Vb(mL) 

References 

[1] Conceição, A. C. L.; Minas da Piedade, M.E., J. Chem. Ed., 2006, 83, 1853. 

[2] Gans, P.; Sabatini, A.; Vacca, A., Talanta, 1996, 43, 1739. 



Functionalized carbon supported Pt-Ru electrocatalysts for 

alcohols oxidation 

J.R.C. Salgado 1 , Raquel G. Duarte 1,3 , Laura M. Ilharco 2 , Ana M. Botelho do 

Rego 2 , M.G.S. Ferreira 1,2 

1 ICEMS, 2 CQFM and IN, IST, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1, 

1049-001, Lisboa, Portugal 

3 Escola Superior de Tecnologia do Barreiro, IPS, R. Américo da Silva Marinho, 

2839-001, Barreiro, Portugal 

4 CICECO, Universidade de Aveiro, Campus De Santiago, 3810-193 Aveiro, Portugal 

jose.salgado@ist.utl.pt 

Research and development of new materials for the electrocatalytic reactions in low 

temperature alcohols fuel cells are of great importance for the viability of these systems. 

Therefore, the carbon supported Pt based materials are up to now the best 

electrocatalysts for low temperature alcohols fuel cells. However, Pt is expensive and 

easily poisoned by CO adsorptionTo overcome these drawbacks several binary Pt alloys 

have been studied [1]. Among them, the Pt-Ru alloy presents improved electrocatalytic 

behaviour. Nevertheless, the electrocatalytic activity of Pt-Ru/C is strongly dependent 

on the preparation method and on the particle size [2]. Therefore, the present research 

work reports the preparation of functionalized carbon supported Pt-Ru binary 

electrocatalysts for alcohols oxidation reaction (methanol and ethanol). The carbon 

material (Vulcan XC-72R) was modified by chemical and thermal treatments. Thus, the 

as received carbon was treated with HNO 3 , HNO 3 +H 2 SO 4 and H 2 O 2 aqueous solutions, 

in order to create surface reactive groups such as carboxylic, carbonyls and others. 

Thermal treatment of the carbon in the atmosphere was performed. The treated carbon 

samples were characterized by elemental analysis, BET, FTIR and XPS. Subsequently, 

the synthesis of the carbon supported Pt and Pt-Ru electrocatalysts was performed by 

formic acid reduction [2]. The samples were characterized by ATG, XRD, SEM/EDS, 

XPS and TEM; the alcohol (methanol and ethanol) oxidation reaction was studied by 

electrochemical techniques, namely CV, CR and EIS. 

Acknowledgments: J.R.C. Salgado acknowledges F CT Fundação para a Ciência e Tecnologia 

for the financial support of his contract under Ciência 2008 (Science 2008). 

References 

[1] L. Hansan; Z. Jiujun, Electrocatalysis of Direct Methanol Fuel Cells: From Fundamentals to 

Applications, 2009, Wiley-VCH, Weinheim. 

[2] J.R.C. Salgado, F. Alcaide, G. Álvarez, L. Calvillo, M.J. Lázaro, E. Pastor, J. Power Sources, 

195 (2010) 4022. 



Chemical Microscopy: the study of reduction-oxidation 

reactions under a stereomicroscope 


Centro de Química Estrutural, Departamento de Engenharia Química e Biológica do Instituto 

Superior Técnico, 1049-001, Lisboa, Portugal 

clementina@ist.utl.pt 

Chemical Microscopy was defined by Émile Monnin Chamot and Clyde Walter Mason 

(1915) as the study of chemical reactions under a microscope, aiming the development 

of spot tests for the identification of a wide variety of chemicals. 

The study of reductionoxidation reactions were performed under a stereomicroscope 

 

(easily available) were used. This procedure led to a better observation and 

interpretation of many redox processes such as the study of displacement reactions for 

the electrochemical series of metals (Li, Mg, Al, Zn, Sn, Pb, Cu, Hg, Ag) and the study 

of potassium permanganate as oxidizer in several oxidation states (VII, VI, V, IV, II). 

The results were used to illustrate Latimer, Frost and Pourbaix diagrams, as well as the 

balance of redox equations in high school teaching programs. 

The photomicrographs of these redox processes were obtained with a digital camera 

 

decoration of textiles such as T-shirts, aprons, coasters and other house hold items, as 

well as note books, albums, mouse pads, etc. A large collection of items were created, 

will be presented. 

Figure 1. a) Potassium permanganate solution (violet) reacting with magnesium in basic 

medium (a pellet of NaOH was added). The chemical pattern is obtained repeating four 

times the fotomicrograph. b) The end of the redox reaction, producing manganese 

dioxide (brown) and white crystals. 

a) b) 

Acknowledgments: Ciência Viva projects and MCT funding programs. 

References 

[1] Teixeira, C. Química, Boletim da Sociedade Portuguesa de Química, 2007, 107, 18. 



The Capacitive Behavior of Self-assembled 

Manganese Dioxide Thin Films 

Suh Cem Pang, Boon Hong Wee 

Department of Chemistry, Faculty of Resource Science & Technology, 

Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia. 

scpang@frst.unimas.my or suhcem@gmail.com 

Self-assembled manganese dioxide thin films were deposited directly on 

metalized plastic supporting substrates by a horizontal submersion process which 

entailed the spontaneous assembly of preformed manganese dioxide nanoparticles in the 

form of stable colloidal suspension under controlled conditions. Films with desired 

thicknesses were deposited simply by repeating the submersion process a desirable 

number of times. The surface morphological characteristics of deposited films were 

observed to be substantially affected by the deposition conditions such as duration of 

submersion, temperature, suspension concentration, pH and ionic strength of the 

suspension, as well as the post-deposition calcination temperature. Self-assembled films 

of tailored microstructure were prepared by optimizing deposition conditions and 

elucidation of the underlying deposition mechanisms. The electrochemical properties of 

self-assembled manganese dioxide films were characterized by cyclic voltammetry (CV) 

and electrochemical impedance spectroscopy (EIS) based on a standard 3-electrode 

configuration. These films were observed to exhibit excellent capacitive behavior as 

evidenced by the almost perfectly rectangular shape of cyclic voltamograms within the 

potential range of 0.0 to 1.0 V (versus SCE) in mild aqueous Na 2 SO 4 electrolyte as well 

as in polymeric gel electrolyte (Fig. 1). Nyquist plots generated from EIS data showed a 

linear vertical spike within the frequency range of 1 MHz and 10 mHz, had further 

confirmed the excellent capacitive behavior of self-assembled manganese dioxide thin 

films. The good capacitive behavior of self-assembled manganese dioxide thin films 

could be attributed to redox reactions involving homogeneous intercalation and 

deintercalation of protons and Na + ions during charging and discharging cycles. 

-film electrochemical capacitors were fabricated from 

such self-assembled manganese dioxide thin films and polymer gel electrolyte. Such 

prototypes of optimized dual-planar electrode configuration exhibited high cycling 

stability and reversibility upon prolonged cycling of more than 1,000 cycles (Fig. 2). 

The potential utility of self-assembled manganese dioxide thin films as electrode 

material for the fabrication of electrochemical capacitors or related charge-storage 

devices is therefore highly envisaged. 

Current density (A/g) 

12 

10 

8 

6 

4 

2 

0 

-2 

-4 

-6 

-8 

-10 

-12 

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 

Potential (V) 

Cycle50 

Cycle1000 

Liquid Electrolyte 

Figure 1. CV curves of thin-film electrochemical 

capacitor prototype with liquid or gel electrolytes. 

Specific capacitance (F/g) 

160 

140 

120 

100 

80 

60 

40 

20 

0 

Configuration 3 



Capacitance (F/g) 

Configuration 1, 2, and 3 

(Overlapping lines) 

Qa/Qc ratio 

0 100 200 300 400 500 600 700 800 900 1000 

Fig. 2. Cycling behaviors of electrochemical 

capacitor prototypes with different device 

configurations. 

5 

4 

3 

2 

1 

0 



Síntesis Electroquímica selectiva de y/o Hidroxido de 

Niquel con aditivos de Co y su caracterización como material 

de electrodo para baterías recargables 

Felipe J. Rodríguez Nieto, Daniela Becker, Arnaldo Visintin 

INIFTA, Facultad de Ciencias Exactas, UNLP, CCT La Plata-CONICET, Diag. 113 y 64. CC 16 

Suc. 4 (1900) La Plata, Argentina 

rodrini@inifta.unlp.edu.ar, coconieto@gmail.com 

El hidróxido de níquel es un material complejo y con una 

estructura que en general depende del método de preparación. Generalmente existe en 

las formas polimorficas -Ni(OH) 2 , y - Ni(OH) 2 las cuales son transformadas en - 

NiOOH y -NiOOH durante el proceso de carga-descarga del electrodo. Las actividades 

electroquímicas de estas fases difieren de una a otra debido a los cambios en su 

estructura, composición y características morfológicas que provocan cambios en los 

diversos procesos que tienen lugar durante los ciclos de carga-descarga. Por lo tanto el 

proceso de fabricación del electrodo juega un rol muy importante en la actividad 

electroquímica del hidróxido de niquel. 

En el presente trabajo se realiza el estudio del comportamiento 

electroquímico de muestras de /-Ni(OH) 2 y de -Ni(OH) 2 con adición de partículas 

de Co que han sido obtenidas a través de una indirecta precipitación electroquímica 

realizada a corriente constante (30mA/cm 2 ) usando como electrodo de trabajo una malla 

cilíndrica de Platino de alta área y como contra electrodos, dos placas porosas de níquel. 

El procedimiento experimental se ha realizado en una celda electroquímica de vidrio en 

la que se ha modificado la geometría de la celda cambiando la posición de los contra 

electrodos: (a) colocados en el mismo compartimiento, y (b) colocándolos en 

compartimientos separados por una placa porosa. 

La electrólisis se ha realizado usando solución de nitrato de níquel 0.5 M y la adición de 

Co a partir de solución de nitrato de Cobalto a fuerza iónica constante y una temperatura 

de 70ºC. El precipitado obtenido es separado y lavado hasta obtener pH neutro, 

finalmente es secado a 60 ºC por 24 h. 

El material activo obtenido es caracterizado por Difracción de rayos X (DRX), análisis 

termogravimétrico (TGA, DTA), espectroscopia infrarroja (FTIR) y microscopia 

electrónica de barrido (SEM) y de transmisión (TEM); asimismo, la perfomance 

electroquímica como material de electrodo de baterías recargables se realiza mediante 

voltamperometría cíclica, ciclos de cargadescarga y diferentes velocidades de descarga 

(rate capability) en una solución de KOH 7 M a 25 ºC. 

Los resultados muestran que la estructura de los polvos Ni(OH) 2 obtenido no es 

cristalina, y es selectiva en especial a la geometría de la celda electroquímica originada 

por la posición de los contraelectrodos, siendo -Ni(OH) 2 , para el arreglo (b) y - 

Ni(OH) 2 para el arreglo (a). Las muestras obtenidas de -Ni(OH) 2 puro y con adición 

de Cobalto muestran la mejor perfomance electroquímicas como material de electrodo 

para baterías recargables obteniéndose capacidades de 350 y 290 mAhg -1 

respectivamente. 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society O B 01 

Application of a Membraneless Extraction Module in the 

Voltammetric Determination of Sulphites in Wine 

Luís M. Gonçalves, Miriam F. Anunciação, Inês M. Valente, 

João G. Pacheco, José M. Rodrigues, Aquiles A. Barros 

Requimte, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 

Rua do Campo Alegre, no. 687, 4169-007 Porto, Portugal 

luis.goncalves@fc.up.pt 

In this work, a new methodology for the voltammetric analysis of sulphites in wine is 

proposed [1]. It makes use of a recently developed membraneless extraction module 

(MLEM) for the analysis of volatile and semi-volatile compounds [2]. Sulphites are 

widely used as preservatives in the food industry for their several roles including the 

prevention of undesirable microbial growth and oxidation processes. Among a whole 

variety of methodologies proposed for the determination of sulphites in wine, the most 

used are based on the classical Monier-Williams procedure and the also ancient Ripper 

method. Nevertheless, voltammetric-based methodologies appear to be the most 

accurate ones. Square-wave voltammetry (SWV) is very advantageous in the 

determination of sulphites since there is a direct detection, i.e. it is the SO 2 molecule that 

is instrumentally measured in the electrode [3]. The major drawback when using 

voltammetry is the previous analyte extraction step required since wine is such a 

complex matrix. The extraction process is based on a MLEM that works with the same 

principles of pervaporation however it does not require a membrane, and therefore does 

not have the associated problems with its use. The sample is placed inside the module 

and the volatile compounds evaporate to the headspace. Inside the module there is a 

suspended small reactor, where a small volume of an acceptor solution is placed. After a 

period of time, the acceptor solution is collected and analyzed by SWV. The proposed 

method was validated by comparison to the reference methodology. It showed 

repeatability (RSD lower than 5%) and linearity (between 20 to 200 mg L -1 ) as well as 

suitable limit of detection (6 mg L -1 ). Moreover, if needed, these limits can be easily 

lowered by increasing the time of extraction, which in this case was less than 5 minutes. 

Acknowledgments: LMG (SFRH/BD/36791/2007) and JGP (SFRH/BD/30279/2006) wish to 

acknowledge Portuguese Fundação para a Ciência e Tecnologia (F CT) for their PhD studentships. 

References 

[1] Gonçalves, L.M.; Anunciação, M.F., Valente, I.M., Pacheco, J.G.; Magalhães, P.J.; Rodrigues, 

J.A.; Barros, A.A. Collection of Czechoslovak Chemical Communications. Accepted manuscript 

[1] Pacheco, J.G.; Valente, I.M.; Gonçalves, L.M.; Magalhães, P.J.; Rodrigues, J.A.; Barros, A.A. 

Talanta. 2010, 81, 372 

[3] Gonçalves, L.M.; Pacheco, J.G.; Magalhães, P.J.; Rodrigues, J.A.; Barros, A.A. Food Additives 

and Contaminants. 2010, 27, 175 



 

activity. Gallic acid interference 

Maria J.F. Rebelo, Dulce M.A. Gil 

CCMM -Faculdade de Ciências da Universidade de Lisboa, Campo Grande, C 8 

1749-016 Lisboa, Portugal, 

mjrebelo@fc.ul.pt 

It is, nowadays, common knowledge that wines contain polyphenols, which make them 

 

polyphen 

 

which had a good correlation to the antioxidant activity of several Portuguese wines, 

measured by the ABTS assay, r = 0.9795 (p < 0.05). 

 

Folin-Ciocalteu assay, which takes gallic acid as reference, most of the times. So, we 

studied the influence of gallic acid in enzymatic assays in more detail. The interaction of 

gallic acid in free (with UV-Vis spectrophotometric detection) and immobilized (with 

amperometric biosensor detection) Laccase enzyme oxidation of caffeic acid is 

presented. IC 50, was determined to be 19.15 ± 0.11 µM and 5.11 ± 0.19 µM for free and 

immobilized enzyme, respectively. The gallic acid study was complemented with cyclic 

voltammetry of separate and mixed solutions of caffeic and gallic acid, at bare or 

covered by membranes with immobilized laccase glassy carbon electrodes and will be 

presented. 

Aknowledgements: D.M.A Gil acknowledges F CT (Fundação para a Ciência e a Tecnologia) for a 

Ph.D. fellowship (SFRH/BD/34511/2006). The authors acknowledge Financial support from 

Faculdade de Ciências da Universidade de Lisboa 



An electrochemical biosensor for toxic amides determination: 

Merits and Limitations 

Nelson A. F. Silva 1 , Manuel J. Matos 1 , Amin Karmali 1 , Maria Manuela Rocha 2 

1 CIEQB-ISEL - Instituto Superior de Engenharia de Lisboa, Portugal 

2 DQB Faculdade de Ciências da Universidade de Lisboa, Portugal 

nsilva@deq.isel.ipl.pt 

The present work reports some experimental results concerning an investigation that is 

presently being conducted in order to develop and implement an electrochemical 

biosensor for toxic amides determination [1]. 

The biological recognition element consists of whole cells of Pseudomonas aeruginosa 

containing intracellular amidase activity, which catalyses the hydrolysis of amides, such 

as acrylamide, producing ammonium ions and acrylic acid. 

The transduction process is provided by an ammonium ion selective electrode. 

Whole cells were firstly immobilized in several types of polymeric membranes, such as 

polyethersulfone, nitrocellulose, polycarbonate or nylon, which were attached to the 

surface of the transductor according to different procedures. The reaction time was 6 

minutes. These biosensors, typically, exhibited a linear response in the range of 

10 -4 -10 -1 mol.L -1 of acrylamide, a detection limit in the order of 10 -4 mol.L-1 of 

acrylamide, and a sensitivity of 48.0 mV/decade. Other figures of merit such as, 

selectivity, correlation coefficient, response time or half life time, concerning the 

ility, were also investigated. 

 

example, the time needed for complete removal of ammonium ions from the vicinity of 

the transducer, after the catalytic reaction, so that each assay could start with identical 

conditions, was about 45 minutes. This period of time is not compatible with continuous 

measurements or even environmental monitoring of acrylamide. 

In order to overcome this limitation, some investigation studies are being conducted 

regarding the development and optimization of other immobilization matrices for whole 

cells of Pseudomonas aeruginosa. Some main characteristics of these matrices, such as, 

high substrate and product diffusion rates, easy removal of ammonium ions after each 

assay; biochemical compatibility with the biological recognition element and 

mechanical stability, should be accomplished. 

Glutaraldehyde, bovine serum albumin (BSA), gelatin, nafion, agarose, zeolites, sol-gel 

technology, alginates beds, and other immobilization agents and procedures, have been 

used and combined, to prepare several different immobilization matrices. [refs!] 

The results that we will present, bearing in mind the characteristics mentioned above, 

range from poor to frankly good. 

In future we hope to be able to use this biosensor for acrylamide and other toxic amides 

determination in food and environmental samples. 

References 

[1] Silva, N.; Gil, D.; Karmali, A.; Matos, M.; Biocat Biotransf, 2009, 27, 143. 



Construction of a nitrite biosensor based on the direct 

electrochemistry of a multihemic nitrite reductase on carbon 

nanotube modified electrodes 

Célia M. Silveira 1 , Marta Pimpão 1 , Fernando Pereira 2 , José J.G. Moura 1 , 

M. Gabriela Almeida 1 

1 

REQUIMTE Departamento de Química, CQFB, Faculdade de Ciências e Tecnologia, 

Universidade Nova de Lisboa, 2829-516 Caparica, Portugal 

2 

LCM Laboratório de Catálise e Materiais, DEQ - Faculdade de Engenharia da Universidade do 

Porto, R. Dr. Roberto Frias, 4200-465 Porto, Portugal 

celia.silveira@dq.fct.unl.pt 

In recent years, biosensors have been an intense research field, as they constitute 

advantageous alternatives to conventional analytical methods. The electrochemical 

enzyme based devices are of particular interest due to their operational simplicity, low 

cost fabrication, portability and real-time monitoring capability. The devices based on 

direct electron transfer between the electrode and the redox enzyme represent the most 

attractive and simple approach. However, several issues still challenge the direct 

electrochemistry of proteins. As so, the development of appropriate electrodes and 

protein immobilization methods to enhance the direct electron exchange while retaining 

biological activity is crucial. In this regard, the modification of electrode surfaces at a 

molecular scale using carbon nanotubes (CNTs) has become increasingly popular. CNT 

deposits on solid supports generate three dimensional porous structures that greatly 

enlarge electrode surfaces. As a result we can obtain higher loadings of proteins on 

electrodes and achieve optimal distances to their redox centers. The efficiency of 

heterogeneous electron transfer and bioelectrocatalysis is thus markedly improved [1-3]. 

This work reports the use carbon nanotubes to promote the direct electrochemistry of the 

multihemic nitrite reductase (ccNiR) from Desulfovibrio desulfuricans ATCC 27774. 

Multi-walled (MWCNT) CNTs were used to modify the surface of pyrolytic graphite 

electrodes (PGEs). A layer-by-layer deposition method was used, in which drops of 

CNTs dispersions are successively applied on the electrode, followed by the addition of 

enzyme. Dispersions were prepared in water, organic solvents and detergents. The 

catalytic response to nitrite was considerably improved in the presence of the carbon 

nanotubes when compared to plain electrodes modified with enzyme only. The 

electrocatalytic characteristics of the bioelectrodes responses were compared and 

evaluated in terms of the structural and chemical properties of the different CNTs. The 

analytical performance of the bioelectrodes will also be presented and discussed. 

Acknowledgments: C.M. Silveira thanks the financial support funded by Fundação para a Ciência 

e Tecnologia (SFRH/BD/28921/2006). 

References 

[1] J.J. Davis, K.S. Coleman, B.R. Azamian, C.B. Bagshaw, M.L. Green, Chem. Eur. J. 9 (2003) 

3732. 

[2] J.J. Gooding, R. Wibowo, J. Liu, W. Yang, D. Losic, S. Orbons, F.J. Mearns, J.G. Shapter, D. 

B. Hibbert, J. Am. Chem. Soc. 125 (2003) 9006. 

[3] K. Gong, Y. Yan, M. Zhang, L. Su, S. Xiong, L. Mao, Anal. Sci. 21 (2005) 1383. 



Polymeric chemiresitive sensors for wood classification 

Renata Lippi, Jonas Gruber, Juliana R. Cordeiro, Erica S. Takahashi, 

Rosamaria W. C. Li 

Instituto de Química, Universidade de São Paulo, SP, Brasil 

Renata.Lippi@poli.usp.br 

An electronic nose [1] capable of identifying two pairs of wood species: (a) mahogany 

and cedar (Figure 1) and (b) Brazilian walnut and black-cinnamon was developed. The 

electronic nose consists of four gas sensors, fabricated by the deposition of thin doped 

conjugated polymer films onto the surface of interdigitated electrodes. The electrical 

conductance of these electrodes was measured during exposure to the volatile 

compounds of wood samples. Treatment of these data by principal component analysis 

and by cluster analysis gave excellent separation between the data sets. Leave-one-out 

analysis [2] presented a rate of hits of 100% in 80 identification assays carried out 

randomly with the above-cited species. Sets of electrodes have been tested for over six 

months and are still operational. The cost of each electrode is less than US$ 10. The 

equipment is portable and has low power consumption; hence, it can be used by police 

officers on the roads for the inspection of lorries carrying woods. 

Figure 1. PCA plot for mahogany and cedar 

Acknowledgments: to CNPq for the grants and financial support. 

References 

[1] Gardner, J. W.; Bartlett, P. N. Electronic Noses Principles and Applications, 1999, Oxford 

University Press. N.Y. 

[2] Lopes, F. M.; Martins-Jr, D. C.; Cesar-Jr, R. M. BMC Bioinformatics, 2008, 9, 451. 



Water soluble phthalate determination from bottled and 

coolers water by using Square Wave Voltammetric(SW V) 

technique 

Munawar Saeed Qureshi, Sirajuddin 

National Centre of Excellence in Analytical Chemistry University of Sindh, Jamshoro 76080, 

Pakistan. 

munwar_saeed@yahoo.com 

Phthalic acid esters (dialkyl or alkyl aryl esters) known as phthalates are 

commonly used as plasticizers in the polymer industry. Phthalates are widely used as 

additives in nail polish, printer inks, insecticides, toys, PVC, lubricants, food wraps, 

blood bags, catheters, etc. Phthalates are not chemically bound to the polymers and can 

diffuse out of the plastic and leach into the environment. The interest about phthalate 

esters is growing due their significant use and potential toxicity. Hence an efficient 

analytical method is needed for assaying of phthalates in various polymer products 

essential for safe monitoring of phthalates[1-4]. 

In our present study, a fast, simple and highly sensitive Square Wave 

Voltammetric (SWV) method was developed for evaluation of total water soluble 

phthalates by taking 95% aqueous di-n-butyl phthalate (DBP) as a model at glassy 

carbon electrode (GCE). The study showed that 100 µM aqueous solution of DBP gives 

best response with 0.05 M Tetra butyl ammonium bromide (TBAB), at stirring rate of 

1400 rpm, deposition time, 20 s and pH value, 4.0±0.1. The optimum frequency and 

scan rate was 100 Hz and 0.9 V/s respectively. SW Voltammetric response was linear in 

3 ranges, 70110 µM, 2060 µM and 210 µM with regression coefficient of 0.9873, 

0.9978 and 0.9935 respectively and limit of detection (LOD), 0.47 µM for total water 

soluble phthalates in aqueous medium. Under the same conditions Differential Pulse 

Voltammetry (DPV) gave a linear range of 0.5 4.5 µM with R value of 0.999 and 

detection limit of 0.05 µM. The developed method was successfully applied for total 

phthalates determination in various samples of water stored in PVC coolers and plastic 

bottles. The validity of the result was checked with reported method and good 

agreement was noticed between them. 

-40.0u 

I (A) 

-30.0u 

-20.0u 

-10.0u 

-1.20 -1.30 -1.40 -1.50 -1.60 -1.70 -1.80 

U (V) 

(V) 

Fig.1 - SW voltammograms of triplicate water sample from PVC cooler (Eagle Star) 

References 

[1] L. Guiseppe, V.D. Antonio, M. Marika, V. Alberto, F.D. Claudio, Toxicology, 2006, 226, 90. 

[2] X. Zhiyong, E. Ralf, T. Christin, L. Rainer, C. Armando, R. Wolfgan, Environ. Sci, Technol. 

2007, 41, 4555. 

[3] B.Tamar, C.H. Drorit, C.M. Antonia, N.L. Calafat, A.Yona, W. Uri, R. Elhu, Envir. Int, 2009, 

35, 353. 

[4] E. Makoto, M. Emiko, K. Kunio, Rep. Toxicol, 2000, 14, 13. 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society O C 01 

Electrosynthesis and Redox Conversion of 

Poly(3,4-ethilenedioxythiophene) Films An Ellipsometric 

and Probe Beam Deflection Study 

A. I. Melato, J. P. Correia, L. M. Abrantes 

CQB, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 

Campo Grande, 1749-016 Lisboa, Portugal 

aimelato@fc.ul.pt 

Poly(3,4-ethilenedioxythiophene) (PEDOTh) has been the subject of intense research 

devoted to the influence of the electropolymerization conditions on the films properties 

[1-3]. Despite the valuable data gathered by purely electrochemical techniques on the 

charge transfer processes during the synthesis and redox conversion of the polymers, 

they are unable to provide insights about the structural features of the films and on the 

nature of the species involved in the redox processes. Such information can be achieved 

by the powerful association of optical techniques with the electrochemical ones. In-situ 

Ellipsometry and Probe Beam Deflection (PBD) have been successfully employed to 

evaluate the dielectric properties and mass fluxes taking place both during the formation 

and electrochemical conversion of several conducting polymers [4-6]. 

In this work an ellipsometric and PBD study of the electrosynthesis and redox behaviour 

of PEDOTh films is presented. Thin polymeric films were generated on platinum 

electrodes, from organic solutions of the monomer, under potentiostatic and 

potentiodynamic modes, being electrochemically characterized by cyclic voltammetry. 

A two-homogeneous phase model has proven to be appropriate to describe the films 

optical properties and the mathematical tool of temporal convolution was employed to 

determine the extent and nature of each individual participation for the overall mass 

transfer. The combined electrochemical and optical information, collected for films 

prepared with distinct growth charges and in different supporting electrolytes, allowed 

to discuss the values of the local dielectric properties of the polymer and their relation 

with the mass transfer phenomena taking place during the PEDOTh formation and in the 

course of the doping/undoping processes. 

References 

[1] Melato, A. I.; Mendonça, M. H.; Abrantes, L. M. J. Solid State Electrochem. 2009, 13, 417. 

[2] Aubert, P.-H.; Groenendaal, L.; Louwet, F.; Lutsen, L.; Vanderzande, D.; Zotti, G. Synth. 

Metals 2002, 126, 193. 

[3] Niu, L.; Kvarnström, C.; Ivaska, A. J. Electroanal. Chem. 2004, 569, 151. 

[4] Correia, J. P.; Vieil, E.; Abrantes, L. M. J. Electroanal. Chem. 2004, 573, 299. 

[5] Abrantes, L. M.; Correia, J. P. Electrochim. Acta 1999, 44, 1901. 

[6] Melato, A. I.; Correia, J. P.; Abrantes, L. M. J. Electroanal. Chem., 

doi:10.1016/j.jelechem.2010.02.025. 



Convolutive modelling with Mathematica ® using Oldham- 

Mahon-Myland h i (t) functions. C r E q mechanism in C V. 

M. J. Barrera-Niebla 1 , M.J. González Morín 1 , M. R. García Hernández 2 , 

D.M. Grandoso Medina 1 , L.C. Fernández Mérida 1 

1 Physical Chemistry Department. University of La Laguna. La Laguna. 2 Consejería de Presidencia, 

Justicia y Seguridad. Gobierno de Canarias.TENERIFE. CANARY ISLANDS. SPAIN. 

mbarnie@ull.es 

Convolutive Modelling is an important methodology of Semiintegral and Convolution 

Electrochemistry [1]. We model with Mathematica ® software, in order to overcome the 

advanced mathematics, the I E curves for a C r Eq 

mechanism at planar electrodes. 

The mentioned methodology employs the universal convolution algorithm of Oldham 

and the extended semiintegrals M R (t) 

and M P (t) 

. The mechanism represented by 

k 

k 

f 

 

 

 

S( 

soln) 

 

R( 

soln) 

R( 

soln) 

ne P( 

soln) 

(1) 

k' 

kb 

allows us to infer for k k' 

the following expression for h R (t) 

, namely 

 

2k 

k' 

1 

2exp ( k k') 

t 

h R ( t) 

 

2( k k') 

t 

 

 

 

2 

 

2 k t 

k' 

exp 

 

k k' 

 

 

 

Erfi 

3/ 2 

( k k') 

 

 

 

k' 

t 

 

Erfi 

k k' 

 

k t 

 

 

k k' 

 

 

required to calculate, with Mathematica ® , the single integral of equation (2) needed in 

the convolutive modelling. When k k' 

an easier equation is obtained.. These 

methodologies let us to obtain the files: M R (t) 

, M P (t) 

, and in duplicate, I (E) 

. A very 

basic program written for Mathematica ® is reported to model I E curves. We check 

these files with those obtained by convolutive modelling with Oldham-Mahon-Myland 

g(t) 

functions and by digital simulation with DigiSim ® and DigiElch ® . This comparison 

was made with the assistance of SigmaPlot ® software. The agreement is excellent. The 

methodologies employed are based in the following convolutions 

dh t 

I t M t i ( ) 

( ) i ( )* i R, 

P 

(3) 

dt 

The extended semiintegrals M R (t) 

and M P (t) 

are connected with electrode surface 

concentrations by a linear relation with known parameters. Hence the C R ( 0, t) 

and 

C P ( 0, t) 

files are obtained in a straightforward procedure and are complementary with 

the concentration profiles C R ( x, 

1 t ) and C P ( x, 

1 t ) determined by digital simulation. 

(2) 

Acknowledgements: To Professor Keith B. Oldham, Peter J. Mahon and Jan C. Myland. 

References 

[1] Barrera-Niebla, M.J.. Semiintegral and Convolution Electrochemistry. Research line. 

Department of Physical Chemistry. (2010). La Laguna University. Tenerife. Canary Islands. 



Electro-oxidation of alcohols on Pd-Ag alloys 

in alkaline medium 

C ristina Oliveira, Rosa Rego 

Departamento de Química, Centro de Química - Vila Real, Universidade de Trás-os-Montes e Alto 

Douro, Apartado 1013, 5001-801 Vila Real 

mcris@utad.pt 

A new research era on direct alcohol fuel cells (DAFC) is emerging with the 

recent development of alkaline membranes. For decades, the development of new 

electrode materials for polymer electrolyte membrane fuel cells (PEMFC) concerned 

almost exclusively their behaviour in acid media. However, since the appearance of 

alkaline membranes, electrocatalysis studies are turning towards the alkaline media. As 

a consequence, alkaline direct alcohol fuel cells are coming out as an alternative to 

conventional acid direct alcohol fuel cells. 

In the last years, several works have shown that in alkaline media, Pd and Pdbased 

catalysts may display higher poison tolerance and higher activity than Pt based 

catalysts towards alcohol oxidation reaction, especially for ethanol oxidation reaction 

(EOR) [1]. Despite some studies have shown that Pd alloys may display even higher 

catalytic activity towards EOR than pure Pd, examples of these materials are still scarce 

and restricted to Au-Pd, Pd-Pb, Pd-Pt and Pd-Ni alloys [2-5]. 

In this work Pd-Ag alloys containing different amounts of Ag are prepared and 

characterized by XRD and SEM/EDS and their activities towards the electro-oxidation 

of alcohols in alkaline media is evaluated and compared to Pd and Pt. 

References 

[1] - C. Bianchini and P. Shen, Chem. Rev. 2009, 109, 41834206. 

[2]- M.Nie, H. Tang, Z.Wei, S. Jiang, P. Shen, Electrochem. Communicat. 2007, 9, 23752379. 

[3]- Y. Wanga, T. Nguyena, X. Liub, X.Wanga Journal of Power Sources 2010, 195, 26192622. 

[4]- S.Y. Shen, T.S. Zhao, J.B. Xu, Y.S. Li, Journal of Power Sources 2010,195, 10011006. 

[5]- J. Lua, S.Lua, D.Wanga, M.Yanga, Z. Liub, C.ei Xub, S. Jianga, Electrochim. Acta 2009, 54, 

54865491. 



Versatile surface functionalization of gold surfaces based on 

CS 2 -amine reaction 

I. Almeida, A. S. Viana 

Centro de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Ed. C8, 


ibalmeida@fc.ul.pt 

Numerous strategies have been developed in the preparation of biosensing surfaces, 

where the biological activity of the biomolecule is not compromised during and upon the 

immobilisation to the transduction surface. Self-assembled monolayers (SAMs) provide 

a simple route to modify electrode surfaces by organic molecules containing free anchor 

groups such as organosulphur derivatives. The monolayers are in general very stable, 

organized and packed allowing tremendous flexibility depending upon their terminal 

functionality, being suitable platforms for biosensing [1]. Recently, Dithiocarbamates 

(DTCs) have been used as an alternative to thiolated SAMs and implicated as important 

gold nanoparticles-binding groups in molecular electronics, due to their bidentate 

resonance structure involving N-C-S 2 [2]. DTCs may be formed readily in situ by the 

combination of secondary amines and CS 2 in the presence of gold substrates [3]. 

The main purpose of this work is to study by electrochemical methods the reactivity 

between carbon disulphide and several amines, including direct enzyme immobilisation 

onto gold surfaces. Different methodologies were used for gold functionalisation, 

namely: one-step DTCs formation onto gold (substrate in contact with a mixture of CS 2 

and amines); DTCs formation in solution followed by exposure to the gold surface; and 

finally, CS 2 self-assembling and post-reaction with amine-compounds. The redox 

behaviour of modified electrodes with electroactive compounds containing primary and 

secondary amines clearly revealed their covalent immobilisation on gold and allowed to 

estimate their surface concentration. Electrochemical reductive desorption of the 

anchored sulphur derivatives from gold provide further evidence for surface 

modification. The reaction of CS 2 and enzymes has been demonstrated for Glucose 

Oxidase. Chronoamperometric assays in the presence of glucose have confirmed 

biomolecule immobilisation and catalytic activity. Scanning Probe techniques (STM, 

AFM) were also used to characterize the morphology of the modified electrodes. 

Acknowledgments: The authors acknowledge to Dr. António Cascalheira for helpful discussion, V. 

C. Ferreira for the synthesis of gold nanoparticles and Fundação para a Ciência e a Tecnologia 

for funding (PTDC/QUI/66612/2006). 

References 

[1] Li M., Gao F.; Yang P.; Wang L.; Fang B. Surf. Sci., 2008,602, 151 

[2] Long D. P.; Troisi A. J. Am. Chem. Soc., 2007, 129, 15303 

[3] Zhu H.; Coleman D. M.; Dehen C. J.; Geisler I. M.; Zemlyanov D.; Chmielewski J.; Simpson 

G. J.; Wei A. Langmuir, 2008, 24, 8660 



Convolutive modelling with universal master equation of 

Oldham-Mahon-Myland by using Mathematica ® software. 

E q C i mechanism in C V at spherical electrodes. 

M. J. Barrera-Niebla 1 , M. R. García Hernández 2 , M. J. González Morín 1 , 

L.C. Fernández Mérida 1 , D.M. Grandoso Medina 1 

1 Physical Chemistry Department. University of La Laguna. La Laguna 

2 Consejería de Presidencia, Justicia y Seguridad. Gobierno de Canarias 

TENERIFE. CANARY ISLANDS. SPAIN. 

mbarnie@ull.es 

Convolutive Modelling is an important methodology of Semiintegral and Convolution 

Electrochemistry [1]. We model with Mathematica ® software, to overcome the advanced 

mathematics, I E curves for E q C i mechanism at spherical electrodes. The mechanism 

represented by 

k f 

 

 

k 

S( so ln) ne P( 

so ln) P( 

so ln) Q( 

so ln) 

(1) 

kb 

allows us to infer the following expressions for S (t) 

and P (t) 

, namely 

S( 

t) 

 

1 1 DSt 

 

 

exp 

erfc 

DSt 

a 2 

a 

 

P( 

t) 

exp 

kt 

 

 

Figure 1. Modelled 

voltammograms. 

DSt 

 

 

 

a 

1 1 D t 

exp P 

erfc 

DPt 

a 2 

a 

a electrode radius 

D 

 

Pt 

 

a 

required to apply the algorithm used to implement the master equation. A very basic 

program written for Mathematica ® is reported to model I E curves. We check, with 

SigmaPlot , these files with those obtained by digital simulation with DigiElch ® . 

The next figure display the comparison 

between convolutive modelling and digital 

simulation. The agreement is excellent. The 

60 

40 

20 

0 

-20 

-40 

-60 

-80 

-100 

-120 

10 6 I/A 

E/V 

-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 

(2) 

parameters employed were: T 298. 15K 

; 

a 10 3 

9 

2 1 

m ; 

DS DP 

10 

m s ; 

3 

CS b 1mol 

m 

0. 5 

0 4 

1 

k 10 

m s ; 

E reverse 0. 5V ; 

(3) 

; n 1 

; 

k 1s 

1 ; 

0 

E 0. 0V 

; 

1 

v 1V 

s ; t reverse 1s 

; 

3 

( sampling time) 

10 

s . DigiSim ® results 

also agree with previous files. 

Acknowledgements: To Professor Keith B. Oldham, Peter J. Mahon and Jan C. Myland. 

References 

[1] Barrera-Niebla, M.J.; Semiintegral and Convolution Electrochemistry. Research line. 

Department of Physical Chemistry. (2010). La Laguna University. Tenerife. Canary Islands. 



Electrocrystallisation of (Perylene) 2 [M(mnt) 2 ] salts 

Mónica Afonso, 1 Manuel J. Matos, 2,3 Rafaela A. L. Silva, 1 Quirina Ferreira, 2 

Manuel Almeida 1 

1 Dept. Chemistry, ITN / CFMCUL Estrada Nacional 10, P-2686-953 Sacavém, Portugal 

2 

IT, Av. Rovisco Pais, 1049-001 Lisboa, Portugal, 

3 ISEL, Av. Emídio Navarro, 1959-007 Lisboa, Portugal 

mafonso@itn.pt 

The charge transfer salts based on perylene (Per) and transition metal 

bis-maleonitrile-dithiolate M(mnt) 2 with different transition metals M and general 

formula, (Per) 2 [M(mnt) 2 ] have attracted continued interest for more than 30 years due to 

unique properties derived from the existence in the same solid of two types of chains: 

conducting chains of partially oxidized perylene molecules (Per) 1/2+ and chains of 

monoanionic complexes [M(mnt) 2 ] - that depending on the metal can be either 

diamagnetic (M=Cu, Au, Co) or paramagnetic (M=Ni, Pd, Pt, Fe). The mutual 

interaction between the two type of chains, both subject to lattice instabilities typical of 

one-dimensional conducting and magnetic systems, leads to a very rich and 

unprecedented variety of physical phenomena [1,2]. However the study of these 

compounds has been always limited by difficulties in the growth of good quality single 

crystals. The situation is further complicated by the fact that the crystals can be obtained 

in two polymorphs, e.g. in M=Cu, Ni [3] and Pt [4] and different stoichiometries are 

possible for M=Co [1]. 

These salts have been obtained mainly by electrocrystallisation; a solution of perylene 

and salts of [M(mnt) 2 ] - is submitted to electrochemical oxidation which generates 

perylene cations to give insoluble crystals of the (Perylene) 2 M(mnt) 2 compounds 

growing on the anode. This electrochemical method has advantages over chemical 

oxidation routes yielding better quality crystals, but has also strong limitations. 

In this communication we report the results of our systematic investigation aiming at to 

establish the best conditions for the growth of single crystals of the (Per) 2 M(mnt) 2 

compounds by electrocrystallisation that is constrained by the rather low solubility of 

perylene in appropriated solvents and the instability of the perylene radical cation. The 

conditions which allowed for the first time the preparation of (Per) 2 [Pd(mnt) 2 ] by 

electrocrystallisation are described. AFM and STM microscopy were used to monitor 

the early stages of crystal growth on different electrodes. The nucleation is found to 

occur preferentially at edge dislocations of HOPG and to be oriented along Au and Pt 

crystallographic axis. 

Acknowledgments: Work supported by F CT under contract PTDC/QUI-QUI/101788/2008. 

References 

[1] Almeida M. and Henriques R. T., in Organic Conductive Molecules and Polymers, H. S. Nalwa 

ed., vol. 1, chapter 2, pp. 87-149, John Wiley 1997. 

[2] Brooks, J.S., Graf, E.S.; Almeida, M.; R.T.; Matos, M. et al.; J. Low Temp. Phys., 2006, 142, 787. 

[3] Gama, V.; Almeida, M.; Henriques, R.T.; Santos, I.C.; et al. J. Phys. Chem., 1991, 95, 4263. 

[4] Henriques, R.T.; Sousa, I.; Almeida, M.; et al.; J. Low Temp. Physics, 2006, 142, 405. 



Application of the Scanning Electrochemical Microscope to 

study the corrosion mechanism in thin organic coatings with 

defects 

Andreia Marques, Alda Simões 

ICEMS/ DEQB, Instituto Superior Técnico, Technical University of Lisbon - TULisbon, Portugal 

alda.simoes@ist.utl.pt 

Corrosion resistance of steel sheet is greatly increased when metallic and organic 

coatings are applied together. In recent decades this concept was extended to coilcoating 

or pre-painted metal sheet, which is of special interest for the automotive 

industry. On the other hand, coil-coatings are difficult to weld, prone to cut-edge 

corrosion and the shaping process may introduce micro-defects. Hence, the development 

of coatings combining weldability and corrosion protection originated from self-healing 

of damaged areas is of special interest. 

Electrogalvanized steel sheet coil-coated with a 1.8µm weldable primer was choosen as 

an object of study. Electrical conductivity is assured by graphite particles dispersed in 

the polymeric matrix. 

To understand the corrosion mechanisms in thin conductive coatings and the 

mechanistic of self-repair of induced micro-defects of different sizes, samples were 

tested in 0.05M NaCl solutions. The Scanning Electrochemical Microscope (SECM) 

was used to study the localized corrosion kinetics of the thin protective coating at the 

defect area. These studies were compared to data obtained from electrochemical 

impedance spectroscopy. 

The SECM ultra microelectrode (UME) was used for amperometric measurements, at a 

constant cathodic potential of -0.70 V vs SCE. When the probe was located above the 

defect, very low current densities were measured at the UME. At this potential, currents 

correspond essentially to O 2 reduction. These results reveal local depletion of oxygen in 

solution, thus corresponding to an active cathodic area. Thus, a map of surface reactivity 

was obtained with good spatial resolution. 

Impedance spectroscopy revealed the activity of the coating is low when compared to 

metal-rich primers, probably because its conductive particles are graphite instead of 

metal particles. This explains why the impedance remains practically constant with time. 

Acknowledgments: The research was funded under contract RF CS-CT-2008-00028. 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society O D 01 

Quasi-simultaneous localised measurements of current density 

and ion distribution (pH, Cl - , Na + ) 

Svetlana V. Lamaka 1 , M. G. Taryba 1 , F. Montemor 1 , H. S. Isaacs 2 , 

M. G. S. Ferreira 1,3 

1 ICEMS, Instituto Superior Técnico, UTL, Av. Rovisco Pais 1049-001 Lisbon, Portugal 

2 Brookhaven National Laboratory, Upton, NY 11973, USA 

3 CICECO, Dep.Ceramics and Glass Eng., University of Aveiro, 3810-193, Aveiro, Portugal 

sviatlana.lamaka@ist.utl.pt 

Scanning vibrating electrode technique (SVET) measures the potential differences 

in solution due to the ionic flux produced above the sample surface during 

electrochemical corrosion as it flows from anode to cathode. The measured potential 

difference is converted to an electrical current density (µA/cm ) at the point of 

measurement. SVET is widely used as a powerful electrochemical technique for 

corrosion related studies. However, corrosion processes involve not only oxidationreduction 

reactions but also acid-base interactions. Acid-base equilibria can be studied 

by several localized electrochemical techniques in potentiometric mode, for example 

SECM and SIET. The same applies for determination of Cl - that plays a crucial role in 

the ionic equilibria at the surface of corroding metals. 

Scanning ion-selective electrode technique (SIET) works as a micro-potentiometric 

tool allowing measurements of specific ions over the active surface in solution. The size 

of the measuring tip of the ion-selective microelectrode is around 2 micron. SIET and 

SVET provide valuable and complementary information. Sequential use of both 

techniques was demonstrated by several groups in the field of corrosion [1-4]. 

The presentation will describe SVET and SIET measurements undertaken 

simultaneously with a time lag 1.5 to 4 seconds. The combined SVET-SIET 

measurements correlate electrochemical oxidation-reduction processes with acid-base 

chemical equilibria. Simultaneously rather than sequentially measured distribution of 

specific ions and current density provides a higher quality of local data that can be used 

for modelling and prediction of corrosion. 

Acknowledgments: The support by Fundação para a Ciência e a Tecnologia (F CT, Portugal) 

- 

LA-2008-214261is gratefully acknowledged. 

References 

[1] Ding, H.; Hihara, L.H. J.Electrochem.Soc. 2005, 152, B161. 

[2] Ogle, K.; Morel, S.; Jacquet, D. J.Electrochem.Soc. 2006, 153, B1. 

[3] Lamaka, S.V.; Karavai, O.V.; Bastos, A.C.; Zheludkevich, M.L.; Ferreira, M.G.S. 

Electrochem.Commun. 2008, 10, 259. 

[4] Bastos, A.C.; Taryba, M.G.; Karavai, O.V.; Zheludkevich, M.L.; Lamaka, S.V.; Ferreira, 

M.G.S. Electrochem.Commun. 2010, 12, 394. 



Water Uptake Estimation in O rganic Coatings using 

Electrochemical Impedance Spectroscopy 

R. G. Duarte, 1,2 A. S. Castela, M. G. Ferreira 

1 

Instituto Superior Técnico, Chemical and Biological Eng. Dept/ICEMS, Av. Rovisco Pais, 

1049-001 Lisbon, Portugal. 

b 

Escola Superior de Tecnologia do Barreiro/ IPS, 2830-144 Barreiro, Portugal. 

raquel.duarte@estbarreiro.ips.pt 

The water uptake in organic coating films can be estimated by EIS and, for this purpose, 

several models can be found in the literature [1,2,3]. 

The EIS method for the determination of the water uptake parameter presents several 

practical advantages compared with the more traditional ones, namely gravimetry, such 

as: it is a non destructive test, it can be used in every substrate and it can be applied in 

situ. These factors led to a wider use of such technique for the study of this parameter. 

In this presentation water uptake in PVC Plastisol films was estimate by EIS using 

models referred in the literature. The gravimetry technique was also used as a reference 

method. The influence of the salt concentration and ions type in the outer solution were 

also taken into consideration. 

In this study it was concluded that water uptake values estimated by EIS are influenced 

by the outer solution parameters, presenting higher values for films immersed in 

solutions containing cations with lower hydrated diameter and also for the more 

concentrated solutions. It was also verified that anions presented in the outer solution do 

not influence the water uptake values estimated by this technique. Likewise the film 

resistance is also influenced by the outer solution characteristics. however, the resistance 

evolution was opposite to the one determined for the water uptake. 

The gravimetric technique showed quite opposite results, in which the water uptake did 

not change with the cation characteristics and presented higher values for the solutions 

with lower concentration. 

Comparison between the water uptake values obtained by the EIS models and the ones 

obtained by gravimetry was also performed . 

References 

[1] D. M Brasher, A. H. Kingsbury, J. Appl. Chem., 1954 , 4, 62. 

[2] A. S. Castela, A. M. Simões, Corr. Sci., 2003, 45, 1647 

[3] R. G. Duarte, A. S. Castela, M. G. S. Ferreira, Prog. Org. Coat, 2009, 65, 197 



Novel electrochemical techniques for classical corrosion 

problems: the Scanning Vibrating Electrode applied to 

galvanized steel cut edges 

Alda Simões 

ICEMS & DEQB / Instituto Superior Técnico/ TULisbon 

Av. Rovisco Pais, 1049-001 Lisboa, Portugal 

alda.simoes@ist.utl.pt 

Space-resolved electrochemical techniques have recently been gaining grounds for 

development in corrosion studies. They are based upon micro-electrodes and of a nonintrusive 

approach, allowing scanning and mapping of a chosen property along an active 

surface. The scanning vibrating electrode technique (SVET) is particularly useful for 

peculiar systems like cut edges of coil-coated steel, which combine close contact 

between anode and cathode with very thin electrodes, resulting in high gradients of pH 

and ion concentration and generating severe limitations to the classical techniques. The 

SVET has good characteristics for this system and has been successfully applied to cut 

edges [1-4]. The study deals with the potentialities of space-resolved techniques for such 

a system and with the effect of corrosion inhibitors in solution on the current values and 

distribution. The conclusions are supported by other techniques, namely 

potentiodynamic polarization and electrochemical impedance spectroscopy. Mapping of 

the ionic currents reveals that the cathode shifts away from the anode as zinc corrosion 

products precipitate at the location of the peak cathodic current. The presence of 

different inhibitors leads to different results, depending on the efficiency and 

mechanism. Sodium phosphate inhibits corrosion at the cut edge by precipitation of zinc 

phosphate clusters with barrier properties, whereas benzotriazole can under some 

circumstances cause loss of cathodic protection. 

Acknowledgements: The collaborations of Juliana Custódio and of Dr. João Fernandes are greatly 

acknowledged. The research was partly sponsored by the European Research Fund for Coal and 

Steel (contract RFS-CR-04021). 

References: 

[1] F.Zou, H.S.Isaacs, D.Thierry, Corrosion Science, 2000, 42, 1149. 

[2] K. Ogle, S. Morel and J.Jacquet, J.Electrochem. Soc., 2006, 153(1), B1. 

[3] A.M. Simões, J. Torres, R. Picciochi, J.C.S. Fernandes, Electrochim. Acta 2009, 54, 3857. 

[4] J.V. Custódio, S.M.L. Agostinho, A.M.P. Simões, Electrochim. Acta 2010, doi:10.1016/ 

j.electacta.2010.03.072. 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society O E 01 

Electrochemistry of Push-Pull compounds based on 

Quinoline-N-Oxide 

C. Capel Ferrón a,b , B. Vercelli b , G. Zotti b , 

J. M. Montenegro c , E. Pérez Inestrosa c , V. Hernández a , J. T. López Navarrete a 

a 

Department of Physical Chemistry, Málaga University, 29071 Málaga (Spain) 

b 

Institute for Energetics and Interphases-IENI CNR, C.so Stati Uniti, 4, 35127 Padova (Italy) 

c 

Department of Organic Chemistry, Málaga University, 29071 Málaga (Spain) 

capel@uma.es 

Dipolar push-pull chromophores are currently the subject of great interest for their use in 

photonic devices and represent the widest class of organic compounds investigated for 

their nonlinear optical (NLO) properties [1] and rectifying behaviour in molecular 

electronics. [2] 

Push-pull NLO systems are basically constituted by an electron-donor (D) and an 

electron-acceptor (A) group interacting though a -conjugated spacer (S) (D-S-A 

molecules). These systems constitute the way to achieve an efficient charge 

redistribution from the donor to the acceptor end groups. 

Here we consider a series of D-S-A molecules based on quinoline-N-oxide (A) moieties 

The UV-Vis absorption spectra in acetonitrile of 1-3 upon addition of acid (HClO 4 ) 

increase in intensity and maxima are largely batochromically shifted, due to protonation 

of the N-oxide moiety which increases its acceptor ability. Further addition of HClO 4 to 

solutions of 2 and 3 causes a subsequent hypsochromic shift due to the protonation of 

the methoxy or dimethylamino electron-donor groups. 

The reduction potential of aromatic N-oxides is known to be strongly pH-dependent, 

reduction being facilitated under acidic conditions and the protonated N-oxide becoming 

a much better electron acceptor. In this regard, we have investigated the 

electrochemistry of both the neutral and protonated forms of all these D-S-A 

chromophores, together with the complexation of 3 with a Lewis acid like zinc chloride. 

References 

[1] Prasad, P. N.; Wiliams, D. J. Introduction to Nonlinear Optical Effects in MolecVles and 

Polymers; Wiley: New York, 1991 

[2] (a) Geoffrey J. Ashwell,* Wayne D. Tyrrell, Anne J. Whittam, J.Am.Chem. Soc. 2004, 126, 

7102; (b) Geoffrey J. Ashwell, Anna Chwialkowska, Chem. Commun., 2006, 1404. 



Electrochemical, Thermodynamic and K inetic Studies of the 

Acylated Cyanoimido-Complexes 

trans- Mo(N C N){N C N C(O)R}(dppe) 2 Cl 

Elisabete C.B.A. Alegria, a,b M. Fátima C. Guedes da Silva, b,c Maxim L. 

Kuznetsov, b Luísa M.D.R.S. Martins, a,b Armando J.L. Pombeiro b 

a Área Departamental de Engenharia Química, ISEL, R. Conselheiro Emídio Navarro, 

1959-007 Lisbon, Portugal 

b Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco 

Pais, 1049001 Lisbon, Portugal 

c Universidade Lusófona de Humanidades e Tecnologias, ULHT Lisbon, Av. do Campo Grande, 

376, 1749-024 Lisbon, Portugal 

ebastos@deq.isel.ipl.pt 

The electrochemical behaviour of the complexes trans- 

Mo(NCN){NCNC(O)R}(dppe) 2 Cl (R = Me, Et and Ph) (denoted by A + ) has been 

investigated by cyclic voltammetry (CV) and controlled potential electrolysis (CPE) in 

aprotic medium, at a Pt electrode. These complexes exhibit, apart from a partially 

reversible oxidation attributed to the Mo(IV) to Mo(V) oxidation, a first partially 

reversible reduction (A + to A 0 ) process which involves a electron-transfer-induced 

rearrangement according to the indicated ECEC square-type Scheme (Figure). Digital 

simulation of the cyclic voltammetric data, at a range of scan rates, allows to estimate 

the corresponding equilibrium and rate constants. Theoretical calculations were also 

performed on attempting to identify the electrochemically generated species B. 

A + 

e 

A 

k2 

K 1 = k 1 / k -1 

k-2 

k -1 k 1 

K 2 = k 2 / k -2 

B + 

- e 

B 

Acknowledgments: This work has been partially supported by the IPL/41/2003 project, the 

Fundação para a Ciência e Tecnologia (F CT), the POCTI (F EDER funded) and the PRODEP 

programmes. 

References 

1 S.M.P.R.M. Cunha, M.F.C. Guedes da Silva, A.J.L. Pombeiro, J. Chem. Soc., Dalton Trans., 

2002, 1791 

2 A.J.L. Pombeiro, M.F.C. Guedes da Silva, M.A.N.D.A. Lemos, Coord. Chem Rev., 2001, 219. 

[3] M.L. Kuznetsov, A.J.L. Pombeiro, J. Chem. Soc., Dalton Trans., 2003, 738. 



Potentiometric Determination of Copper with a New 

Selective Electrode 

Maximilian N. Kopylovich, a K amran T. Mahmudov, a Matti Haukka, b 

Konstantin V. Luzyanin, a Armando J. L. Pombeiro a 

a Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, 

Av. Rovisco Pais, 1049001 Lisbon, Portugal 

b University of Joensuu, Department of Chemistry, P.O. Box 111, FIN-80101, Joensuu, Finland 

kamran_chem@mail.ru 

A new azoderivative of benzoylacetone, namely 1-phenyl-2-(2- 

hydroxyphenylhydrazo)butane-1,3-dione (H 2 L), was synthesized and shown to exist in 

solution as a mixture of enol-azo and hydrazo tautomeric forms, the latter being 

promoted by a decrease in temperature and an increase in solvent polarity. A copper(II) 

complex with H 2 L was isolated in the solid state and found to be the polymer [Cu 2 (- 

L) 2 ] n with a binuclear core. The dissociation constants of H 2 L (pK 1 =5.98±0.04, 

pK 2 =9.72±0.03) and the stability constants of its copper(II) complex (log 1 =11.010.07, 

log 2 =20.190.08) were determined. 

A new copper-selective PVC membrane electrode with H 2 L as a carrier was 

elaborated and its composition was optimized. This electrode has a detection limit of 

6.30×10 M Cu(II) at pH 4.0 with response time 10 s and displays a linear EMF vs. 

log[Cu 2+ ] response over the concentration range 2.0×10 M Cu(II) with a 

0, and good 

selectivity over a wide range of metal ions (e.g. Na + , K + , Ba 2+ , Ca 2+ , Zn 2+ , Cd 2+ , Co 2+ , 

Mn 2+ , Ni 2+ , Fe 2+ , Al 3+ ). The proposed sensor shows better characteristics than most of 

its, response time and 

selectivity over other metal ions. 

A procedure for the determination of copper(II) in zinc, aluminum and nickel 

based alloys was also developed showing its high selectivity, sensitivity and 

reproducibility. Thus, the established method can be used in routine determination of 

copper in a diversity of objects with environmental, biological, medical or industrial 

significance without need for preconcentration or pretreatment. 

Acknowledgements: This work has been partially supported by the Foundation for Science and 

 

References 

[1] Z. Bazooka, Analyst, 1988, 113, 1803. 

[2] A. Abbaspur, M.A. Kamyabi, Anal. Chim. Acta, 2002, 455, 225. 

[3] L.P. Singh, J.M. Bhatnagar, Talanta 64, 2004, 313. 



Redox Properties of Cu(I) Camphor Hydrazone Complexes 

M. Fernanda N.N. Carvalho, Tiago. A. Fernandes, Adelino M. Galvão 

CQE, Complexo I, Instituto Superior Técnico, Technical University of Lisbon, 

Av. Rovisco Pais 1049-001 Lisboa, Portugal 

fcarvalho@ist.utl.pt 

Aiming at get an insight into the redox properties of Cu(I) camphor hydrazone 

compounds we studied the electrochemical behavior of the one-dimensional 

coordination polymers [{CuX} 2 (YNC 10 H 14 O)] n (X=Cl: Y=NMe 2 1a; Y=NHMe 1b, 

Y=NH 2 1c; X=Br: Y=NH 2 2c) [1] and dimers [Cu(YNC 10 H 14 -X)] (X=Cl: Y=NMe 2 

3a; Y=NHMe 3b; X=Br: Y=NMe 2 4a; Y=NHMe 4b) [2] by cyclic voltammetry and 

controlled potential electrolysis (CPE). 

As a general trend the camphor hydrazone Cu(I) complexes display one cathodic and 

one anodic processes (Table 1). The cathodic processes occur at potential values in the 

range of the corresponding free ligand suggesting a ligand based process. 

Table 1 - Cyclic voltammetry data a for complexes [{CuX} 2 (YNC 10 H 14 O)] n and [Cu(YNC 10 H 14 -X)] 

E ½ red (V) 

E ½ ox (V) 

X Y Polymer Dimer Polymer Dimer 

Cl NMe 2 -2,04 -2,07 0.61 0.60 

Cl NHMe -2.12 b, d -2.18 b,d 0.58 0.62 

Cl NH 2 

c 

0.63 

Br NMe 2 -2,09 0.65 

Br NHMe -2.23 b,d 0.67 

Br NH 2 -1,96 d 0.62 

a 

Pt wire as electrode and [NBu 4 ](BF 4 ] (0.2M) in THF using as electrolyte. Values measured in Volt (± 10 mV). b 

Irreversible wave. c Not observed within the potential range available. d Another cathodic wave is observed at 

lower potential. 

The anodic processes are metal based involving transfer of two electrons per mole in the 

dimer species. CPE performed at the potential of the anodic process in coordination 

polymers is masked by chemical reactivity. 

Acknowledgments: To Fundação para a Ciência e Tecnologia (F CT) for financial support to 

Project PPCDT 58119/QUI/2004 and a PhD grant to T.A. Fernandes (SFRH/BD/48331/2008). 

References 

[1] M.F.N.N. Carvalho, T.A. Fernandes, A.M. Galvão, H.-A. Krug von Nidda, M.A.P. Sampaio, 

Inorganica Chimica Acta, 2010, 363, 7176. 

[2] M.F.N.N. Carvalho, M.T. Duarte, T.A. Fernandes, A.M. Galvão, A. M. Botelho do Rego, 

unpublished work. 



Poster Communications 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society PA 01 

Nickel Speciation in the Xylem Sap of the Hyperaccumulator 

Alyssum serpyllifolium ssp. lusitanicum G rowing on Serpentine 

Soils of Northeast Portugal 

Sheila Alves 1 , Cristina Nabais 2 , Maria de Lurdes Simões Gonçalves 1 , 

Margarida M. Correia dos Santos 1 

1 Centro de Química Estrutural, IST, Av. Rovisco Pais, 1049-001, Lisboa, Portugal. 

2 Centro de Ecologia Funcional, FCT, Universidade de Coimbra, 3000 Coimbra, Portugal 

sheila@ist.utl.pt 

Due to the dynamic nature of voltammetric methods, it is possible to have knowledge on 

the kinetics of the interconversion of the species present in solution and also to obtain 

information regarding the concentration of those species [1]. As previously reported, 

Square Wave (SW) and Cyclic Voltammetry proved to be efficient tools in a speciation 

study of Ni in the xylem sap of Quercus ilex, vulgar holly oak [2,3]. 

In this work SW Voltammetry was used to provide a model for Ni speciation in the 

xylem sap of Alyssum serpyllifolium Desf. ssp. lusitanicum Dudley & Silva, a Nihyperaccumulator 

endemic to the serpentine soils of northeast Portugal. 

The xylem sap was collected from plants growing in its native habitat and characterized 

in terms of Ni, Ca and Mg content using Flame atomic Absorption Spectrometry [4] and 

carboxylic and amino acids content using Reverse Phase High Performance Liquid 

Chromatography with Diode Array Detection (RP-HPLC-DAD) [5]. 

Thereafter Ni speciation was study in model and 

real solutions of xylem sap by SW voltammetric 

titrations at 0.10 M ionic strength and pH = 7.0 

(figure 1). 

The results showed that Ni transport in the xylem 

sap occurs mostly as a free hydrated cation 

(about 70%). Citric acid is the main Ni 

complexing ligand (18% of total Ni). Oxalic, 

aspartic, malic and malonic acids complexes 

account for approximately 5, 4, 2 and 2% of total 

Ni, respectively. The coordination to other amino 

acids is negligible [5]. 

Acknowledgments: This work was co-financed by 

POCI 2010 and by the European Social Fund. Sheila 50 

Alves acknowledges F CT for PhD Grant SFRH/BD/21597/2005. 

[Ni] Free 10 6 M 

Figure 1. SW voltammograms of the titration 

of A. serpyllifolium ssp. lusitanicum xylem 

sap diluted solution with nickel 

E / V vs. Ag/AgCl 

-1.5 -1.3 -1.1 -0.9 

40 

50 

References 

[Ni] 

0 

[1] Mota A.M.; Correia dos Santos M.M. In: Metal Speciation 30 

0 and 50 Bioavailability 100 150 in Aquatic 

[Ni] t, 10 6 M 

Systems (eds: Turner D.; Tessier A.), Wiley, 1995, pp. 205-258. [2] Correia dos Santos, M.M.; 

20 

Santos, M.M.; Alves, S.; Simões Gonçalves, M.L. Electroanalysis, 2007, 19, 2351. [4] Alves, S.; 

10 

Gonçalves, M.L.S.; Correia dos Santos, M.M. Phytochemical Analysis, 2009, 20, 365. [5] Alves, B 

[Ni] Free 10 

6 M 

A 

Incre 

asin 

Alves, S.; Simões Gonçalves, M.L.; Nabais C. Electroanalysis, 2006, 18, 814. [3] Correia dos 

S.; Nabais C.; Gonçalves, M.L.S.; Correia dos Santos, M.M. Submitted for publication. 

150 

100 

g 

0 

-20 

-40 

-60 

-80 

-100 

-120 

-140 

0 

0 10 20 30 40 50 

[Ni] t , 10 6 M 

I / nA 



Electrodegradation of 4-aminonaphtalene-1-sulfonic acid with 

BDD and Ti/Pt/PbO 2 Anodes 

A.S. Rodrigues, M.J. Pacheco, L. Ciríaco, A. Lopes 


asfrodrigues@hotmail.com 

Naphthalene sulfonic amines are very toxic pollutants released to the environment in the 

effluents of several industries, especially in the textile industry. Many of this type of 

pollutants are biorefractory and electrochemical processes, such as anodic oxidation 

using anodes with high oxygen overpotential, like boron doped diamond (BDD) and 

Ti/Pt/PbO 2 , have become an alternative method to achieve their degradation [1]. Both 

anodes have high oxidation power and are able to generate highly reactive physisorbed 

hydroxyl radicals. 

The aim of this work was to study the performance of the above mentioned anodes, 

BDD and Ti/Pt/PbO 2 , in the anodic oxidation of 4-aminonaphtalene-1-sulfonic acid, 

using as supporting electrolyte two different salts: NaCl and Na 2 SO 4 . 

Ti/Pt/PbO 2 electrodes, with geometric area of 10 cm 2 , were prepared by thermal 

electrochemical method [2]. The BDD electrode was purchased from Adamant 

Technologies/CSEM. The electrochemical assays were performed in galvanostatic 

mode, at 300 A m -2 imposed current density. The electrochemical assays were run in an 

electrochemical cell, with a BDD or Ti/Pt/PbO 2 anode, working in batch mode. 

Degradation of 4-aminonaphtalene-1-sulfonic acid was followed by UV-VIS 

spectrophotometry, Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) 

determinations. 

When the performance of both anode materials is compared, in the tests run with NaCl 

as electrolyte, it can be concluded that the mineralization is always higher for the BDD 

anode, since after 6 h assay TOC removal was 61% for this electrode and 21% for the 

Ti/Pt/PbO 2 . However, in what concerns COD removals, the difference between the 

 

BDD and 90% for those performed with Ti/Pt/PbO 2 . 

The analysis of data obtained with chlorides suggest that COD removal occurs in the 

first hours of electrolysis, while, with sulfates, removal occurs gradually throughout the 

test. In spite of this different behavior, the final COD removal, after 6 h, is only slightly 

dependent on the electrolyte. 

Acknowledgments: The financial support of Fundação para a Ciência e a Tecnologia, F CT, BII- 

12/UMTP/UBI/2009. 

References 

[1] Ciríaco L.; Anjo C.; Correia J.; Pacheco M.J.; Lopes A. Electrochimica Acta, 2009, 54, 1464. 

[2] Andrade L.S.; Rutuolo L.A.M.; Rocha-Filho R.C.; Bocchi N.; Biaggio S.R.; Iniesta J.; Garcia- 

Garcia V.; Montiel V. Chemosphere, 2007, 66, 2035. 



Influence of hydrodynamic conditions on the anodic 

degradation of phenol on BDD 

S. Sobreira, L. Ciríaco, M.J. Pacheco, A. Lopes 


analopes@ubi.pt 

The anodic oxidation of effluents containing organic pollutants is an alternative that has 

received great attention in the last years due to its interesting characteristics, since it is a 

clean process, can operate at low temperature and, in most cases, without adding any 

reagent and without sludge formation. Recently, an important development in these 

processes took place with the use of boron-doped diamond (BDD) as anode material for 

the oxidation of all kind of organic pollutants [1]. 

The objective of this work was to study the influence of hydrodynamic conditions on the 

mass transfer process during the anodic oxidation of a model compound, phenol, using 

BDD as anode material. 

The electrochemical assays were performed in galvanostatic mode, at an imposed 

current density of 100 A m -2 . Two sets of electrochemical assays were run, using two 

different experimental set-ups: an electrochemical cell, with a BDD anode of 17.5 cm 2 

area, working in batch mode, at several stirring rates, and a DiaCel 196PVDF, with two 

monopol BDD electrodes, with 70 cm 2 area, working in batch with re-circulation mode, 

at several different flow rates. Degradation of phenol was followed by Chemical Oxygen 

Demand (COD) determinations, Total Organic Carbon (TOC) tests and UV-VIS 

spectrophotometry measurements. The experimental results have demonstrated that an 

increase in the stirring rate or in the recirculation flow rate leads to an increase in the 

COD, TOC and absorbance removal rates. 

The obtained results have shown that the turbulence near the electrode surface is a 

very important parameter and its control can be used to increase the degradation rate, 

with equal energy consumption, thus decreasing energetic costs for the anodic oxidation 

of organic pollutants. 

Acknowledgments: The financial support of Fundação para a Ciência e a Tecnologia, F CT, 

PDCT/AMB/59392/2004, and Adamant Technologies are gratefully acknowledged. 

References 

[1] Panizza M.; Cerisola G. Electrochim. Acta, 2005, 51, 191. 



Recuperação de Metais em Solução 

C. Ascensão, L. Ciríaco, M.J. Pacheco, A. Lopes 

UMTP e Departamento de Química, Universidade da Beira Interior 

lciriaco@ubi.pt 

A aplicação de técnicas electroquímicas na área do ambiente é cada vez mais uma 

realidade. Estas técnicas apresentam uma grande versatilidade e podem ser aplicadas na 

remoção de poluentes sólidos, líquidos e gasosos. 

Uma das classes de poluentes mais perigosos é a dos metais pesados. Existem vários 

métodos para a sua separação e/ou recuperação, alguns usando a combinação de várias 

técnicas como processos de membranas, electrólise ou precipitação, podendo os iões 

metálicos serem recuperados no estado metálico ou na forma de óxidos ou hidróxidos, 

para posteriormente serem reutilizados, recuperando assim o seu valor comercial. 

Muitos iões metálicos em solução podem ser recuperados na forma metálica por redução 

num cátodo sob condições específicas, sendo exemplos a prata e o cobre, cujo valor 

económico é significativo, e o cádmio e o chumbo, cuja toxicidade é elevada [1] e que 

são usados em pilhas comuns e baterias de automóveis. Outros metais, como o níquel e 

o crómio, são geralmente recuperados por precipitação dos respectivos hidróxidos. O 

chumbo pode ser facilmente recuperado electroquimicamente, tanto na forma metálica, 

sobre o cátodo, como na forma de óxido, sobre o ânodo [2], ambos produtos úteis. 

Pretende-se, neste trabalho, concentrar os metais existentes em amostras multicomponentes 

e, se possível, reduzi-los electroquimicamente à forma metálica ou 

precipitá-los na forma de hidróxidos. Na primeira parte deste estudo foram realizadas 

reduções de alguns iões metálicos partindo de soluções modelo, contendo um ou vários 

metais. Estudou-se a redução de Cu 2+ , Cd 2+ , Pb 2+ e Zn 2+ , determinando-se a 

percentagem de recuperação do metal consoante o potencial aplicado, quer por 

determinação da massa depositada sobre os eléctrodos quer por medidas da 

concentração do metal em solução ao longo dos ensaios, recorrendo à análise das 

soluções por espectroscopia de absorção atómica. Usaram-se soluções de sulfatos e/ou 

cloretos dos metais acidificadas a pH 3,5, aplicando-se diferentes potenciais durante 3 h. 

Os ensaios foram realizados numa célula de um compartimento, com uma placa de aço a 

funcionar como cátodo, entre 2 placas de platina, que funcionavam como ânodo, e o 

eléctrodo de Ag/AgCl,KClsat, como eléctrodo de referência. Para o chumbo realizaramse 

também ensaios em células de 2 compartimentos. Os melhores resultados de 

recuperação dos metais para as condições estudadas foram: Cu 2+ 99,5 % a E= 0,1 V; 

Cd 2+ 89,8 % a E= 0,8 V; Pb 2+ 99,6 % a E= 0,8 V e Zn 2+ 37,0 % a E= 1,3 V. 

Agradecimentos: Fundação para a Ciência e a Tecnologia, F CT, PTDC/CTM/64856/2006 e 

PTDC/AAC-AMB/103112/2008 

Referências 

[1] Doulakas, L.; Novy K.; Stucki, S.;Comninellis, Ch. Electrochimica Acta, 2000, 46, 349. 

[2] Brandon, N.P.; Pilone D.; Kelsall, G.H.; Yin, Q. Journal of Applied Electrochemistry, 2003, 33, 

853. 



The effects of lithium, potassium and cesium ions on 

the diffusion behaviour of caffeine in aqueous solutions 

Victor M.M. Lobo 1 , Cecilia I.A.V. Santos 2 , Miguel A. Esteso 2 , Marisa C.F. 

Barros 1 , Ana C.F. Ribeiro 1 

1 Department of Chemistry, University of Coimbra, 3004 - 535 Coimbra, Portugal 

vlobo@ci.uc.pt 

Caffeine is naturally occurring in some beverages and is also used as a 

pharmacological agent which is a central nervous system stimulant [1-3]. The 

interactions of metal ions with caffeine (3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6- 

dione) are of major biological interest, due to the fact these complexes play a dominant 

role in many biochemical interactions [1-3]. Currently, diffusion coefficients of caffeine 

[4] in aqueous solutions and their dependence on media composition (e.g., pH, ionic 

strength and metal ions) have been poorly characterized, even though these transport 

parameters are necessary to obtain a satisfactory understanding of the tumor/drug 

interactions. 

H 3C 

O 

N 

H 3C 

N 

N 

O 

N 

CH 3 

Figure 1 caffeine 

The present communication intends to be a contribution in filling this gap. In this 

work, we present ternary diffusion coefficients D 11 , D 22 , D 12 and D 21 for the ternary 

systems (potassium chloride/caffeine, lithium chloride/caffeine, and caesium 

chloride/caffeine), for the range of concentrations of each component between 0.0001 M 

and 0.010 M at 298.15 K, using a specially designed apparatus built for experimentally 

measuring diffusion coefficients based on the Taylor technique. Comparing the main 

coefficients D 11 and D 22 and the binary diffusion coefficients of each component, and 

using the values of cross coefficients D 12 and D 21 , we can take conclusions about the 

influence of the caffeine solutes in diffusion of these salts. Also from the ratios D 21 /D 11 

and D 12 / D 22, it is possible to obtain information concerning the number of moles of each 

component transported per mole of the other component driven by its own concentration 

gradient. We believe that our results will provide guidance for a better understanding of 

the physicochemical behavior of these important pharmaceutical systems in aqueous 

solutions. 

Acknowledgments: We are also grateful to Prof. Pierandrea Lo Nostro from the Department of 

Chemistry of University Firenze, Italy, for his valuable help of the interpretation on the diffusion 

coefficients of these 3 component systems. 

References 

[1] Nafisi, S.; Shamloo, D. S.; Mohajerani, N.; Omidi, A.J. Mol. Struct. 2002, 608, 1. 

[2] Nafisi, S.; Monajemi, M.; Ebrahimi, S. J. Mol. Struct. 2004, 705, 35. 

[3] Food Chem. 2004, 84, 383. 

[4] Ribeiro, A. C. F.; Santos, C. I. A. V.; Lobo, V. M. M.; Cabral, A. M. T. D. P. V.; Veiga, F. J. 

B.; Esteso, M. A.J. Chem. Eng. Data 2009, 54, 115. 



Improving electrocatalityc activity of LaNiO 3 coatings by 

deposition on foam nickel substrates 

C.O. Soares 1 , M. D. Carvalho 1 , M.E. Melo Jorge 1 , A. Gomes 1 , R.A.Silva 2 , 

C.M. Rangel 2 , M.I. da Silva Pereira 1 

1 C.C.M.M., Departamento de Química e Bioquímica da Faculdade de Ciências da 

Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal 

2 Laboratório Nacional de Energia e Geologia, Paço do Lumiar 22, 

Fuel Cells and Hydrogen Unit, 1649-038 Lisboa, Portugal 

cybelle_oliveira@hotmail.com 

Search for new or improved electrode materials is restless in the field of power sources, 

namely of batteries and fuel cells. One of the challenging problems in the area is to find 

an effective electrode material that operates alternatively as anode and cathode and 

catalyses the oxygen electrochemical reactions (bifunctional oxygen electrode) [1]. 

Perovskite type oxide materials are considered potential candidates since they present 

high electrochemical stability, in strong alkaline solutions, and can catalyse oxygen 

evolution and reduction, simultaneously. 

In this work LaNiO 3 oxide was prepared by a self-combustion method using citric acid. 

The electrodes were prepared by coating a nickel foam support with an oxide suspension 

followed by a heat-treatment. Electrochemical characterization was carried out by cyclic 

voltammetry. The electrodes electrocatalytic activity, towards the oxygen evolution 

reaction (OER) in alkaline medium, has been evaluated by steady state measurements. 

The OER follows a first order kinetics, with respect to OH - concentration, with Tafel 

slopes close to 60 and 120 mV for low and high overpotentials, respectively. These 

values are in accordance with those referred in the literature [2]. On the other hand the 

recorded apparent current densities are higher than those usually reported for the same 

oxide material. This result indicates that the increase on the electrode activity is mostly 

related to geometric factors, what can be associated with a high electrode/electrolyte 

contact area provided by the foam nickel substrate, what is in accordance with the 

roughness factor of 3463±250 estimated for the oxide coating. 

Acknowledgements: This work is partially financed by Fundação para a Ciência e Tecnologia 

(F CT), under contract nº PTDC/CTM/102545/2008 

References 

[1] Jorissen, L. J. Power Sources, 2006, 155, 23. 

[2]Singh, R. N.; Tiwari, S. K.; Sharma T.; Chartier P.; Koenig J. F. J New Mat for Electrochem 

Systems, 1999, 2, 65. 



Electrochemical treatment of the dye C.I. Reactive Yellow 

138:1 in a filter press reactor 

Ana Isabel del Río, Enrique Duval, Mª José Benimeli, Javier Molina, José 

Bonastre, Francisco Cases 

1 Departamento de Ingeniería Textil y Papelera, EPS de Alcoy, Universidad Politécnica de 

Valencia, Plaza Ferrándiz y Carbonell s/n, 03801 Alcoy, Spain 

delgaran@doctor.upv.es 

The electrochemical behaviour of C.I. Reactive Yellow 138:1 was investigated. This dye 

was used as a commercial sample of a bifunctional reactive dyes containing 

monochlorotriazinyl group as reactive group. It was selected because it is a 

representative bifunctional dye. In general, reactive dyes produce an unusable 

hydrolyzed form that can amount to as much as 15-40% of the total applied [1]. 

The concentration studied was 1.4 g L -1 . This value was selected because it corresponds 

to a typical dye concentration in a real wastewater. Besides, Na 2 SO 4 was employed as 

background electrolyte. The electrochemical treatment was carried out by means of 

oxido-reduction, oxidation and reduction processes in a filter press reactor at different 

current densities. Stainless steel was used as cathode and Ti/SnO 2 -Sb-Pt as anode. UV- 

Visible spectroscopy analyses revealed a complete decolourisation when oxidoreduction 

and oxidation were carried out. It is also important to highlight that the 

organic matter present in solution was not completely degraded since some bands were 

observed in the UV region after the electrochemical treatments. Moreover, HPLC 

technique was employed to monitor all the electrolyses and the decolourisation rate was 

established for all processes. The oxido-reduction processes decoloured the dye solution 

more quickly. In addition to this, it was demonstrated that all the electrochemical 

processes followed a pseudo-first order kinetic. For oxido-reduction and oxidation 

processes, COD removal was always higher than TOC removals. This implies the 

production of oxidised intermediate species that could not be completely degraded. 

From COD and TOC measurements, different parameters such as Average Oxidation 

State (AOS), Carbon Oxidation State (COS), Average Current Efficiency (ACE) and the 

ratio between the Average Current Efficiency and the initial value of COD (ACE/COD 0 ) 

were calculated. Finally, BOD 5 assays were done in order to evaluate the 

biodegradability of the dye solution after all the electrochemical treatments. 

Acknowledgments: Authors thank to the Spanish Ministerio de Ciencia y Tecnología and European 

Union Funds (F EDER) (contract CTM2007-66570-C02-02) and Universidad Politécnica de 

Valencia (Programa de apoyo a la investigación y desarrollo de la UPV (PAID-05-08)) for the 

financial support. J. Molina and A.I. del Río are grateful 

(Generalitat Valenciana) and the Spanish Ministerio de Ciencia y Tecnología respectively for the 

FPI fellowship. 

References 

[1] Allen R.L.M., Colour Chemistry. Nelson & Sons, London, 1971. 



Síntesis electroquímica de nanopartículas de plata y su 

potencial uso como agente antimicrobiano 

Felipe Hernández-Luis 1 , Mario V. Vázquez 2 , Lucas Blandón 2 , 

Gelmy Ciro 3 , Dora M. Benjumea 3 

1 Departamento de Química Física, Universidad de La Laguna, Tenerife, España 

2 Grupo de Electroquímica, Instituto de Química, Universidad de Antioquia, Medellín, Colombia 

3 Programa Ofidismo y Escorpionismo, Universidad de Antioquia, Medellín, Colombia 

ffhelu@ull.es 

Las nanopartículas de plata (AgNP), forman parte de las llamadas nanopartículas de 

metales nobles. Pueden ser usadas como agentes antibacterianos, como materiales 

criogénicos superconductores, o como biosensores, entre otras aplicaciones. La 

eficiencia de las AgNP en estas áreas está relacionada con el tamaño de partícula y con 

la morfología de las mismas. 

Generalmente, el tamaño y la morfología de las nanopartículas se controlan ajustando 

las condiciones de reacción según el método de síntesis utilizado [1]. Se han ensayado 

diversos métodos de fabricación de nanopartículas metálicas como por ejemplo: 

molienda mecánica, pirólisis por pulverización, precipitación química y deposición por 

vapor [2]. En los últimos años se han desarrollado nuevos métodos de síntesis que 

utilizan reductores fuertes, descomposición térmica, ablación por láser, irradiación con 

microondas, síntesis sonoquímica y métodos electroquímicos. Para la síntesis 

electroquímica pueden emplearse distintas vías de preparación [3-4]. 

La aplicación de nanopartículas de plata, como agentes de inhibición del crecimiento 

antimicrobiano, ha sido ensayada con distintas especies de acuerdo a lo reportado en 

varias publicaciones recientes [5]. 

En este trabajo se presentan algunos resultados preliminares obtenidos con 

nanopartículas sintetizadas electroquímicamente, utilizando distintas condiciones 

experimentales. El análisis de tamaño de partícula muestra una distribución bastante 

buena, aunque susceptible de ser mejorada variando algunos procedimientos 

experimentales. Estas nanopartículas fueron analizadas como inhibidoras del 

crecimiento de Pseudomona Aeruginosa y de Escherichia Coli, empleando el método 

propuesto por Abate y colbs. [6]. Los primeros resultados muestran una concentración 

mínima inhibitoria de 5 ppm de AgNP. 

References 

[1] Zhang, W.; Qiao, X; Chen, J. Mater. Sci. Eng., B, 2007, 142, 1. 

[2] Kurihara, L.K.; Chow, G.M.; Schoen, P.E. Nanostruct. Mater. 1995, 5, 607. 

[3] Starowics, M.; Stypula, B.; Banás.J. Electrochem. Commun. 2006, 8, 227. 

[4] Khaydarov, R.A.; Khaydarov, R.R.; Gapurova, O.; Estrin, Y.; Scheper, T. J. Nanopart. Res. 

2009, 11, 1193. 

[5] Sondi, I.; Salopek-Sondi, B. J. Colloid Interface Sci. 2004, 275, 177. 

[6] Abate, G; Mshana R.N.; Miorner, H.. Int. J. Tuberc. Lung. Dis. 1998, 2, 1011. 



- 

remediación de suelos contaminados 

Felipe Hernández-Luis 1 , Mario V. Vázquez 2 , Lucas Blandón 2 , 

Lina García 2 , Nedher Sánchez 2 

1 Departamento de Química Física, Universidad de La Laguna, Tenerife, España 

2 Grupo de Electroquímica, Instituto de Química, Universidad de Antioquia, Medellín, Colombia 

ffhelu@ull.es 

El problema de los suelos y las aguas contaminadas requiere el continuo desarrollo de 

nuevas metodologías adecuadas para eliminar distintos contaminantes. La conocida 

técnica electrocinética de remediación de suelos (electro-remediación o electrodescontaminación) 

ha sido aplicada para movilizar un gran número de contaminantes 

orgánicos e inorgánicos [1-2]. Esta técnica electrocinética consiste básicamente en la 

aplicación de un campo eléctrico entre dos electrodos inertes que se encuentran en 

contacto con un suelo húmedo. Este campo eléctrico da origen a una serie de fenómenos 

de transporte [3] que propician el movimiento de sustancias cargadas y no cargadas 

presentes en los suelos, entre los que se destacan la migración y el flujo electroosmótico. 

Para el tratamiento de aguas contaminadas, un método habitual es el empleo de 

materiales adsorbentes [4]. Debido a las grandes cantidades disponibles, a su bajo costo 

y a su elevada eficacia, los absorbentes más usados son aquellos constituidos por 

biomasa lignocelulósica [4]. Estos materiales han mostrado una buena capacidad de 

adsorción de contaminantes cuando son sometidos a un pre-tratamiento químico [5]. Un 

ejemplo de este tipo de adsorbentes es el aserrín obtenido de distintas especies 

forestales. Este adsorbente ha mostrado ser muy eficaz para retener colorantes presentes 

de aguas residuales [6]. 

En este trabajo se presentan algunos ensayos preliminares del tratamiento de un suelo 

contaminado con una disolución de colorante. Para ello se combina la técnica 

electrocinética de remediación con el método físico de adsorción. Con este propósito se 

emplea una célula convencional de electro-remediación a la que se le incorpora un 

 

electrodos se emplearon barras de grafito a las que se les aplicó un campo eléctrico 

constante de 24 V durante 48 h. El contaminante utilizado fue el colorante Rojo 

Reactivo 239, empleado habitualmente en la industria textil. Los resultados evidencian 

la posibilidad de movilizar dicho colorante desde el suelo para, posteriormente, 

inmovilizarlo sobre el tapón de aserrín. 

Referencias 

[1] Vazquez M.V.; Hernandez-Luis, F.; Lemus, M.; Arbelo C.D. Portugaliae Electrochimica Acta 

2004, 22, 387. 

[2] Reddy, K. R.; Chinthamreddy, S. Waste Manag. (Oxford) 1999, 19, 269. 

[3] Pomés, V.; Fernández A.; Houi, D. Trans IChemE 2002, 80, 256. 

[4] Sciban, M.; Radetic, B.; Kevresan, Z.; Klasnja, M. Bioresorse Technology 2007, 98, 407. 

[5] Larous S., Meniai H., Bencheikh M. Desalination 2005, 185, 483. 

[6] Sánchez, N., Tesis de Maestría, Universidad de Antioquia, 2010. 



Electric Dreams 

Clementina Teixeira, Maria da Conceição Oliveira, Erik C.P. Benedicto 

Centro de Química Estrutural, Departamento de Engenharia Química e Biológica do Instituto 

Superior Técnico 

clementina@ist.utl.pt 

Following the approach of chemical microscopy, a series of reduction-oxidation 

 

10 up to 126x 

enabled a better understanding of these reactions and were used to create decorative 

 

 

Figure 1. Growth of dendritic silver crystals from the reaction of copper with a silver 

nitrate 0.1 M solution. 

Figure 2. Growth of dendritic lead crystals from the reaction of zinc with lead nitrate 

0.1 M solution. 

Acknowledgments: Ciência Viva projects and MCT funding programs. 

References 

[1] Teixeira, C. Química, Boletim da Sociedade Portuguesa de Química, 2007, 107, 18. 



Determinación de conductividades y viscosidades del sistema 

(CoCl 2 + sacarosa +água) a temperatura de 298,15 K 

Damien O. Costa 1 , Ana C.F. Ribeiro 2 , Cecilia I.A.V. Santos 1 , Ana C. Santos 1 , 

Carmen Teijeiro 1 , Miguel A. Esteso 1* 

1 Departamento de Química Física, Universidad de Alcalá, 28871. Alcalá de Henares, Madrid, 

España 

2 Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal 

* autor para correspondencia, e-mail: miguel.esteso@uah.es 

Los hidratos de carbono y sus derivados son la fuente principal de energia 

alimenticia en todo el mundo. Entre ellos, los azúcares son los más utilizados para 

obtener energia para el funcionamiento corporal. Estos oligo-complejos, pueden afectar 

de forma significativa, la destrucióne de los dientes o restauraciónes dentales associadas 

presentes en la cavidad bucal. Los carbohidratos iran funcionar como substracto para las 

basterias produziren placa de acido, influenciando en la corrosión de las amalgamas. El 

cobalto, es un componente presente en muchas aleaciones utilizadas en estos 

restauraciones dentales que, por oxidación en el ambiente bucal agresivo, da lugar a la 

presencia en el medio de iones procendentes de este metal. Aunque la interacción entre 

carbohidratos y sus derivados y los iones metálicos há recebido particular atención, 

estudios de sus propriedades electroquímicas, como viscosidad y conductividad, seran 

necessários para entendermos mejor las interacciónes complejos-iónes en la corrosión 

ocurida en las amalgamas, sistemas para los que la informacion está en grand medida 

escasa o poco explorado. 

En esta comunicación se presentam medidas 

relativas a estas propriedades de transporte, viscosidad y 

conductividad, junto com valores de densidad, de 

disoluciones acuosas de cloruro de cobalto (en el rango de 

concentraciones molales compriendidas entre 0,0001 y 

0,1) en ausencia y presencia de sacarosa (concentraciones 

de azúcar < 0,03 molal), a la temperatura de 298,15 K. 

Estos datos han sido analizados en función de la fuerza 

iónica del medio, así como de la concentración del azúcar. 

Referencias 

1. F. Contu, B. Elsener, H. Ovni, Corrosion Sci. 47 (2005) 1863 

2. A. Ciszewski, M. Baraniaka, M. Urbanek-Brychczynska, Dental Mater. 23 (2007) 

1256 

3. A. C. F. Ribeiro, A. J. M. Valente, D. O. Costa, S. M. N. Simoes, R. F. P. Pereira, V. 

M. M. Lobo, M. A. Esteso, Electrochim. Acta 56 (2010) 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society PB 01 

Voltammetric Analysis of Sulphites in Alcoholic Beverages 

using Gas-Diffusion Microextraction 

Manuel P. C ruz, Inês M. Valente, Luís M. Gonçalves, 

João P. Pacheco, José A. Rodrigues, Aquiles A. Barros 

Requimte, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do 

Porto. Rua do Campo Alegre, n.º 687, 4169-007 Porto, Portugal 

jarodrig@fc.up.pt 

The purpose of this study was to develop a voltammetric methodology aiming sulphite 

determination using a hanging mercury drop electrode, based on prior extraction of 

sulfur dioxide (SO 2 ) by gas-diffusion microextraction (GDME). Sulphites are widely 

used as preservatives in the food industry for their several roles including the prevention 

of undesirable microbial growth and oxidation processes [1]. Square-wave voltammetry 

(SWV) is very advantageous in the determination of sulphites since there is a direct 

detection, i.e. it is the SO 2 molecule that is instrumentally measured in the electrode [2]. 

GDME is an innovative technique that combines the advantages of membrane aided gasdiffusion 

with microextraction concepts [3,4]. GDME makes uses of a novel portable 

and low-cost device that comprises a small, commercially available, semi-permeable 

membrane. Volatile compounds released by the sample can permeate the membrane 

pores and are collected by an adequate solution. Some of the advantages of this 

extraction system are: the experimental simplicity of the sample preparation process, the 

use of a disposable small sized membrane and the possibility of extraction of volatile 

compounds at low temperatures. The methodology is based on the sample acidulation 

transforming all sulphites into SO 2 that volatilizes and is collected, after passing through 

the membrane, by the existing solution within the extraction module. Such solution is 

acetate buffer in which there is a reaction of conversion of SO 2 into non volatile HSO 3 - . 

After a certain period of time, this solution is collected and analyzed by SWV. The 

results were compared with the method of Ripper (Portuguese Norm 2220). 

Acknowledgments: LMG (SFRH/BD/36791/2007) and JGP (SFRH/BD/30279/2006) wish to 

acknowledge Portuguese Fundação para a Ciência e Tecnologia (F CT) for their PhD studentships. 

References 

[1] Bird, D Understanding wine technology: The science of wine explained, The Wine Appreciation 

Guild, 4th ed., EUA, 2005 

[2] Almeida, P.J.; Rodrigues, J.A.; Guido, L.F.; Santos, J.R.; Barros, A.A.; Fogg, A.G. 

Electroanalysis, 2003, 15, 587 

[3] Rodrigues, J.A.; Gonçalves, L.M.; Pacheco, J.G.; Barros, A.A.; PT Patent 104789 (pending), 

2009 

[4] Gonçalves, L.M.; Magalhães, P.J.; Valente, I.M.; Pacheco, J.G.; Dostálek, P.; Sýkora, D.; 

Rodrigues, J.A.; Barros, A.A. Journal Chromatography A, In Press. 



Identificação de solventes voláteis por meio de nariz eletrônico 

de poli(sulfeto de fenileno-fenilenoamina) dopado 

eletroquimicamente 

Renata Lippi 1 , Fernanda F. Camilo 2 , Jonas Gruber 1 

1 

Instituto de Química da Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 

CEP 05508-900, São Paulo SP Brasil 

2 Universidade Federal de São Paulo Campus Diadema 

Renata.Lippi@poli.usp.br 

Três filmes finos de poli(sulfeto de fenileno-fenilenoamina), PPSA, um copolímero 

alternado de polianilina e poli(sulfeto de fenileno) [1], depositados por spin-coating 

sobre eletrodos interdigitados, obtidos por litografia, com área de 1 cm 2 (cromo sobre 

vidro; distância entre dígitos de 24 m) foram oxidados potenciostaticamente a 0,7, 0,8 

e 1,0 V vs. Ag em acetonitrila/LiClO4 0,1 M. 

A condutância elétrica desse conjunto de sensores foi monitorada durante períodos 

alternados de exposição (15 s) a vapores de oito solventes voláteis a 32 ºC e períodos de 

recuperação (ar puro, 60 s). A resposta relativa (R a ) de cada sensor foi calculada pela 

expressão R a = (G 2 -G 1 )/G 1 , em que G 2 é a condutância no fim do período de exposição e 

G 1 é a condutância inicial. A análise de componentes principais (PCA) das respostas 

relativas dos três sensores mostrou que esse conjunto consegue identificar os oito 

solventes (Figura 1). Análise do tipo leave-one-out [2] resultou num índice de acertos de 

100 %. 

Figura 1. Gráfico de PCA para os oitos solventes estudados. 

Agradecimentos: Ao CNPq pelo auxílio financeiro. Ao Dr. Gustavo P. Rehder pela confecção dos 

eletrodos. Ao Leonardo Ventura pelo desenvolvimento do equipamento eletrônico. 

Referências 

[1] Bazito née Camilo, F. F.; Torresi, S. I. C. Polymer, 2006, 46, 1259. 

[2] Lopes, F. M.; Martins-Jr, D. C.; Cesar-Jr, R. M. BMC Bioinformatics, 2008, 9, 451. 



Non-Usual Features of Haem Proteins at Pyrolytic G raphite 

Electrodes 

Patrícia M. Paes de Sousa, Sofia R. Pauleta, M. Lurdes Simões Gonçalves, 

Graham W. Pettigrew, Isabel Moura, José J. G. Moura, Margarida M. Correia 

dos Santos 

1 Requimte, Centro de Química Fina e Biotecnologia, Departamento de Química, Faculdade de 

Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal 

patricia.sousa@dq.fct.unl.pt 

Direct electrochemistry of redox proteins has been reported in an increasing number 

of cases, opening the way to thermodynamic and detailed mechanistic studies. To be 

successful, proteins must directly exchange electrons with the electrode and at the same 

time preserve their native properties [1]. Among the various types of electrode surfaces, 

pyrolytic graphite (PG) is extensively used, often in connection with protein film 

voltammetry [1]. In this useful strategy the proteins are adsorbed onto a freshly polished 

PG electrode, frequently just by painting the surface with a couple of micro litres of a 

concentrated protein sample. 

In this work, we show that the interaction of haem containing proteins with pyrolytic 

graphite electrodes induces altered forms of the proteins, which have a redox potential 

300 mV lower than the potential observed when analysed at other electrode surfaces 

[2,3]. Moreover, these altered forms present (electro)catalytic activity towards hydrogen 

peroxide. This effect had been previously proposed for small Met-His c-type 

cytochromes [4,5], but we demonstrate that this phenomenon is independent of the axial 

coordination of the haem, and is also observed for a multihaem enzyme. 

Therefore, the interpretation of the electrochemical signals obtained for haem 

containing proteins at this type of electrodes should be carefully done in order to avoid a 

misinterpretation of the results, especially when studying enzymes, in which the altered 

forms may present catalytic activity towards the same substrate. 

References 

[1] Léger, C.; Bertrand, P. Chem. Rev., 2008, 108, 2379. 

[2] Correia dos Santos, M. M.; Paes de Sousa, P. M.; Simões Gonçalves, M. L.; Krippahl, L.; 

Moura, J. J.G.; Lojou, É.; Bianco, P. J. Electroanal. Chem., 2003, 541, 153. 

[3] Santos, M.; Correia dos Santos, M. M.; Simões Gonçalves, M. L.; Costa, C.; Romão, J. C.; 

Moura, J. J. G. J. Inorg. Biochem., 2006, 100, 2009. 

[4] Ye, T.; Kaur, R.; Senguen, F. T.; Michel, L. V.; Bren, K. L.; Elliott, S. J. J. Am. Chem. Soc., 

2008, 130, 6682. 

[5] De Biase, P. M.; Paggi, D. A.; Doctorovich, F.; Hildebrandt, P.; Estrin, D. A.; Murgida, D. H.; 

Marti, M. A. J. Am. Chem. Soc., 2009, 131, 16248. 



Evaluation of Antioxidant Capacity by potentiostatic 

electrolyses 

Juliana Marques, Raquel Oliveira, Fátima Bento, Dulce Geraldo, Paula 

Bettencourt 

Departament of Chemistry, Universidade do Minho, 4710-057 

juliana.g.marques@hotmail.com 

There has been a growing interest in the study of antioxidant activity either for health 

purposes or for biotechnological applications, like in food preservation. 

Several methods have been proposed for evaluation of antioxidant capacity. However, 

there is a lack of a validated assay that can reliably measure the antioxidant capacity 

of foods and biological samples. In this scope it is recognized the importance of 

establishing an antioxidant activity scale by means of a standard method. Chemical 

methods commonly used for antioxidant characterization can be classified regarding 

their oxidation reaction mechanisms, involving a hydrogen atom transfer (HAT) or an 

electron transfer (ET) reaction. Most HAT-based assays monitor competitive reactions 

and the quantification is derived from the kinetic curves such as ORAC or TRAP 

assays, while the ET based assays involves the reduction of a specific oxidant (FRAP, 

ABTS + or DPPH). 

In this paper, we propose a methodology to evaluate antioxidant activity based on an 

electrochemical assay, which enables to classify antioxidants through their reducing 

power at fixed potentials. Diluted solutions of different antioxidants were electrolyzed 

via potentiostatic control, at different potentials. The antioxidant concentration decrease 

and the amount of charge used in the oxidation were determined. The amount of charge 

that the antioxidant is able to receive for a fixed conversion is used as a measure of the 

antioxidant capacity. In this study we compare the antioxidant power of known 

antioxidants like trolox and caffeic, ascorbic and gallic acids. 



Evaluation of gallic acid antioxidant activity based on its 

extensive oxidation promoted by electrochemical methods 

Raquel Oliveira, Juliana Marques, Fátima Bento, Dulce Geraldo, Paula 

Bettencourt 

Departament of Chemistry, Universidade do Minho, 4710-057 

juliana.g.marques@hotmail.com 

Cellular oxidative stress and oxidative degradation of foods are associated to the 

occurrence of oxidative processes on a large scale involving reactive oxygen species 

(ROS) such as O 2 , H 2 O 2 , O 2 •- and HO • . The promoted oxidation reactions may involve 

free radicals that start chain reactions, causing large scale destruction of molecules and 

biological systems (such as cells). The antioxidants action on the prevention of oxidative 

damage is widely recognized and is associated to their ability to remove free radicals 

and to inhibit the oxidation of other molecules through their own oxidation. 

The identification of the activity of recognized antioxidants or of new molecules is 

carried out by different methods, mostly chemical, which allow characterizing the 

reactions of these compounds with various reactive species. The use of synthetic radicals 

such as ABTS •+ (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate)), DPPH • (2,2- 

diphenyl-1-picrylhydrazyl) or DMPD •+ (N,N-dimethyl-p-phenylenediamine) is common 

in chemical assays despite their lack of meaning in biological or chemical natural 

samples. The generation of ROS is of fundamental importance in order to carry out 

relevant activity tests. 

Electrochemical methods, such as cyclic voltammetry have been extensively used to 

characterize antioxidants, through the estimation of their standard reduction potentials, 

E 0 . Despite the importance of this thermodynamic parameter, the kinetic 

characterization of reactions of antioxidants is crucial because it determines their ability 

to respond in time. 

In this paper, we present a study on the gallic acid response to a large scale oxidative 

attack promoted by electrochemical means. By adjusting the anode potential, the assay 

enables to test the antioxidant behavior against oxidants of different strength. This is an 

advantage toward chemical assays based on a chemical oxidant characterized by a fixed 

redox potential, E 0 . Another advantage of the electrochemical oxidative attack is the 

ease monitoring of the oxidation reaction rate, which is assessed directly from the 

current, in opposition to the chemical assays that require the direct monitoring of the 

oxidant or of a probe in a competitive assay. 

Acknowledgments: Fundação para a Ciência e a Tecnologia (SFRH/BD/64189/2009). 



Thiol monolayers on bismuth electrodes for organic matter 

fouling prevention in the voltammetric 

stripping analysis of heavy metals 

María de la Gala Morales, Eduardo Pinilla Gil, Lorenzo Calvo Blázquez 

Department of Analytical Chemistry, University of Extremadura, 

Av. de Elvas, s/n 06006 Badajoz, Spain 

mgalamor@gmail.com 

Stripping voltammetric measurements of heavy metals are frequently hampered by 

electrode fouling due to adsorption of organic compound naturally occurring in a variety 

of real samples (e.g. ambient and residual waters or biological fluids). A strategy to 

manage this problem is electrode protection by an isolating layer permeable to the small 

ionic analytes but not to the much larger interfering organic compounds. Disorganized 

monolayers of thiols with short alkyl chains and bulky end group have been proven 

useful for gold electrode protection against model surfactants [1] and humic acid [2]. 

Thiol monolayers deposition on bismuth electrodes, a widely used environmentally 

friendly alternative to mercury electrodes, has been studied and their general 

electrochemical behaviour described [3], but no data is available about the applicability 

of thiol protected bismuth electrodes for the determination of heavy metals in presence 

of organic surfactants. In this work, we have explored the voltammetric stripping 

behaviour of Zn(II), Cd(II) and Pb(II) on a homemade bismuth disk electrode before and 

after deposition of a disorganized monolayer of different thiols, using Triton X-100 as a 

model organic interfering compound. Chemical and instrumental parameters were 

explored for obtaining the optimal metal ions response in the µg/L range. We found that 

mercaptoacetic acid effectively protects the electrode against fouling by relatively high 

Triton X-100 concentration, in the range 100 to 200 mg/L without significantly affecting 

the Pb(II) response, which is almost completely suppressed when the bare bismuth 

electrode is exposed to the surfactant. These preliminary results are promising for the 

possible application of voltammetric sensors based on bismuth working electrode 

surfaces for the direct determination of heavy metals in untreated real samples. 

Acknowledgments: This work is supported by the Spanish Ministry of Science and Innovation 

(project CTQ2008-06657/BQU). 

References 

[1] Herzog, G; Arrigan, D.W. Anal. Chem., 2003, 75, 319 

[2] Herzog, G; Beni, V.; Dillon, P.H.; Barry, T.; Arrigan, D.W. Anal. Chim. Acta, 2004, 511, 137 

[3] Adamovski, M.; Zajac, A.; Gründler, P.; Flechsig, G.U. Electrochem. Commun., 2006, 8, 932 



Electrochemiluminescence of luminol/H 2 O 2 system catalyzed 

by ferrocenes derivatives in solution on I T O electrode 

Diogo Ramadas 1,2 , Ana S. Viana 2 , A.C. Cascalheira 1 

1 Lumisense,Lda, Edifício ICAT, Campo Grande, 1749-016 Lisboa, Portugal 

2 CQB, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 


drsousa@fc.ul.pt 

Luminol is one of the earliest known synthetic compounds exhibiting 

chemiluminescence and has been extensively studied regarding its analytical 

applications. The employment of electrochemiluminescence (ECL) of luminol systems 

onto analytical determinations suffers from a continuous decrease of the light signal 

during consecutive electrode perturbation, which results on poor reproducibility [1]. The 

decrease in the signal has been attributed to the electrode fouling/passivation due to 

deposition of poisoning compounds, products of the ECL reaction. The use of ferrocene 

derivatives as catalysts in the ECL of luminol/H 2 O 2 system was investigated on several 

authors in various electrode materials [2-4]. Most of those studies concern the use of 

ferrocene derivatives as labels for biomolecules and optical ECL detection. However, 

since these derivatives can also function as mediators for the ECL reaction it can be 

envisaged that they can prevent the electrode fouling and consecutively increase the 

stability of ECL systems based on the luminol reaction. 

In this study, we compare the ECL response of an alkaline solution of luminol and H 2 O 2 

in the presence of three different ferrocene derivatives (ferrocene monocarboxylic acid, 

ferrocene dicarboxylic acid, ferrocene carboxaldehyde) onto a ITO electrode, by linear 

voltammetry or potential pulse application. The obtained results indicate that ferrocene 

monocarboxylic acid is the most promising derivative, since it catalyzes the reaction by 

120 mV; the light emission of the system without ferrocene starts at 360mV (vs. SCE) 

whereas in the presence this mediator can be detected at 240mV (vs. SCE). The recorded 

currents corroborate the optical results revealing that the onset of the optical signal 

corresponds to the beginning of the oxidation of the ferrocene derivatives. A systematic 

studied has been also performed in order to study the influence of the: ratio 

concentration of Ferrocene/Luminol, pH, and buffer nature on the reproducibility and 

intensity of the optical signal. 

Acknowledgments: Diogo Ramadas acknowledge Fundação para Ciência e Tecnologia, for 

financial support, project SFRH / BDE / 33797 / 2009 

References 

[1] C. A. Marquettc and L.J. Blum. Anal. Chim. Acta , 1999, 381, p. 1 

[2] R. Wilson and D. Schiffrin. J. Electroanal. Chem., 1998, 448, p. 125 

[3] R. Wilson and D. Schiffrin. Anal. Chem., 1996, 68, p. 1254 

[4] C. E. Taylor, Stephen E. Creager, J.Electroanal.Chem., 2000, 485, p. 114 



Estudio ciclovoltamperométrico de la Nimodipina sobre 

electrodos de carbono vítreo modificados con nanotubos de 

carbono. 

Juan A rturo Squella, Luis J. Núñez-Vergara, Manuel López López 

Laboratorio de Bioelectroquímica. Facultad de Ciencias Químicas y Farmacéuticas. Universidad de 

Chile. Sergio Livingstone 1007. Independencia. Santiago. 

asquella@ciq.uchile.cl 

La nimodipina (Figure 1) es una 4-meta-nitrofenil-1,4-dihidropiridina, que tiene 

actividad farmacológica como bloqueador de los 

canales de calcio al interior de la célula y se usa en la 

terapia cardiovascular. Desde el punto de vista 

electroquímico se han aprovechado sus posibilidades 

tanto para reducirse ( anillo nitrobencenoide) como para 

oxidarse (anillo1,4-dihidropiridínico) en diferentes 

electrodos convencionales. Sin embargo no se ha 

investigado su comportamiento en electrodos modificados con nanotubos de carbono. 

En este trabajo se presenta el comportamiento electroquímico de la nimodipina en 

electrodos de carbono vítreo y en electrodos de carbono vítreo modificados con 

nanotubos de carbono. Se trabajó con nanotubos de multipared oxidados los que fueron 

dispersados en diferentes medios como: H 2 O, 2% Nafion en Etanol y DMF. Se estudió 

el efecto de distintos tiempos de acumulación y concentración de la dispersión sobre la 

respuesta en corriente para la reducción de la nimodipina. 

Se obtuvo una relación directa entre la corriente de pico para la reducción del grupo 

nitro y la concentración de la nimodipina con un límite de detección de 8 x 10 -7 M. 

El comportamiento en el electrodo de carbono vítreo resultó distinto al obtenido sobre el 

mismo electrodo recubierto con los nanotubos de carbono. En el electrodo sin recubrir 

se destaca el pico de reducción debido a la reducción del grupo nitro a hidroxilamina, ya 

sea en el primer barrido o en los siguientes. Por otra parte, en el electrodo recubierto se 

produjo una fuerte adsorción del producto de la reducción del nitro compuesto 

generando un par redox entre los derivados nitroso e hidroxilamina que permanece 

fuertemente adsorbida y es la única que se observa en los barridos sucesivos. Se 

cuantificó la dependencia de las corrientes catódicas y anódicas y su variación con la 

velocidad de barrido encontrándose un comportamiento que da cuenta de un par redox 

nitroso-hidroxilamina inmovilizado en la superficie del electrodo. 

Agradecimientos: 

permitió la estancia de MLL y Proyecto F ONDECYT 1090120. 

Referencias 

[1] J.A.Squella., J. C. Sturm., R. Lenac & Luis J. Núñez-Vergara. Anal. Lett., 1992, 25, 281. 



Iron (II) and Ruthenium (II) Cyclopentadienyl Derivative 

Complexes: new potential antitumor agents 

Milan N. Chhaganlal 1 , M. H. Garcia 1 , M. P. Robalo 2 , V. Moreno 3 

1 CCMM, FCUL, Campo Grande, 1749-016 Lisboa, Portugal 

2 

ADEQ/ISEL, R. Cons.elheiro Emídio Navarro, 1, 1959-007 Lisboa 

3 DQI, Univ Barcelona, Martí y Franquès 1-11, 08028, Barcelona, Spain 

milan001@gmail.com 

The inspiring results already obtained in the search for new ruthenium (II) complexes 

based anticancer drugs [1], stimulated the research for complexes of different metals that 

could give similar properties. We recently report significant effect of toxicity in tumor 

-heteroaromatic sigma 

coordinated ligands [2,3]. This presentation reports our studies in six new 

organometallic derivatives belonging to the family of ruthenium and iron piano stool 

5 -C 5 H 5 )(PP)L] + , with PP= dppe or 2PPh 3 , 

M = Ru (II) or Fe (II) and L = 9-cyanoanthracene or 2-cyanonaphthalene. The 

compounds have been characterized by NMR ( 1 H, 13 C, 31 P), UV-Vis, elemental analyses 

(% C, H, N) and cyclic voltammetry. The electrochemical responses of the metals 

centres are here presented. 

[FeCpDppe(2-‐NC-‐Naphthalene)][PF 6 ] 

1,5 

1 

0,5 

0 

-‐0,5 

-‐1 

E (V) vs SCE 

Figure 1- Cyclic voltammogram of compound [FeCp(dppe)(2-NC-Naph)][PF 6 ] 

in aceto-nitrile at sweep rate of 200 mV/s. 

Acknowledgments: Milan N. Chhaganlal thanks M. H. Garcia for the help and during the 

synthesis and characterization and also M. P. Robalo for the support with the cyclic voltammetry. 

References 

[1] Dyson, P.J. Allardyce, C. S.; Dorcier, A.; Scolaro, C.; Appl. Organomet Chem., 2005, 19, 1. 

[2] Garcia M.H., Morais T.S., Florindo P., Piedade M.F.M., Moreno V., Ciudad C., Noe V., 

J.Inorg.Chem. 2009, 103, 354. 

[3] Moreno V., Lorenzo J., Aviles F.X., Garcia M.H., Ribeiro J.P., Morais T.S., Florindo P., Robalo 

M.P., Bioinorg. Chem Appl. 2010, in press 



Cytotoxicity Studies and DN A Interaction of New Ruthenium 

(II) Cyclopentadienyl Complexes with Nitrogen Coordinated 

Ligands 

Tânia S. Morais 1 , M.H. Garcia 1 , M.P. Robalo 2 , A.Valente 1 , V. Moreno 3 , M. 

Font-Bardia 4 , T. Calvet 4 , J. Lorenzo 5 , F. X. Avilés 5 

1 

CCMM, FCUL, Campo Grande, 1749-016 Lisboa, Portugal; 

2 

ADEQ/ISEL, R. Cons. Emídio Navarro, 1, 1959-007 Lisboa; 

3 DQI, Univ Barcelona, Martí y Franquès 1-11, 08028, Barcelona, Spain; 

4 CMDM, Univ. Barcelona, Martí y Franquès s/n, 08028, Barcelona, Spain; 5 IBB, Univ. Aut. 

Barcelona, 08193, Bellaterra, Barcelona, Spain 

tsmorais@fc.ul.pt 

Ruthenium complexes have been the most widely studied non-Platinum anti-cancer 

candidates. The search in this field both in coordination and organometallic chemistry 

has been certainly stimulated by the successful results already obtained with some 

ruthenium coordination compounds [1,2]. 

We recently report significant effect of toxicity in LoVo and MiaPaca cells of new 

-heteroaromatic sigma coordinated ligands 

[3]. This presentation reports our studies in some new organometallic derivatives 

belonging to the family of piano stool ruthenium cationic compounds, of general 

formula [Ru( 5 -C 5 H 5 )(PP)L] + , with PP=phosphanes and L=N-heteroaromatic ligand. An 

attempt of correlation of the redox potentials of Ru (II) /Ru (III) with cytoxicity of these 

compounds will be done. Also some results will be presented showing our preliminary 

studies by cyclic voltammetric of solutions of the new compounds incubated with DNA. 

The stability of Ru II /Ru III showed by the electrochemical studies suggests the possible 

existence of Ru(III) analogues of this compounds which potential interest might be their 

use as bioreductive prodrugs. 

Figure 1. Cyclic voltammogram of 

compound [RuCp(PPh 3 -bipy)] 

[CF 3 SO 3 ] in dichloromethane at 

sweep rate of 200 mV/s. 

Acknowledgments: The authors thank to F CT (Project PTDC/QUI/66148/2006) for finantial 

support; Tânia S. Morais thanks F CT for his Ph.D Grant (SFRH/BD/45871/2008). 

References 

[1] Dyson, P.J.; Sava, G.; Dalton Trans., 2006, 1929. 

[2] Galanski, M.; Arion, V.B; Jakupec, M.A.; Keppler, B.K.; Curr. Pharm. Des., 2003, 9, 2078. 

[3] Garcia, M.H.; Morais, T.S.; Florindo, P.; Piedade, M.F.M.; Moreno, V.; Ciudad, C; Noe, V.; J. 

Inorg. Biochem., 2009, 103, 354. 



Acid dissociation constants for several potential 

anti-tubercular drugs: 

isoniazid and thiobenzanilide derivatives 

M. C ristina Ventura, 1,2 A. Catarina Bastos, 1 M. João Sarmento, 1 João Manso, 1 

Susana Borges, 1 Vanessa Miranda, 1 Susana Santos, 1 Filomena Martins 1 

1 

Faculdade de Ciências de Lisboa, Departamento de Química e Bioquímica, Centro de Química e 

Bioquímica (CQB), Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal 

2 Instituto Superior de Educação e Ciências, Alameda das Linhas de Torres, 

179, 1750 Lisboa, Portugal 

mcventura@fc.ul.pt 

According to the most recent WHO data [1], tuberculosis (TB) kills 1.8 million people 

every year and one-third of the world's population is currently infected with the 

Mycobacterium tuberculosis (M.tb) bacillus. Moreover, 9.4 million new TB cases were 

reported in 2008 from which 1.4 million refer to people co-infected with HIV. 

Isoniazid (INH) is one of the most powerful first-line drugs in multi-therapeutic 

regimens but an increasing number of M.tb INH-resistant strains have been reported [2]. 

The identification of INH derivatives, or derivatives of other families, with antitubercular 

activity comparable to that of INH but which retain their activity against a 

panel of INH-resistant strains, would obviously be of invaluable importance [3]. 

In the process of screening and pre-formulation of potential new drugs, it is essential the 

knowledge of several physicochemical properties, namely their acid dissociation 

constants (pKa) which affect the passive transport across biological membranes and 

therefore the activity in the living organism. However, many of these compounds are 

scarcely soluble in water, making it necessary to determine their pKa values either in 

organic solvents or in aqueous mixtures and then extrapolate to water. The rationale of 

the effect of pK 

can provide useful information regarding the feasibility of these compounds as drug-like 

candidates. 

In this work we performed solubility and stability tests by UV-Vis spectrometry, at 25.0 

ºC, for several isoniazid and thiobenzanilide derivatives, some of which designed and 

synthesized on the basis of QSAR studies. For each compound, pKa values were 

determined by potentiometry in 4/5 methanol/water mixtures, also at 25.0 ºC. From 

these values aqueous pKa values were computed by extrapolation using the Yasuda 

Shedlovsky method. Bioavailability was assessed on the basis of estimated ionization 

degrees at physiological pH. 

Acknowledgments: This work was funded under project PTDC/QUI/67933/2006. ACB gratefully 

acknowledges a BII grant from F CT/F CUL and MJS a grant from UL/Fundação Amadeu Dias, 

both in 2008/2009. 

References 

[1] WHO Report 2009; Global Tuberculosis Control, Epidemiology, Strategy, Financing, Geneve, 

2009. 

[2] Suarez, J.; Ranguelova, K.; Schelvis, J.P.M.; Magliozzo, R.S. J. Biol. Chem., 2009, 284, 16146. 

[3] Ventura, C.; Martins, F. J. Med. Chem., 2008, 51, 612. 



Bacterial cellulose: A new material for cell immobilization in 

biosensors 

Manuel J. Matos 1,2 , Nelson A. F. Silva 2 , Amin Karmali 2 , Edison Pecoraro 3 

1 Instituto de Telecomunicações, Pólo de Lisboa, Portugal 

2 CIEQB-ISEL - Instituto Superior de Engenharia de Lisboa, Portugal 

3 Instituto de Telecomunicações, Pólo de Aveiro, Portugal 

mmatos@deq.isel.ipl.pt 

A biosensor is an analytical device capable of quantifying the amount of a given analyte 

by means of a transduction process of a biochemical signal that results from an 

interaction between a biological recognition element and the analyte itself. 

A particular a concerns the 

immobilization of the biological element, which can be made directly on the surface of 

the transducing element or by means of an auxiliary support which, then, is placed in its 

immediate vicinity. Encapsulation matrices, polymeric membranes or sol-gel technology 

are examples of these immobilization methods. However, these matrices or 

immobilization supports are mostly synthetic, which, may result in a biologic 

incompatibility between the recognition element and the immobilization support. This 

aspect may lead to some limitations such as reduction of biological activity, premature 

 

To overcome this limitation, our group was able to successfully immobilize living 

microorganisms (whole bacterial cells) on a new material that consists of a biological 

substance resulting from the metabolism of other microorganisms, processed in order to 

fulfill our main immobilization purposes. This material, referred to as bacterial cellulose 

or biocellulose, allowed us to achieve very promising results in living cells 

immobilization [1, 2]. 

In this presentation we compare some analytical characteristics of an electrochemical 

biosensor with potentiometric transduction, used for acrylamide detection, when using 

biocellulose and other traditional matrices, such as polymeric membranes, for the 

immobilization of whole cells of Pseudomonas aeruginosa [3]. Parameters such as 

linear rangewere 

considered. 

References 

[1] Iguchi, M.; Yamanaka, S.; Budhiono, A.; J. Mat. Sci, 2000, 35, 261. 

[2] Pecoraro, E.; D. M. Manzani; Y. M. Messaddeq; S. J. L. R. Ribeiro; Monomers, Oligomers, 

Polymers and Composites from Renewable Resources, Ed. by Naceur Belgacem and 

Alessandro Gandini, Elsevier Science, 2008. 

[3] Silva, N.; Gil, D.; Karmali, A.; Matos, M.; Biocat Biotransf, 2009, 27, 143. 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society PC 01 

A Conducting Polymer / Self-Assembled Monolayer Modified 

Electrode for the Determination of Ascorbic Acid 

José Carlos A. Mesquita 1 , Sónia Maria A. Fernandes 1,2 , Jorge M. G. Teixeira 2 

1 Centro de Química da Madeira. LQCMM/CQM, Universidade da Madeira, 

Campus da Penteada, 9000-390 Funchal 

2 Departamento de Química da Universidade de Évora, Colégio Luís Verney, 7000 Évora 

jcm@uma.pt 

Self-assembled monolayers (SAMs) have become a convenient way of surface 

modification in order to obtain highly organized structures with well-defined properties, 

in particular through the incorporation of appropriate terminate functional groups [1, 2]. 

The technique of electrostatic self-assembly layer-by-layer proposed by Decher et al in 

the 90s, which allows obtaining multilayer thin films, also enables the self-assembly of 

conducting polymers [1]. However, several authors electropolymerize directly 

conducting polymers on SAMs [3] with particularly the intention of obtaining polymer 

layers with increased adherence. 

In this work, it is compared the voltammetric behaviour of the polyaniline (PANI) 

electrodeposited on 3-mercapto-1-propanesulfonic acid (MPS) self-assembled on a 

carbon electrode (C) with that of the PANI chemically synthesized self-assembled by 

electrostatic interaction equally on MPS. Complementarily, the cyclic voltammetric 

study of the PANI deposited on MPS self-assembled on carbon provided valuable 

information about the modified electrodes thus obtained. 

Additionally, it is verified by cyclic voltammetry that with the C/MPS/PANI modified 

electrode it is possible to well define the oxidation of the acid ascorbic (AA), besides not 

arise any further oxidation of this chemical species. Furthermore, it is observed with 

C/MPS/PANI modified electrodes a good correlation of the acid ascorbic voltammetric 

current with their concentration. What gives a positive perspective for the use of this 

kind of modified electrode in the determination of AA. 

Acknowledgments: Sónia Fernandes acknowledges Secretaria Regional da Educação da Madeira 

for the grant. We gratefully acknowledge the NMR Portuguese Networks (REDE/1517/RMN/2005). 

The support from F CT (Pluriannual base funding) and CS Madeira is also gratefully 

acknowledged. 

References 

[1] Paterno, L.G.; Mattoso, L.H.C.; Oliveira Jr. O.N. Quim. Nova, 2001, 24, 228. 

[2] Love, J.C.; Estroff, L.A.; Kriebel, J.K.; Nuzzo, R.G.; Whitesides G.M. Chem. Rev., 2005, 105, 

1103. 

[3] Mazur, M.; Krysinski, P.; Jackowska K. Thin Solid Films, 1998, 330, 167. 



Carbon paper-supported Pd nano-materials for the oxygen 

reduction reaction 

Rosa Rego, 1 C ristina Oliveira 1 , Ana Maria Rego 2 

1 Departamento de Química, Centro de Química - Vila Real, Universidade de Trás-os-Montes e Alto 

Douro, Apartado 1013, 5001-801 Vila Real, Portugal 

2 Centro de Química-Física Molecular and IN, DEQB, Instituto Superior Técnico, Technical 

University of Lisbon, Av. Rovisco Pais 1049-001 Lisboa, Portugal 

mcris@utad.pt 

Most challenges related with polymer electrolyte membrane fuel cells (PEMFC) 

comprises the development of electrodes materials with high electroactivity, surface 

area, life time and low cost. For these reasons, the processes of synthesis of the 

electrocatalyst and deposition onto a gas diffusion layer have become a matter of basic 

and applied research [1]. 

One promising method to minimize electrocatalyst particles size, increase its 

is the electroless deposition 

process [2-4]. Using this deposition methodology the catalyst can be directly deposited 

on a commercial gas diffusion layer (GDL), such as a carbon paper, producing well 

dispersed clusters of nanoparticles. When these clusters are used as electrodes in a fuel 

cell, not only the surface area becomes large, but also the gas and the electrolyte easily 

permeates across, gaining straight access to the catalyst. This methodology will be 

applied to the preparation of Pd cathode catalysts on carbon paper impregnated with an 

hydrophobic material. Its activity towards oxygen reduction reaction in acid and alkaline 

media, will be evaluated envisaging the application of this material to a PEMFC. The 

new nano-Pd materials will be also characterized by SEM/EDS, TEM, DRX and XPS 

techniques. 

References 

[1] Martín, A. J.; Chaparro, A. M.; Galhardo, B.; Folgado, M. A.; Daza, L. J. of Power Sources, 

2009, 192, 14. 

[2] Fujii, T.; Ito, M. Fuel Cells, 2006, 5, 356. 

[3] Beard, K. D.; Schaal, M. T.; Van Zee, J. W.; Monnier, J. R. Appl. Catal. B: Environmental, 

2007, 72, 262. 

[4] Beard, K. D.; Van Zee, J.W.; Monnier, J. R. Appl. Catal. B: Environmental, 2009, 88, 185. 



Formation of mixed self-assembled monolayers of mono- and 

dithiols on Au(111) 

Rafael C. González-Cano, Rafael Madueño, Manuel Blázquez, Teresa Pineda 

Dpto. Química Física y Termodinámica Aplicada, Universidad de Córdoba, Córdoba, SPAIN 

tpineda@uco.es 

Alkanedithiolate self-assembled monolayers (SAMs) can form on Au(111) singlecrystal 

electrodes by the spontaneous formation of a strong gold-sulfur bond with one of 

the SH terminal groups and the attractive van der Waals forces between adjacent alkyl 

chains. The control of the organization of these architectures is of great technological 

importance, and the formation of well-organized layers is needed. In these layers, the 

second unreacted thiol moieties should 

be exposed to the outer surface [1,2]. 

To obtain compact dithiol layers of 

standing-up molecules, the use of a 

mixture of monothiol and dithiol 

derivatives at the appropriate relative 

concentrations that results in an 

almost pure dithiol film, have been 

reported [3]. In this work, we report 

on the formation of a mixed layer of 

octanedithiol (ODT) and octanethiol 

(OT). The formation process is carried 

out under electrochemical control. 

Thus, an exploration of the different 

experimental conditions of ODT/OT 

molar ratio, electrochemical 

deposition potential and deposition 

time is described. 

Figure 1. Cyclic voltammograms for the oxidative deposition of ODT and OT layer in 

0.1 M NaOH solution on Au(111) single crystal electrode. 

In Figure 1, the oxidative deposition of ODT and OT in alkaline solutions are shown. It 

can be deduced that the different peak potentials will drive the formation of a mixed 

layer depending on the ratio of molecules employed. 

Acknowledgments: Project CTQ2007/62723, Junta de Andalucía and Universidad de Córdoba. 

References 

[1] García Raya, D.; Madueño, R.; Sevilla, J.M.; Blázquez, M.; Pineda, T.; Electrochim. Acta, 

2008, 53, 8026. 

[2] García Raya, D.; Madueño, R.; Blázquez, M.; Pineda, T.; J. Phys. Chem. C, 2010, 114, 3568. 

[3] Jiang, W. R.; Zhitenev, N.; Bao, Z. N.; Meng, H.; Abusch-Magder, D.; Tennant, D.; Garfunkel, 

E. Langmuir 2005, 21, 8751. 



Electrochemical control on the formation of mixed 11- 

mercaptoundecanoic acid and octanethiol self-assembled 

monolayers on Au(111) 

Zoilo González-Granados, Rafael Madueño, Manuel Blázquez, Teresa Pineda 

Dpto. Química Física y Termodinámica Aplicada, Universidad de Córdoba, Córdoba, SPAIN 

tpineda@uco.es 

Self assembled monolayers (SAMs) of terminal-functionalized alkanethiols are less 

organized structures than their alkanethiol partner monolayers. The bigger size of the 

terminal group and/or the repulsive interactions between equally charged groups are 

mostly responsible for this disorder. One strategy that can be followed in order to have a 

better organized monolayer is the dilution of the functional groups by using a mixed 

monolayer with a determined ratio of the alkanethiol. In this sense, the mixed 

monolayers can show either a homogeneous 

distribution of the molecules with different 

chemical nature or a phase separated behaviour. 

Any of these properties are useful depending on the 

applications. 

In this work, we present a study of the mixed 

monolayer formed from 11-mercaptoundecanoic 

acid (MUA) and octanethiol (OT) at different 

MUA/OT molar ratios. Taking advantage of the 

different electrochemical behaviour of these two 

molecules on an Au(111) single crystal electrode 

(Figure 1), we prepare these monolayers under 

electrochemical control from an alkaline aqueous 

solution [1]. 

Figure 1. Cyclic voltammetry of 1 mM MUA and 1 

mM OT in 0.1 M NaOH aqueous solution on a 

Au(111) single crystal electrode. 

The differences between the oxidation (deposition) 

and reduction (desorption) potentials for these two 

monolayers can serve as a way of quantification of the composition of the mixed MUA- 

OT layer obtained not only by potentiodynamic but also by potentiostatic methods. 

Acknowledgments: Project CTQ2007/62723, Junta de Andalucía and Universidad de Córdoba. 

References 

[1] García Raya, D.; Madueño, R.; Blázquez, M.; Pineda, T.; J. Phys. Chem. C, 2010, 114, 3568. 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society PD 01 

In-situ study of corrosion morphology of a duplex stainless 

steel in a concentrated LiBr solution and in an impure 

phosphoric acid solution by confocal laser scanning 

microscopy (C LSM) 

R. Leiva-García 1 , M.J. Muñoz-Portero 1 , J. García-Antón 1 

1 

Univ. Politécnica de Valencia, Ingeniería Electroquímica y Corrosión (IEC), Dep. Ingeniería 

Química y Nuclear, Camino de Vera s/n, 46022 Valencia, Spain. 

jgarciaa@iqn.upv.es 

Corrosion has been mainly studied using large-scale experiments. However, corrosion 

mechanisms occur on a smaller scale. Therefore, it can be useful to develop smaller 

scale methods and experimental methodologies. In this way, it will be possible to study 

reduced surfaces. The aim of this work is the study of the corrosion morphology of a 

duplex stainless steel (UNS 1.4462) in a concentrated aqueous LiBr solution (992 g/L) 

and in an impure phosphoric acid solution, containing chlorides and sulfates. 

The electrochemical techniques used were cyclic potentiodynamic curves and 

galvanodynamic curves. Tests were carried out in a minicell developed by this research 

group. This cell can be put in the stage of a confocal laser scanning microscope. In this 

way, the in-situ observation of the corrosion process at microscopic scale is possible. All 

the tests were made at 25 ºC. 

The LiBr solution is an aggressive solution that provokes localized corrosion in the 

duplex stainless steel. During the potentiodynamic curves, pits appear in the electrode 

surface when the pitting potential is reached. These pits grow until affect the entire 

electrode surface. When this growth is observed at higher magnifications (200x and 

500x), the formation of new small pits is observed in the unaffected area (covered with 

the corrosion product) closed to the corrosion front. Then, this corrosion front reaches 

the pits and the observed surface ends completely damaged. In the case of the 

galvanodynamic curves, a pit appears in the electrode surface when the pitting potential 

point is reached and it goes growing in a sequential way with the increase of the current 

density. 

With regard to the impure phosphoric acid solution, the potentiodynamic and 

galvanodynamic tests indicate that corrosion of duplex stainless steel is generalized in 

this medium. The images obtained at different magnifications (100x - 500x) show how 

the grain boundary of the tested stainless steel goes being revealed with the increase of 

the current density. Despite of the presence of impurities, their concentration is not 

critical to produce a localized corrosion attack. 

Therefore, the developed minicell is useful to study the morphological differences 

among different kinds of corrosion attack at microscopic scale. 

Acknowledgments: We wish to express our gratitude to MICINN (CTQ2009-07518), to F EDER, to 

MAEC (PCI Mediterraneo C/8196/07, C/018046/08, D/023608/09) for their financial support and 

to Dr. Asunción Jaime for her translation assistance. 



Copper corrosion in soils contaminated with chloride ions 

Carla Barradas Dias 1 , M. M. M. Neto 1,2 , I. T. E. Fonseca 1 

1 CCMM, Departamento de Química e Bioquímica da Universidade de Lisboa, Campo Grande 

Ed C8,1749-016 Lisboa, Portugal 

2 UIQA, Instituto Superior de Agronomia, TU Lisbon, Tapada da Ajuda, 1349-017 Lisboa, Portugal 

carlabarradasdias@gmail 

Soils are, in general, very complex matrices; physical conditions (pH, porosity, humidity 

degree, oxygenation and conductivity, among others) and the presence of different ions 

in soils may induce corrosion on buried metallic structures and pieces leading to its 

deterioration. Toxic species released during the corrosion processes can affect soils 

causing serious contamination problems. On the other hand, the deterioration of metals 

such as copper and copper alloys used in buried electricity earthing systems may give 

rise to safety problems. 

Thus, studies on the behaviour of metallic samples, buried in soils with different degrees 

of agressivity, are an important topic in materials as well as in environmental sciences. 

Following previous studies 1, we have carried on working in this type of subject. 

The present communication reports a study performed with a set of copper samples 

buried, during a 3 month period, in soil samples with different degrees of aggressivity, 

particularly, with different chloride contents (Cl - : 0.01 to 0.5 M). The initial soil 

sample was characterized and the other modified soil samples were prepared by the 

addition of different amounts of chloride ions. 

Copper coupons were characterized before the test and after being removed from the soil 

samples in which they have been buried. The analysis was performed by visual 

observation and different techniques, namely optical microscopy, gravimetry, scanning 

electron microscopy (SEM) and X-Rays diffraction spectroscopy (DRX). 

Another set of experiments was performed with a copper electrode immersed in 

solutions made with different chloride concentrations, using the soil washing water as 

solvent (Cl - : 0.01 to 0.5 M), at constant pH of 6.4 (pH value of the original soil 

sample). The effect of acidifying the medium was also studied; studies were performed 

at pH 6.4, 5.8 and 4.8. 

Acknowledgments: CCMM (Centro de Ciências Moleculares e Materiais) and UIQA (Unidade de 

Investigação de Química Ambiental) are grant aided by F CT (Fundação para a Ciência e 

Tecnologia). 

References 

[1] Afonso, F. S.; Neto, M. M. M.; Mendonça, M. H.; Pimenta, G.; Proença, L.; Fonseca, I. T. E., J 

Solid State Electrochem., 2009, 13, 1757. 



Estudo da eficiência de duas técnicas na remoção de cloretos 

em amostras de uma bala de canhão de um naufrágio do 

séc. X V III 

João Carlos Coelho 1,2 , M. D. Carvalho 1 , I. T. E. Fonseca 1 

1 CCMM, Departamento de Química e Bioquímica da Universidade de Lisboa, Campo Grande 

Ed C8,1749-016 Lisboa, Portugal 

2 Divisão de Arqueologia Náutica e Subaquática, Instituto de Gestão do Património Arquitectónico e 

Arqueológico IP, Av. da Índia, 136, 1300-300 Lisboa, Portugal 

e-mail: jcoelho@igespar.pt 

No estudo da corrosão de artefactos arqueológicos em metal, tendo como objectivo o 

desenvolvimento de tratamentos e metodologias para a sua conservação, têm sido 

utilizados métodos electroquímicos, em conjugação com outras técnicas de análise. No 

caso específico de artefactos em ferro provenientes de contextos arqueológicos 

aquáticos, nomeadamente marinhos, a remoção dos iões cloreto constitui a principal 

intervenção, tendo como objectivo final impedir o prosseguimento do processo de 

corrosão e remover os produtos de corrosão formados durante ao período de exposição 

do0 artefacto. 

Nesta comunicação serão apresentados resultados de um estudo que visa proceder à 

aplicação de tratamentos de conservação de artefactos em ferro arqueológico, usando 

diferentes técnicas, tais como: redução electrolítica, redução galvânica, redução com 

sulfito alcalino, imersão em água desionizada e imersão em soluções alcalinas, de modo 

a avaliar a sua eficácia, tanto ao nível de estabilização/remoção de cloretos, como 

também de redução de produtos de corrosão nas camadas superficiais. 

O material utilizado são amostras retiradas de uma bala de canhão em ferro fundido de 

meados do século XVIII, inserida no contexto arqueológico de um navio almirante 

francês, de nome Océan, que naufragou junto à costa sul de Portugal, em 1759. 

Os ensaios foram efectuados tanto em amostras mantidas húmidas, desde o momento da 

sua recolha, como em amostras secas propositadamente, em condições controladas. 

O conjunto de amostras, antes e após a aplicação dos métodos de tratamento (remoção 

de cloretos), é analisado por voltametria cíclica, difracção de raios-X (XRD), 

microscopia electrónica de varrimento e microanálise de raios-X (SEM/EDS). 

Serão apresentados resultados obtidos através da aplicação do método de redução 

electrolítica e de simples imersão em soluções alcalina, com monitorização do potencial 

em circuito aberto (OCP). A eficiência dos dois métodos na extracção de cloretos é 

calculada com base na análise de cloretos nas respectivas soluções de imersão 

prolongada das amostras, utilizando um eléctrodo selectivo de iões cloreto. 

Agradecimentos: CCMM (Centro de Ciências Moleculares e Materiais) é suportado 

financeiramente pela F CT (Fundação para a Ciência e Tecnologia). 



Electrochemical characterization of polypyrrole-based 

conducting fabrics in different pH media 

Javier Molina, Javier Fernández, Ana Isabel del Río, José Bonastre, 

Francisco Cases 

Departamento de Ingeniería Textil y Papelera, EPS de Alcoy, Universidad Politécnica de Valencia, 

Plaza Ferrándiz y Carbonell s/n, 03801 Alcoy, Spain 

jamopue@doctor.upv.es 

Conducting fabrics of polyester covered with polypyrrole have been electrochemically 

characterized at different pHs (1, 7 and 13). The stability of the conducting fabrics in 

different pHs is fundamental in views of its application in electronic textiles or 

electrocatalysis. In the study, two counter ions have been employed: AQSA (organic) 

and PW 12 O 3- 40 (inorganic). The electrochemical techniques that have been employed for 

the electrochemical characterization have been cyclic voltammetry (CV) and scanning 

electrochemical microscopy (SECM). It has been demonstrated the influence of the scan 

rate in the form of the voltammograms obtained. High scan rates (50 mV·s -1 ) did not 

allow the observation of the redox processes and a resistive response was obtained. On 

the other hand, low scan rates (1mV·s -1 ) allowed the apparition of the redox peaks. The 

charge transfer is produced across the polymer chains since polyester is an insulating 

material. Lower pHs produced a higher and more characteristic electrochemical 

response due to the influence of protonation on the polypyrrole activity [1]. 

SECM allows the possibility of studying zonal electroactivity at its open circuit 

potential. Approach curves were obtained by SECM for the samples of PPy/AQSA and 

3- 

PPy/PW 12 O 40 treated at different pHs. Positive feedback was obtained for all the 

conducting fabrics samples, so the fabrics were electroactive. The degree of positive 

feedback varied on the nature and the treatment of the polypyrrole layer. An increase in 

the pH of the solution caused the loss of part of the counter ions as XPS measurements 

have revealed and the layer electroactivity was affected. The organic counter ion was 

more stable than the inorganic one at pH 13. This is due to a reaction of decomposition 

that suffers the PW 12 O 3- 40 at pH>8.3 [2]. The PW 12 O 3- 40 decomposed into PO 3- 4 and 

WO 2- 4 [2]. 

Acknowledgments: Authors thank to the Spanish Ministerio de Ciencia y Tecnología and European 

Union Funds (F EDER) (contract CTM2007-66570-C02-02) and Universidad Politécnica de 

Valencia (Programa de apoyo a la investigación y desarrollo de la UPV (PAID-05-08)) for the 

financial support. J. Molina and A.I. del Río are grateful 

(Generalitat Valenciana) and the Spanish Ministerio de Ciencia y Tecnología respectively for the 

FPI fellowship. 

References 

[1] Krzysztof M. Electroanalysis, 2006, 18, 1537. 

[2] Zu Z.; Tain R.; Rhodes C. Canadian Journal of Chemistry, 2003, 81, 1044. 



Influence of Molybdenum on electronic structure of passive 

films on stainless steels 

M.A. Catarino, 1 M.I. Godinho, 1 L. Freire, 2 M. da Cunha Belo, 2 

A.M.P. Simões, 2 M.J. Ferreira, 1 M.F. Montemor 2 

1 ISEL, Área Departamental de Engenharia Química, Av. Conselheiro Emídio Navarro, 1, 


2 ICEMS Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 


acatarino@deq.isel.ipl.pt 

The study concerns the passive state of AISI type 304 and 316 stainless steels created in 

aqueous solutions of different pH, in the alkaline range (13-9), at room temperature 

without and with chloride additions. Experimental work is carried out by capacitance 

measurements using the Mott-Schottky method. 

The objective is to establish the influence of molybdenum which is a very important 

alloying element in the case of the 316 stainless steel. 

It has been demonstrated that molybdenum decreases the doping density of the 

constitutive oxides of the passive films formed in the neutral borate/boric solutions 

( pH 9) [1]. 

Now, the results obtained with the solutions under study show that the capacitance 

behaviour of both stainless steels can be related to the existence of a diphasic passive 

films formed by an inner chromium rich oxide layer of p-type semi-conductivity and an 

outer iron rich oxide layer of n-type. From the analysis of the slopes of the Mott- 

Schottky plots, it can be concluded that the doping densities are not so high for films 

formed on 316 stainless steel, this means that molybdenum increases the thickness of the 

space charge layer at film-solution interface and probably also modifies the depletion or 

accumulation of charges at metal-film interface. 

Further, molybdenum can affect the electrical potential barrier situated inside the 

passive film where the transition from p-type to n-type conduction occurs, like the other 

two interfaces. This special junction (n-p) is a source of structural defects and influence 

migration processes. 

The electronic band structure model proposed to explain electron distribution considers 

that the passive film is very highly doped but can be described by the Boltzmann 

statistics. The Fermi level is placed in the Urbach tail where localized energy states 

could intervene in the electronic transfer of charges. 

Acknowledgments: Project PTDC/ECM/69132/2006. 

References 

[1] Hakiki, N.E.; Da Cunha Belo, M.; Simões, A.M.P.; Ferreira, M.G.S. J. Electrochem. Soc., 1998, 

145, 3821. 



Corrosion behaviour of quaternary bronzes in slightly 

passivating environments 

Mariano Pérez, Maurizia Calvisi, Gemma Mª. González-Mesa 

Departamento de Química Física. Universidad de La Laguna. Tenerife. España 

mjperez@ull.es 

This communication show the first results of a work on corrosion/protection 

of bronze materials. This work has been developed from the factory ingots (first 

foundry) of quaternary bronze materials and from the so called chimney residuals 

resulting from a second cast bronze materials used for filling the sculpture molds. 

The deviation of compositions and crystalline structure of both first and second foundry 

bronzes have been studied by SEM/EDS and DRX and compared to the ingots factory 

specifications. 

Metal samples shaped as planar disks, as received from the factory (EB), were 

kept in natural atmosphere, not specially corrosive (indoors), for 10-12 months. Then 

they were characterized by SEM-EDX, noticing the topographic and composition 

variations due to this oxidation period respect to their initial status. 

Following the results of the previous observations the redox characterization 

of these materials were carried out with the abovementioned shaped disk samples as 

working electrodes, by cyclic voltammetry in a slightly passivating environment, 

aqueous sodium tetraborate solution (pH 9.3), to detect components peaks in the records 

made and trying to assign them to redox couples of the metal components of these 

alloys. 

In parallel, the same type of voltammetric records were carried out with metal 

samples of the main alloy components, that is, the components of the studied quaternary 

bronze alloys, namely, copper, tin, zinc and lead. 

Correlation of redox characteristics and corrosion behaviour versus the 

crystalline structure of these quaternary alloys are attempted [1]. 

Acknowledgments: enterprise and materials 

supplier.2.SEM/EDS and XRD SEGAI Services from ULL. 3 Prof. L. Galindo. Depto. Quimica 

Analítica. ULL. 

References 

[1] 



Complementary application of localized and electrochemical 

techniques to reveal self-healing ability in small defects 

M. Taryba 1 , D. Snihirova 1 , S. Lamaka 1 , M.F. Montemor 1 , M.G.S.Ferreira 1,2 

1 

ICEMS, Instituto Superior Técnico, Technical University of Lisbon, Portugal 

2 CICECO, Dep.Ceramics and Glass Eng., University of Aveiro, Aveiro, Portugal 

maryna.taryba@ist.utl.pt 

Data for characterization of self-healing ability of anticorrosion coatings applied on 

galvanized steel samples was provided by Scanning Vibrating Electrode Technique 

(SVET), Scanning Ion-selective Electrode Technique (SIET), Scanning Electron 

Microscopy coupled with Energy Dispersive Spectroscopy (SEM/EDS) and 

Electrochemical Impedance Spectroscopy (EIS). The analyzed coatings contained 

nanoreservoirs filled with different corrosion inhibitors. SVET system allowed for 

locating cathodic and anodic activity, SIET technique characterized acid-base equilibria 

of the corrosion process, SEM/EDS measurements supplied information about the 

composition of corrosion products and their distribution, EIS was used to estimate 

general barrier properties of the coatings under consideration. The research aims to show 

the advantages of complementary use of localized and conventional electrochemical 

techniques in terms of their application for better understanding and description of 

corrosion and self-healing mechanisms. 

Acknowledgments: -LA-2008-214261 is gratefully 

acknowledged. 



Gold Electrodeposition from Ionic Liquids: 

an Alternative to Conventional Aqueous Baths 

A.I.de Sá 1 , C.M. Rangel 1,2 , S. Quaresma 2 , S. Eugénio 2 , R. Vilar 2 

1 Laboratório Nacional de Energia e Geologia, Paço do Lumiar 22, 

Unidade de Pilhas de Combustível e Hidrogénio 1649-038 Lisboa, Portugal 

2 

Departamento de Materiais, Instituto Superior Técnico, 

Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal 

carmen.rangel@ineti.pt 

Ionic liquids have been proven to be suitable as electrolytes for the electrodeposition of 

different metals as well as semiconductors materials [1]. In this work, an alternative bath 

for gold electroplating based on 1-butyl-1-methylpyrrolidinium dicyanamide (BMP- 

DCA) is proposed. The selection was based on the physical and chemical properties of 

the ionic liquid, including its viscosity, conductivity and strong complexing capability 

[2]. The bath was prepared by adding HAuCl 4 .3H 2 O to the as received-ionic liquid, 

experiments were performed under laboratory atmospheric conditions. The water uptake 

of the ionic liquid was followed by Karl-Fischer titration and its effect on 

conductivity and on the electrochemical profile was evaluated. Cyclic voltammograms 

were recorded using glassy carbon (see figure 1), nickel and copper as electrodes in 

order to characterize the gold reduction processes on the different substrates. Results 

suggested a two step reduction, under diffusion control. Nanocrystalline gold thin films 

were obtainable under potentiostatic control (-1 V, 1500 s) on copper and nickel 

electrodes at temperatures from 20 to 80ºC. The influence of temperature on the kinetics 

and morphology of gold deposits will be discussed. Characterization of the deposits was 

performed by XRD, SEM and TEM. 

i mA cm -2 

8.0E-04 

E / V 

-1.6 1 

-6.0E-04 

Fig. 1 Typical cyclic voltammogram (100 mVs -1 ) obtained on glassy carbon in 0.020 M 

HAuCl 4 .3H 2 O + BMP-DCA at 298 K. 

Acknowledgements 

This work was financed by Fundação para a Ciência e Tecnologia (F CT), under contract nº 

PTDM/ CTM/68847/2006. S. Quaresma and S. Eugénio also acknowledge F CT for the provision of 

grants. 

References 

[1] Abedin S.Z.E, and Endres F., Chemphyschem, 2006, 7, 58 

[2] Deng M-J, Chen P-Y, Leong T-I, Sun I-W, Chang J-K and Tsai W-T, Electrochem. Commun., 

2008, 10, 213. 



Effect of chloride and sulphate ions on the electrochemical 

behaviour of an austenitic stainless steel, the H A Z and the 

welded metal in phosphoric acid medium at different 

temperatures 

Blasco-Tamarit, E.; García-García, D.M.; Ibáñez-Ferrándiz, M.V.; 

García-Antón, J. 

Ingeniería Electroquímica y Corrosión (IEC). Departamento de Ingeniería Química y Nuclear. 

E.T.S.I.Industriales. Universidad Politécnica de Valencia. P.O. Box 22012, E-46071 Valencia. 

Spain. 

jgarciaa@iqn.upv.es 

Industrial phosphoric acid solutions are chemically complex and their analysis changes 

from one plant to another, depending on the quality of phosphate ores and the process 

utilized. Phosphoric acid produced according to the wet process, in which the phosphate 

ores are attacked by sulphuric acid, is the most important of such chemicals. During the 

wet process, impurities as chlorides and sulphides are incorporated to the phosphoric 

acid, which becomes this acid in the most aggressive industrial phosphoric acid. So that, 

severe corrosion problems on the equipments used in this industry take place. In this 

sense, the austenitic stainless steels are a good choice to be used in phosphoric media 

due to their high corrosion resistance. 

The objective of the this work was to study the effect of the impurities (chlorides and 

sulphates) on the electrochemical behaviour of a highly alloyed austenitic stainless steel 

(UNS N08031) used as base metal, the welded metal obtained by TIG (Tungsten Inert 

Gas) welding using a Nickel-base alloy (UNS N06059) as filler metal, and the Heat 

Affected Zone (HAZ) of the base metal. The materials have been tested in two solutions: 

pure 5.5 M phosphoric acid solution and 5.5 M phosphoric acid solution polluted with 

379.2 ppm of chloride ions and 2wt% of H 2 SO 4 . Tests were developed at 25 ºC, 40ºC, 

60ºC and 80ºC. 

Open Circuit Potential tests and potentiodynamic anodic polarization curves were 

carried out to obtain information about the electrochemical behaviour of the materials. 

Corrosion potentials and corrosion current densities were obtained from Tafel analysis. 

The critic potentials and the passivation current densities of the studied materials were 

also analysed. 

The most important influence of impurities was observed on the critic potential obtained 

from the potentiodynamic curves. More active values of critic potential were obtained in 

the polluted solution than in the pure solution. This fact means that the presence of 

impurities makes the rupture of the passive film easier. 

Acknowledgments: We wish to express our gratitude to Programa de Apoyo a la Investigación y 

Desarrollo de la Universidad Politécnica de Valencia (PAID-06-09 and to the Ministerio de 

Asuntos Exteriores y Cooperación of Spain (PCI Mediterráneo C/8196/07, Ref. C/018046/08, and 

D/023608/09). 


XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society PE 01 

Some aspects of the electrochemical reduction of the herbicide 

imazamethabenz acid on mercury electrodes 

Sara Pintado Benzal, 1 Mercedes Ruiz Montoya and José Miguel Rodríguez 

Mellado 

1 

Departamento de Química Física y Termodinámica Aplicada. Universidad de Córdoba. Campus de 

Rabanales edificio Marie Curie 2ª planta (España) 

q02pibes@uco.es 

The knowledge of the electrochemical behaviour of pollutants can contribute to the 

development of methods able to eliminate such compounds or, at least, to decrease their 

toxicity. Other imidazolinone herbicides such as imazapyr, imazethapyr or imazaquin 

have been studied by the authors [1]. Imazamethabenz acid differs from these 

compounds in the aromatic part (a benzoic acid rest) that is non-reducible in aqueous 

media (scheme 1). So, the reducible part of the molecule must be the imidazolinone ring 

as found for imazamethabenz methyl [2] 

(a) (b) (c) 

Scheme 1: Structures of (a) imazapyr, (b) imazaquin, and (c) imazamethabenz acid 

Polarographic and voltammetric studies have been made on mercury electrodes from 

strongly acidic media (0.12.7 M H 2 SO 4 ) to pH 12. The overall reduction process 

involves the uptake of two electrons, the following species being reduced [2, 3]: 

C H 3 

H 

O N 

N + 

CH CH3 

H 

CH 3 

O 

R 1 

R 2 

C 

OH 

-2H + 

2H + 

C H 3 

H 

O N 

N 

CH CH3 

CH 3 

O 

R 1 

R 2 

C 

O 

- 

- H + 

H + 

R 1 

O N - R 2 

H 3 C N 

CH CH3 C - 

CH 3 

O O 

In strongly acidic media (pH


Electrochemical and Spectroelectrochemical Study of 

Alkyl-Substituted Heptathienoacenes 

C. Capel Ferrón a,b , B. Vercelli b , G. Zotti b , 

Mingqian He c , Weijun Niu c , V. Hernández a , J. T. López Navarrete a 

a 

Department of Physical Chemistry, Málaga University, 29071 Málaga (Spain) 

b 

Institute for Energetics and Interphases-IENI CNR, C.so Stati Uniti, 4, 35127 Padova (Italy) 

c Corning Incorporated, SP-FR-6, Corning, New York 14830 

capel@uma.es 

Conjugated organic molecules such as pentacene have been widely used as organic 

field-effect transistor (OFET) materials. Oligothiophenes with complete ring fusion, are 

of particular interest due in part to their fully planar structure which avoids 

conformational disorder and more efficient molecular packing than usual 

oligothiophenes, they adopt face-to- face packing motifs in contrast to face-to-edge or 

herringbone packing commonly found in -linked oligothiophenes. 

Here we consider a series a serie of capped heptathienoacenes. [1] 

S 

S 

S 

S S 

2D-7T 

S 

S 

H 3 C S S S CH 3 

C 10 H 21 S S S S C 10 H 21 

2D M-7T 

C 10 H 21 C10 H 21 

S 

C 10 H 21 S S S C 10 H 21 

C 10 H 21 S S S S C 10 H 21 

4D-7T 

Si 

S S S 

S S 

T IPS-7T-T IPS 

S 

Si 

The occurrence of -dimerization in these flat thienoacenes upon oxidation has been 

checked with the 7T compounds bearing scarcely hindering C 10 H 21 - or CH 3 -moieties. 

The spectroelectrochemistry of 2D-7T, 2MD-7T and 4D-7T displays a broad band at ca. 

700 nm assigned to the formation of -dimers, however the UV-Vis-NIR spectrum of 

TIPS-7T-TIPS upon oxidation at 700 mV exhibits two bands around 575 nm and 1028 

nm, typical of insolated radical cations. The formation of -dimers in this oligomer is 

hindered by the bulky TIPS groups incorporated in its terminal alpha positions. [2] 

References 

[1] Mingqian He and Feixia Zhang , JOC, 2007, 72, 442-451. 

[2] J. Aragó; M. Viruela; E. Ortí; R. Malavé Osuna; B.Vercelli; G. Zotti; V. Hernández; J. T. 

López Navarrete; J. T. Henssler; A. J. Matzger; Y. Suzuki; and Shigehiro Yamaguchi, Chem. 

Eur. J., 2010, DOI: 10.1002/chem.200903343 



Evaluation of the antioxidant capacity of imidazoimidazole 

phenolic derivatives by cyclic voltammetry 

F. Gomes, A.P. Bettencourt, C. Correia, M.A. Carvalho, M.F. Proença 

Departamento de Química, Universidade do Minho, 4710-057, Braga, Portugal 

figs8@hotmail.com 

The human organisms are exposed to reactive species (ROS) and the action of free 

radicals can potentiate redox reactions that can cause several diseases [1,2]. The use of 

compounds with antioxidant activity is expected to be useful for the prevention and 

treatment of these diseases [1,2]. Therefore, there has been a growing interest in finding 

novel antioxidants in order to meet the requirements of pharmaceutical industries. 

It is also essential to have a simple and fast method to measure the antioxidant capacity 

of new compounds. So, several methods have been developed and used to evaluate the 

capacity of a compound to act as an antioxidant, including chemical and electrochemical 

methods [3]. 

Electrochemical approaches for evaluating antioxidant capacity used have been 

controlled-potential techniques [4, 5]. 

In this work several novel phenolic compounds based on an imidazoimidazole structure 

with potential antioxidant capacity were synthesized and their antioxidant activity 

evaluated by cyclic voltammetry. Cyclic voltammetry has been used to measure the ease 

of oxidation of the synthesized phenolic compounds and the anodic peak potential is 

employed as a predictor of antioxidant capacity. 

The effect of the nature of the substituent R and the position of hydroxyl groups in the 

substituent R 2 on the oxidation potentials of the compounds is evaluated. The 

antioxidant activities estimated by means of the anodic peak potentials were compared 

with data obtained for Trolox, a commercial derivative of vitamin E with high 

antioxidant activity routinely used as reference compound. 

R 

N 

NH 

R 1 

N 

N 

CONH 2 

Figure 1 - Imidazoimidazole structure 

Acknowledgments: F. Gomes acknowledges to F CT for the Integration into Research Grant, 

Centro de Química, Universidade do Minho. 

References 

[1] Valko, M.; Rhodes, C. J.; Moncola, J.; Izakovic, M.; Mazur, M. Chemico-Biological Interac. 

2006, 160, 1. 

[2] Halliwell, B. Biochem. Pharmacol. 1995, 49, 1341. 

[3] Huang, D. ; Ou, B.; Prior, R.L., J. Agric. Food Chem. 2005, 53,1841. 

[4] Blasco, A.J.; Crevillén, A.G.; González, M.C.; Escarpa, A. Electroanalyis 2007, 19, 2275. 

[5] Bortolomeazz, R.; Sebastianutto, N.; Toniolo, R.; Pizzariello, A. Food Chem. 2007, 100, 1481. 



Complexes for N L O : Cyclic Voltammetry Study 

Ana M. Santos 1,2 , Paulo J. Mendes 2 , Tiago J. L. Silva 1 , M. H. Garcia 1 , M. P. 

Robalo 3 

1 FCUL, Campo Grande, 1049-001 Lisboa, Portugal 

2 Centro de Química de Évora, R. Romão Ramalho 59, 7000-671 Évora, Portugal 

3 

ADEQ/ISEL, R. Conselheiro Emídio Navarro, 1, 1959-007 Lisboa 

margaridaggs@gmail.com 

Organometallic compounds continue to attract considerable interest owing to their 

application in the field of nonlinear optics (NLO) [1]. For second-order nonlinear optics, 

strongly asymmetric systems are needed, which led to the development of typical push 

pull systems in which the metal centre, bound to a highly polarizable conjugated 

backbone, acts as an electron donor (D) or acceptor (A) group. This is the case of the 

5 -monocyclopentadienylmetal complexes presenting benzene- or 

thiophene-based conjugated ligands coordinated to the metal centre through nitrile or 

acetylide linkages which revealed to be much more efficient donor groups for secondorder 

NLO purposes than the traditional organic donor groups [2,3]. Recently, a new 

promising approach has emerged that is the concept of switchable second-order 

nonlinear optical (SONLO) properties [4]. This makes possible to achieve a switch in 

the SONLO response between two forms since they have great difference in the 

magnitude of the corresponding first hyperpolarizabilities. The hyperpolarizability can 

be altered, for instance, by reducing the donor capacity of the donor moiety (D) by 

oxidation. Thus, the presence of redox-active metal centers together with a 

hyperpolarizable conjugated framework provides good opportunities for modulation of 

molecular NLO responses, and is hence a primary justification for the study of these 

systems. 

The cyclic voltammetry (CV) plays a role in this field. Besides the information about the 

electron richness of redox-active centres and the correlation with spectroscopic 

properties, CV can give an insight on the reversibility/stability of oxidized and reduced 

species. In our ongoing work on the study of organometallic compounds with molecular 

5 -monocyclopentadienyliron(II) and 

nickel(II) complexes with substituted thiophene-based ligands in view of the potential 

use of these systems as switchable SONLO molecules. 

Acknowledgments: We thank to COMPETE/F EDER for financial support (F COMP-01-0124- 

F EDER-007433). 

References 

[1] Goovaerts, E; Wenseleers W.; Garcia, M.H.; Cross G.H. Handbook of Advanced Electronic and 

Photonic Materials, Ed. H.S. Nalwa, 2001, 9, 127. 

[2] Powell, C.M.; Humphrey, M. G. Coord. Chem. Rev. 2004, 248, 725. 

[3] Garcia, M.H.; Mendes, P. J.; Robalo, M.P.; Duarte, M.T.; Lopes, N. J. Organomet. Chem. 2009, 

694, 2888. 

[4] Asselberghs, I.; Clays, K.; Persoons, A; Ward M.; McCleverty, J. J. Mater. Chem. 2004, 14, 

2831. 



Electrochemical studies of Cu I -scorpionate complexes 

Riccardo Wanke, 2 Luísa M.D.R.S. Martins, 1,2 Armando J.L. Pombeiro 2 

1 Área Departamental de Engenharia Química, ISEL, R. Conselheiro Emídio Navarro, 1959-007 

Lisboa, Portugal. 2 Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Av. 

Rovisco Pais, 1049-001 Lisboa, Portugal 

lmartins@deq.isel.ipl.pt 

Metal complexes of scorpionate ligands, in particular of tris(pyrazolyl)borates (Tp), 

constitute one of the most extensively studied classes in inorganic, organometallic and 

bioinorganic chemistries. 

The study we now report aimed at the synthesis and investigation of the coordination 

ability of a new C-scorpionate that could combine flexibility and water solubility with 

the sterically demanding features of the 3-substituted tris(pyrazolyl) ligands. For these 

purposes, we designed the new sterically hindered tris(1-pyrazolyl)methane sulfonate 

[SO 3 C(pz Ph ) 3 ] - , (Tpms Ph ) - derivative, bearing a phenyl group at the 3-position of the 

pyrazolyl rings (Fig. 1). When ligating a metal centre, such a bulky species would be 

tion position(s) of the 

complex. 

A series of copper(I) complexes bearing 

(Tpms Ph ) - has been prepared 1 and the 

electrochemical behaviour has been studied 

by cyclic voltammetry and controlled 

potential electrolysis at Pt electrodes, 

namely for complexes such as 

[Cu(Tpms Ph )(MeCN)] (1) and 

[Cu(Tpms Ph )(PTA)] (2) (PTA = 1,3,5- 

triaza-7-phosphaadamantane). 

Complexes 1 and 2 display an irreversible 

process ascribed to the Cu(I) to Cu(II) 

Fig.1 

oxidation. 

The electrochemical behaviour of the above complexes has been interpreted in terms of 

the electronic properties of the ligands and confirms the observed 1 solution 1 H-NMR 

and solid state X-ray diffraction data. For instance, for 2 the higher electron withdrawing 

effect of the ligated phosphine (i.e. PTA) hampers the oxidation of metal center and 

favours the N,N,N-coordination mode of the scorpionate ligand, whereas at 1, Tpms Ph 

adopts the less electron releasing N,N,O-mode. 


Technology (F CT), Portugal, and its PPCDT 

References 

[1] Wanke, R.; Smolénski, P.; Guedes da Silva, M. F. C.; Martins, L. M. D. R. S., Pombeiro, A. J. 

L., Inorg. Chem., 2008, 47, 10158. 



Electrochemical behaviour of C-functionalized or substitutedpyrazolyl 

scorpionate cobalt complexes 

Telma F.S. Silva, 1 Luísa M.D.R.S. Martins, 1,2 Armando J.L. Pombeiro 1 

1 Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais, 1049- 

001 Lisboa, Portugal. 2 Área Departamental de Engenharia Química, ISEL, R. Conselheiro Emídio 

Navarro, 1959-007 Lisboa, Portugal. 

tsilva@dem.isel.ipl.pt 

Scorpionates have become well-established as ligands in coordination and 

organometallic chemistry, and their complexes have made important contributions in 

numerous different areas, such as modeling of metallo-enzymes and catalysis. 1 

In pursuit of our interest on the coordination chemistry of C-scorpionates towards 

several transition metals, 2 we now report the electrochemical study of our recently 

obtained half- or full-sandwich cobalt complexes 1-4 prepared by reaction of cobalt(II) 

chloride with LiSO 3 C(pz) 3 , HC(pz Ph ) 3 or OHCH 2 C(pz) 3 (pz = pyrazolyl): 

[Co{HC(pz) 3 }(OSO 2 OH)(OCH 3 ) 2 ] 1, [CoCl 2 {3Ph-pzH} 3 ] 2 2, [Co{3Ph-pzH} 4 ]Cl 2 3 or 

[Co{OHCH 2 C(pz) 3 } 2 ].[Co{OHCH 2 C(pz) 3 }(H 2 O) 3 ](Cl) 2 .2H 2 O 4. 

All the studies have been carried 

out by cyclic voltammetry (CV) at 

a Pt-disc electrode or controlled 

potential electrolysis (CPE) at a 

Pt-gauze electrode, in a 0.2 M 

Bu 4 NBF 4 /NCMe or DMSO 

solution. 

The electrochemical behaviours 

are discussed in terms of electron 

richness of the Co centres and the 

electronic properties of the 

ligands. 

Fig.1 - Cyclic voltammograms of 4, initiated by the 

anodic sweep, at a Pt disc electrode, in a 0.20 M 

n Bu 4 N[BF 4 /NCMe solution, in the scan rate range 

50 - 400 Vms -1 . 

Acknowledgments: This work has been partially supported by the Fundação para a Ciência e a 

Tecnologia (F CT), Portugal, and its PCDT (F EDER funded) programme. TFSS is grateful to F CT 

for a PhD grant (no. SFRH/BD/48087/2008). 

References 

[1] C. Pettinari, Scorpionates II: Chelating Borate Ligands - Dedicated to Swiatoslaw Trofimenko, 

Imperial College Press, World Scientific Pub., 2008. 

[2] a) T.F.S. Silva, K.V. Luzyanin, M.V. Kirillova, M.F. Guedes da Silva, L.M.D.R.S. Martins, 

A.J.L. Pombeiro, Adv. Synth. Catal., 2010, 352, 171. b) T.F.S. Silva, E.C.B.A. Alegria, 

L.M.D.R.S. Martins, A.J.L. Pombeiro, Adv., Synth. Cat., 2008, 350, 706. c) R. Wanke, P. 

Smolenski, M.F.C. Guedes da Silva, L.M.D.R.S. Martins, A.J.L. Pombeiro, Inorg. Chem., 2008, 

47, 10158. 



Electrochemical behaviour of novel scorpionate and pyrazole 

dioxovanadium complexes 

Telma F.S. Silva, 1 Konstantin V. Luzyanin, 1 Luísa M.D.R.S. Martins, 1,2 

Armando J.L. Pombeiro 1 

1 Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais, 1049- 

001 Lisboa, Portugal. 2 Área Departamental de Engenharia Química, ISEL, R. Conselheiro Emídio 

Navarro, 1959-007 Lisboa, Portugal. 

tsilva@dem.isel.ipl.pt 

The coordination chemistry of vanadium, in particular with multidentate ligands, is 

receiving much attention namely on account of its involvement in various biological and 

catalytic processes, and the search for novel V complexes with pharmacological and 

catalytic significance is a matter of a high current interest. 1 

In view of the significance of V-chemistry with poly(pyrazolyl)borate ligands towards 

mimicking biocatalytic behaviours and also in pursuit of our interest on transition metal 

complexes bearing scorpionate ligands, we have embarked upon the syntheses of 

oxovanadium complexes with such ligands and with those of the related 

tris(pyrazolyl)methane family, 2 namely the dioxovanadium(V) complexes [VO 2 (3,5- 

Me 2 Hpz) 3 ][BF 4 ] 1 (pz = pyrazolyl), [VO 2 {SO 3 C(pz) 3 ] 2, [VO 2 {HB(3,5-Me 2 pz) 3 }] 3 or 

[VO 2 {HC(pz) 3 }][BF 4 ] 4, and the oxovanadium(IV) complex [VO{HB(pz) 3 }{H 2 B(pz) 2 }] 

5. 

We are now reporting the results of our study of 

the redox behaviour, by cyclic voltammetry and 

controlled potential electrolysis (at a platinum 

electrode, 25 ºC, in a 0.2 M 

[ n Bu 4 N][BF 4 ]/CH 2 Cl 2 or DMSO solution), of the 

obtained vanadium complexes, which allowed us 

to get an insight into the net electron-donor 

ability of such ligands and in the redox 

V(V)/V(IV) or V(IV)/V(III) interplay, essential 

for the vanadium versatility as a catalyst. 

Acknowledgments: This work has been partially supported by the Fundação para a Ciência e a 

Tecnologia (F CT), Portugal, and its PPCDT (F EDER funded) programme. TFSS is grateful to 

F CT for a PhD grant (no. SFRH/BD/48087/2008). 

References 

[1] A.S. Tracey, G.R. Willsky, E.S. Takeuchi, Vanadium Chemistry, Biochemistry, 

Pharmacology and Practical Applications, CRC Press, 2007. 

[2] Silva, T.F.S.; Luzyanin, K.V.; Kirillova, M.V.; Guedes da Silva, M.F.; Martins, L.M.D.R.S.; 

Pombeiro, A.J.L., Adv. Synth. Catal., 2010, 352, 171. 



Electrochemical behaviour of para-substituted 

3-(phenylhydrazo)pentane-2,4-diones 

Maximilian N. Kopylovich, a K amran T. Mahmudov, a M. Fátima C.Guedes da 

Silva, a,b Luísa M. D. R. S. Martins, a,c Maxim L. Kuznetsov, a Telma F. S. Silva, a 

João J. R. Fraústo da Silva, a Armando J. L. Pombeiro a 

a Centro de Química Estrutural, Complexo I, IST, TU Lisbon, Av. Rovisco Pais, 1049001 Lisboa, 

Portugal. b Universidade Lusófona de Humanidades e Tecnologias, ULHT Lisbon, Campo Grande 

376, 1749-024 Lisboa, Portugal. c Área Departamental de Engenharia Química, ISEL, R. 

Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal 

kamran_chem@mail.ru 

The electrochemical behaviour of unsubstituted 3-(phenylhydrazo)pentane-2,4-dione 

(H L 1 ) and its para-substituted chloro (H L 2 ), carboxy (H L 3 ), fluoro (H L 4 ) and nitro 

species (H L 5 ) were studied using cyclic voltammetry and the results were interpreted by 

theoretical calculations at the DFT/HF hybrid level. The substituent at the aromatic ring 

has a stronger influence on the oxidation potential (E p/2 ox ) than on the reduction one 

(E p/2 Red ), in accord with the HOMO and LUMO compositions, the former with an 

important contribution of the aromatic component and the latter being essentially 

localized at the other part of the molecule. Theoretical studies can account for the 

irreversibility of the redox processes and allow to propose conceivable mechanisms 

involving single-electron anodically induced dimerization and two-electron cathodically 

induc 

Trends between the Hammett's p , normal n p, inductive I , resonance R , 

negative p and positive p 

+ 

polar conjugation and Taft's o p substituent constants and 

reduction and oxidation potentials were recognized. A good fit was found for p . 

p 

 

2 

E p/2 

ox 

/ V 

1.4 

1.0 

0.6 

0.2 

 

 

p = 4.55E ox p/2 r 2 = 0.903, n = 5 

 

 

 

1.05 1.10 1.15 1.20 1.25 1.30 

Fig.1- Plot of the p substituent constant versus E p/2 

ox 

for HL 1-5 . 

The obtained correlations or trends should be used to tune various properties of 

HL such as acidity, coordination ability, biological activity, etc., what can be of 

interest for both fundamental studies and practical applications. 


Technology (F CT 



Redox behavior of dinuclear iron(II) and ruthenium(II) 

complexes as potential molecular wires 

A. Catarina Sousa 1 , Vanda Pacheco 1 , M. Paula Robalo 1,2 

1 Área Departamental de Engenharia Química, Instituto Superior de Engenharia de Lisboa, Instituto 

Politécnico de Lisboa, R. Conselheiro Emídio Navarro, 1, 1959-007, Lisboa, Portugal; 

2 Centro de Química Estrutural, Complexo I, IST, Av. Rovisco Pais, 1049-01 Lisboa, Portugal 

acsousa@deq.isel.ipl.pt 

Molecular wires comprising mixed-valence bimetallic units or remote redox-active 

organometallic groups linked by conjugated bridging organic chains could be exploited 

in molecular electronics and optoelectronic devices 1 . 

e - 

Metal centre 

Organic spacer 

Metal centre 

Our recent work in this field has been the design and development of transition metal 

complexes, with a special emphasis on the half sandwich iron(II) and ruthenium(II) 

compounds, with nitrile or alkynyl organic ligands, which can be used as building 

blocks of molecular wires, allowing electronic communication between redox-active 

terminal end groups through delocalized bonds. 

Since the cyclic voltammetry can be used as a tool to evaluate the efficiency of this 

electronic interaction between the metal centres, we report in this communication, the 

electrochemical behavior of several mono and dinuclear iron(II) and ruthenium(II) 

-CH 2 - C- 

C(H)=C(H)- -C 6 H 4 - 

([CpFe(dppe)] + , [CpFe(CO) 2 ] + , [CpRu(dppe)] + . 

The cyclic voltammograms of the studied compounds were performed in 1 x 10 -3 M 

dichloromethane and acetonitrile solutions, using tetrabutylammonium hexafluorophosphate 

(TBAPF 6 ) as supporting electrolyte (0.2 M) at different scan rates (20-1000 

mV/s). 

The obtained results are discussed in terms of the electron richness of the metal centres 

and electronic properties of the organic ligands upon coordination, which can be related 

to the metal-to-ligand bonding ability. Furthermore, the ability of the different organic 

spacers in the electronic communication between the metal centres was also evaluated. 

Acknowledgements: We thank Fundação para a Ciência e a Tecnologia (F CT/MCTES) for partial 

financial support (project PTDC/QUIM/65379/2006) and IPL (project IPL/16/2003). 

References 

[1] a) Paul, F., Lapinte, C., Coord. Chem. Rev., 1998, 178-180, 431-509; b) Ceccon, A. Santi, S., 

Orian, L., Bisello, A., Coord. Chem. Rev., 2004, 248, 683-724. 



Investigation of 4-dimethoxymethyl- and 4-formyl-substituted 

1,4-dihydropyridine redox reactions. 

Anna Lielpetere, Inguna Goba, Baiba Turovska 

Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, Latvia 

anna.lielpetere@gmail.com 

A little attention has yet been paid to the chemistry of formyl-substituted 

dihydropyridines [1,2] and there are no electrochemical investigations of them. In the 

work the synthesis and anodic oxidation of symmetrical and asymmetrical substituted 

1,4-DHP bearing chemically active formyl- or its protective acetal group has been 

studied. In acetonitrile the anodic oxidation of 

H R 

H R 

X 

X 

Y 

X the studied compounds proceed in one 

irreversible step Figure 1, Figure 2. During the 

H C N C H H 3 

3 

3 C N C H 3 

controlled potential electrolysis all studied 

H 

H 

compounds lost the substituent at C-4, while the 

X = C N, C O C H 3 , C O O C H 3 X = C O C H 3 , C O O C H 3 ; Y = C N 

products of their chemical oxidation 

R = C H(O C H 3 ) 2 , C H O R = C H(O C H 3 ) 2 , C H O 

(2,3-dicyano-5,6-dichloro-p-benzoquinone) were 

corresponding 4-substituted pyridines. 

N C 

H 3 C O 

H 

O C H 3 

C H 

C O C H 3 

-e 

H 3 C N C H 3 

H 

H 3 C O O C H 3 

H C H 

H 

N C 

C O C H 3 N C 

C O C H 3 

. + + 

H 3 C N C H 3 

H 3 C N C H 3 

H 

Fig. 1. Anodic oxidation of 1,4-DHP 

Fig. 2. Anodic oxidation of 1,4-DHP 

in MeCN/0.1 M NaClO 4 in MeCN/0.1 M NaClO 4 

H 

ClO 4 

- 

N C 

H 3 C 

H 

. + 

N 

H 

O 

C H 

C O C H 3 

.. .. 

C H 3 

-e 

N C 

H 3 C 

H 

N 

H 

O 

C H 

C O C H 3 

C H 3 

H 3 C O O C H 3 

H C H 

N C 

C O C H 3 

.. 

H 3 C N C H 3 

H 

N C 

H 3 C 

O 

H C H 

C O C H 3 

.. 

N C H 3 

H 

4-Formyl-substituted 1,4-DHP are stable compounds at the room temperature, while in 

the solution aldehyde group at C-4 in dihydropyridine molecule could easy be oxidized 

to the acid or reduced with subsequent intramolecular condensation with the substituent 

at C-3 or C-5. 

Acknowledgments: We are grateful to the Latvian Science Foundation (Grant 2010_09.1558) for 

their support of this research. 

References 

[1] Grau M. A., Illescas B., Martinez Torres M. L., Fernandez-Gadea J., Martin N. Tetrahedron 

Letters, 2002, 43, 4133. 

[2] Li A. H., Moro S., Melman N., Ji X. D., Jacobson K. A. J. Med. Chem., 1998, 41, 3186. 



Redox properties of antitumor active organotin(I V) complexes 

containing 1-(4-chlorophenyl)-1-cyclopentanecarboxylato 

ligands 

Elisabete C.B.A. Alegria, a,e Xianmei Shang a,b , Xianggao Meng c , 

Qingshan Li d , M. Fátima C. Guedes da Silva, a, f Armando J.L. Pombeiro a 

a Centro de Química Estrutural, IST, TU Lisbon, Av. Rovisco Pais, 1049001 Lisbon, Portugal. 

b Tongji School of Pharmacy, Huazhong University of Science and Technology, 13 Hangkong 

Road, Wuhan 430030, China. 

c Department of Chemistry, Central China Normal University, Wuhan, 430079, China. 

d School of Pharmaceutical Science, Shanxi Medical University, Taiyuan, 030001,China. 

e Área Departamental de Engenharia Química, ISEL, R. Conselheiro Emídio Navarro, 1959-007 

Lisboa, Portugal. 

f Universidade Lusófona de Humanidades e Tecnologias, Av. Campo Grande, 376, 1749-024 

Lisboa, Portugal 

ebastos@deq.isel.ipl.pt 

Investigations on metal-based drugs have become very popular 

with ruthenium(III) and platinum(IV) compounds [1], since various metal-complexes 

exist in inert high oxidation states in aqueous solution [e.g., Ru(III), Pt(IV)], and are 

more labile in reduced oxidation states [e.g., Ru(II), Pt(II)]. It is widely believed that 

reduction processes may influence the anticancer activity of many Pt(IV) and Ru(III) 

complexes [2,3]. 

Encouraged by the reduction mechanism of other metal-based antitumor complexes like 

Pt(IV) or Ru(III) and considering the widely studied and reviewed [4] anticancer activity 

of organotin(IV) compounds, we are interest to find how reduction potentials are related 

with the biological activity of organotin(IV) complexes. 

We now report the electrochemical behaviours, at a Pt electrode and in aprotic media of 

the organotin(IV) complexes [Me 2 Sn(L) 2 ] (1), [Et 2 Sn(L) 2 ] (2), [ n Bu 2 Sn(L) 2 ] (3), 

[ n Oct 2 Sn(L) 2 ] (4), [Ph 2 Sn(L) 2 ] (5) and [PhOSnL] 6 (6), resulting from reaction of 1-(4- 

chlorophenyl)-1-cyclopentanecarboxylic acid (H L) with the corresponding diorganotin 

oxide or dichloride. Such behaviours are discussed in terms of the electronic properties 

of the Sn centres and their ligands. Possible correlation between the redox potential and 

in vitro cytotoxic activities of those six complexes against four different cell lines [a 

human promyelocyticfina leukemic cell line (HL-60), a human hepatocellular carcinoma 

cell line (Bel-7402) and a human nasopharyngeal carcinoma cell line (KB)] will be 

discussed. 

Acknowledgments: This work has been supported by the Foundation for Science and Technology 

(F CT) (grant No. SFRH/BPD/44773/2008) and the IPL/41/2003 project. 

References 

[1] E. Reisner, V.B. Arion, B.K. Keppler, A.J.L. Pombeiro, Inorg. Chim. Acta, 2008, 361, 1569. 

[2] E. Reisner, V.B. Arion, A. Eichinger, N. Kandler, G. Geister, A.J.L. Pombeiro and B.K. 

Keppler, Inorg. Chem., 2005, 44, 6704-6716. 

[3] A.J.L. Pombeiro, Eur. J. Inorg. Chem., 2007, 1473. 

[4] L. Pellerito, L. Nagy. Coord. Chem. Rev. 2002, 224, 111. 



Synthesis and electrochemical studies of molecular wires 

based on dinuclear Pd and Ru OPE and O T E rods. 

João Figueira 1 , José Carlos Mesquita 1 , Kari Rissanen 2 , João Rodrigues 1 

1 Centro de Química da Madeira, LQCMM/MMRG, Universidade da Madeira, 

Campus da Penteada, 9000-390 Funchal, PORTUGAL 

2 Nanoscience Center, Department of Chemistry, University of Jyväskyla, 

P.O. Box 35, 40014 JYU, FINLAND 

jfig@uma.pt 

Highly conjugated molecules have been of great interest for their potential applications 

in fields such as nanoelectronics [1] or optoelectronics [2]. As such, organometallic rods 

with robust and redox capable metal centers can offer excellent properties and attractive 

advantages over their organic counterparts as well as the currently available wires by 

increasing energy throughput and decreasing production costs. Organic bridges, such as 

OPE (oligo(phenylene ethynelene)s) and OTE (oligo(thiophenylene ethynelene)s) 

derivatives [3] can be used to tune the electronic communication between metal centers. 

In this work we present the synthesis and the CV studies of a family of trans- 

[Pd(PEt 3 ) 2 Cl 2 ] and trans-[RuCl 2 (dppe) 2 ] rods based on these OPEs (1,4-diethynyl-2,5- 

dialcoxybenzene and 4,4'-(2,5-dialcoxy-1,4-phenylene)bis(ethyne-2,1-diyl)bis(ethynylbenzene) 

derivatives) and OTEs (2,5-bis(4-ethynylphenyl)thiophene derivatives) bridges 

as potential molecular wires. 

Figure 1. Cyclic voltammogram of the Ru rod of 1,4-diethynyl-2,5-heptoxybenzene at 

100mV s -1 vs Ag/AgCl in CH 2 Cl 2 with NBu 4 PF 6 0.1M. 

Acknowledgments: We gratefully acknowledge the support of F CT trough NMR and MS 

Portuguese Networks (REDE/1517/RMN/2005, REDE/1508/REM/2005), Pluriannual base funding 

(QUIM-Madeira-674), JF Ph.D. grant (SFRH/BD/29325/2006) and Research Project 

PTDC/CTM/098451/2008. CS Madeira is also gratefully acknowledged for their support. 

References: 

[1] a) Tour, M. J., Molecular Electronics, Commercial Insights, Chemistry, Devices, Architecture 

and Programming. Singapore: World Scientific Publishing Co. Pte. Ltd., 2003; b) Rodrigues, J.; 

An Organometallic Approach to Molecular Electronics, Proceedings of FAME EU FP6 

Network of Excellence, Funchal, Portugal, 2007, 247. 

[2] Ornelas C.; Gandum, C.; Mesquita, J.; Rodrigues, J.; Garcia, M. H.; Lopes, N.; Robalo, M. P.; 

Nättinen, K.; Rissanen, K.; Inorg. Chim. Acta, 2005, 358, 2482. 

[3] Figueira, J.; Rodrigues, J.; Russo, L.; Rissanen, K., Acta Cryst., 2008, C64, o33. 



Electrochemical studies on luminescent bis-calix[4]arenebased 

poly(p-phenylene ethynylene) copolymers 

M. Paula Robalo, Hugo S. Pinto, Alexandra I. Costa, José V. Prata 

Área Departamental de Engenharia Química and Centro de Investigação de Engenharia Química e 

Biotecnologia, Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, 

R. Conselheiro Emídio Navarro, 1, 1959-007, Lisboa, Portugal. 

mprobalo@deq.isel.ipl.pt 

Considerable research efforts have been directed in the last decade towards the 

development of a diversity of conjugated polymers with tailored electronic and 

photophysical properties, owing to their potential application in electroluminescent 

devices (EL), such as photovoltaic cells and polymer LEDs. Efficiency of EL devices is 

intimately related to the oxidation and reduction potentials of the emitting polymer 

layers and cyclic voltammetry (CV) is a powerful technique to evaluate this efficiency. 

In the present communication, we report on the electrochemical studies of several 

related poly(p-phenylene ethynylene) (p-PPE) copolymers: C A L I X-p-PPE [1], 

containing non-substituted phenylene ethynylene groups linking the bis-calix[4]arene 

units (1) and the same incorporating 2,5-dialkoxy-p-phenylene ethynylene linkers [2] 

with variable chain lengths (2a-c). Some structurally related monomers and model 

compounds were also studied (e.g. tetrapropyl-calix[4]arene, end-capped biscalix[4]arene 

and T BP-p-PPE) in order to correlate the redox processes found in the 

copolymers with the different structural components. 

The electrochemical data of the polymers and related model compounds was also used 

to determine the HOMO/LUMO energy levels as well their electrochemical bandgaps 

(E g EC ). 

III 

O O O O 

C 3 H 7 C 3 H 7 C 3 H 7 

R 1 

C 3 H 7 C 3 H C 7 3 H 

n 

7 

O O O O R 2 

I 

II 

1: R 1 = R 2 = H 

2: R 1 = R 2 = OR 3 

a R 3 = OCH 2 CH 2 CH 3 

b R 3 = OCH 2 (CH 2 ) 4 CH 3 

c R 3 = OCH 2 (CH 2 ) 8 CH 3 

2,5 

2 

1,5 

1 

0,5 

0 

E vs SCE (V) 

-‐0,5 

-‐1 

-‐1,5 

Figure 1 Cyclic voltammogram for C A L I X-p-PPE (1) in 

dichloromethane at 100 mV.s -1 . 

-‐2 

Acknowledgments: We thank Fundação para a Ciência e a Tecnologia/MCTES for partial 

financial support (project PTDC/QUIM/66663/2006). A. I. Costa thanks Instituto Superior de 

Engenharia de Lisboa for a doctoral fellowship.. 

References 

[1] Costa, A. I.; Ferreira, L.F.V.; Prata, J.V., J. Polym. Sci. Part A: Polym. Chem., 2008, 46, 6477. 

[2] Pinto, H.S., MSc thesis, ISEL, 2010. 



Ruthenium(II) and Iron(II) Complexes bearing 

low band-gap thiophenic ligands as possible N L O switches 

Tiago J. L. Silva 1 , Paulo J. G. Mendes 2 , M. Helena Garcia 1 , 

M. Paula Robalo 3 

1 Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-001 Lisboa, Portugal 

2 Centro de Química de Évora, R. Romão Ramalho 59, 7000-671 Évora, Portugal 

3 

ADEQ/ISEL, R. Conselheiro Emídio Navarro, 1, 1959-007 Lisboa 

tjsilva@fc.ul.pt 

Over the past decade, there was growth of interest in discovering new conducting 

molecules due to their potential applications in electrochromic devices, sensors, OLED's 

and more recently molecular switches. Non-Linear Optics (NLO) phenomenons, namely 

Second-Harmonic Generation (SHG), is one of the recently topics in molecular 

 

electrochemically changed in or 

switch, upon a redox process. 

Monocyclopentadienyliron (II) and ruthenium (II) complexes, combined with thiophene 

ues and 

have been widely studied for NLO [2]. Regarding the switching properties, oxidation in 

the transition metal, from M (II) to M (III) (M=Fe, Ru), can drastically reduce the NLO 

properties of these molecules and therefore it provides a way to electrochemically 

onoff 

In this communication, monocyclopentadienyliron (II) and ruthenium (II) complexes 

bearing thiophene ligands (Figure 1) with low band-gaps will be electrochemically 

tested as possible molecules for NLO switching. The electrochemical results will be 

correlated with spectroscopic data and the NLO properties predicted by DFT 

calculations, in order to anticipate the potentialities of the new compounds as molecular 

switches. 

Figure 1 Elucidating picture of the studied ruthenium complexes 

Acknowledgments: We thank to COMPETE/F EDER for financial support (F COMP-01-0124- 

F EDER-007433). 

References 

[1] Coe, Benjamin, Acc. Chem. Res., 2006, 39, 383 

[2] a) Garcia, M. H., et al, J.Organomet. Chem., 2009, 694, 433. b) Mendes, P. et al, J. Mol. 

Struct.: THEOCHEM, 2010, 946, 33. c) Mendes, P. et al, J. Mol. Struct.: THEOCHEM, 2009, 

900, 110. 



Electrocrystallization of (D T-T T F) 2 [M(mnt) 2 ] on 

microelectrodes 

Rafaela A. L. Silva, 1 Mónica Afonso, 1 Manuel Matos 2,3 , Dulce Belo, 1 

Manuel Almeida 1 

1 Dept. Chemistry, ITN / CFMCUL Estrada Nacional 10, P-2686-953 Sacavém, Portugal 

2 

IT, Av. Rovisco Pais, P-1049-001 Lisboa, Portugal, 

3 ISEL, Av. Emídio Navarro, P-1959-007 Lisboa, Portugal 

rafaela@itn.pt 

The charge transfer salts based on the organic donor dithiotetrathiafulvalene (DT-TTF) 

and transition metal bis-maleonitrile-dithiolate M(mnt) 2 with M =Au, Ni, Cu, Pt and Pd, 

are members of a general family of compounds with formula (DT-TTF) 2 [M(mnt) 2 ] 

presenting strongly paired stacks of partially oxidized donor molecules (DT-TTF) + 2 [1]. 

The compounds of this family with diamagnetic anions (M=Cu, Au) have attracted 

special interest because they were the first examples of organic spin ladder systems 

[2,3]. 

The study of these materials requires both high quality large single crystals and 

techniques able to characterize the electronic properties in rather small samples. 

Crystals of these compounds can be obtained by electrocrystallization conditions typical 

for charge transfer salts; the DT-TTF donor in a organic solvent is electrochemically 

oxidized in the presence of [M(mnt) 2 ] - anions to form the compound as crystals 

growing on the anode. 

In order to obtain large single crystals of high quality we have performed a study aimed 

at to optimize the electrocrystallization conditions. Using dichloromethane solutions and 

Pt as electrodes we were able to obtain good single crystals as large as 5x1x0.1 mm 3 . 

In order to make possible the measurement of electrical transport properties in smaller 

crystals of these compounds it was developed a technique of electrocrystallization on 

micropatterned electrodes. This technique using pulsed currents was able to provide 

small crystals directly connected to microelectrodes which can be used directly to 

electrical measurements. 

Acknowledgments: Work supported by F CT under contract PTDC/QUI-QUI/101788/2008. 

References 

[1] Ribera, E.; Rovira, C.; Veciana, J.; Tarrés, J.; Canadell, E.; Rousseau, R.; Molins, E.; Mas, M.; 

Schoefel, J-P.; Pouget, J.-P.; Morgado, J.; Henriques, R. T.; Almeida, M.; Chemistry an 

European Journal, 1999, 5, (7) 2025-2039. 

[2] Rovira, C.; Veciana, J.; Ribera, E.; Tarrés, J.; Canadell, E.; Rousseau, R.; Mas, M.; Molins, E.; 

Almeida, M.; Henriques, R. T.; Morgado, J.; Schoefel, J-P.; Pouget, J.-P.; Angewandte Chemie, 

International Edition in English, 1997, 36, 2324-2326. 

[3] Ribas, X.; Mas-Torrent, M.; Pérez-Benítez, A.; Dias, J. C.; Alves, H.; Lopes, E. B.; Henriques, R. 

T.; Molins, E.; Santos, I. C.; Wurst, K.; Foury-Leylekian, P.; Almeida, M.; Veciana, J.; Rovira, 

C.; Organic spin-Advanced Functional Materials, 2005, 15, 1023- 

1035. 



An electrochemical study of Schiff-base oxovanadium(I V) 

complexes 

F . Bishehsari, A. Rouhollahi, S. Rayati 

#4, No.72, Sartip Fakoori Ave., Kargar Shomali Str., Tehran, Iran 

Faranak.bsh@gmail.com 

The interest in coordination chemistry of vanadium has increased because of its catalytic 

and medicinal importance [1-2]. The electrochemical behavior of three newly 

synthesized Schiff base VO(IV) complexes with electron donating groups were 

investigated, in acetonitrile (An) in the presence of tetrabutylammonium perchlorate as 

supporting electrolyte at the surface of GC electrode by cyclic voltammetry and 

chronopotentiometry (Figure 1). 

For all the VO(IV) compounds, one reversible oxidation wave has been found and the 

diffusion coefficients (D) were obtained. The effect of scan rate was evaluated. 

R = Me, X = H, Y = OMe 

Figure 1 - Cyclic voltammogram for [VOR 1 ] = 

2.0010 -6 mol cm -3 at different sweep rates 

(0.01, 0.05, 01, 0.2 Vs -1 ) 

References 

[1] Butler, A.; Clague, M. J.; Meister, G. E. Chem. Rev, 1994, 94, 62 

[2] Crans, D. C. J. Inorg. Biochem, 2000, 80, 123. 



Authors Index 



A 

Abrantes, L.M. OC 1 

Afonso, M. OC 6 PE 15 

Alegria, E.C.B.A. OE 2 PE 11 

Almeida, I. OC 4 

Almeida, M. OC 6 PE 15 

Almeida, M.G. OB 4 

Alves, S. PA 1 

Anunciação, M.F. OB 1 

Ascensão, C. PA 4 

Avilés, F.X. PB 10 

B 

Ball, Sarah OA 3 

Barrera-Niebla, M.J. OC 2 OC 5 

Barros, A.A. OB 1 PB 1 

Barros, M.C.F. PA 5 

Bastos, A.C. PB 11 PD 2 

Becker, D. OA 8 

Belo, D. PE 15 

Belo, M.C. PD 5 

Benedicto, E.C.P. PA 10 

Benimeli, M.J. PA 7 

Benjumea, D.M. PA 8 

Bento, F. PB 4 PB 5 

Bento, M.F. KN 4 

Bettencourt, A.P. PE 3 

Bettencourt, P. PB 4 PB 5 

Bishehsari, F. PE 16 

Blandón, L. PA 8 PA 9 

Bláquez, L.C. PB 6 

Blasco-Tamarit, E PD 9 

Blásquez, M. PL 2 PC 3 PC 4 

Bonastre, J. PA 7 PD 4 

Borges, S. PB 11 

C 

Calvet, T. PB 10 

Calvisi, M. PD 6 

Campos , M. OA 3 

Carvalho, M.A. PE 3 

Carvalho, M.D. PA 6 PD 3 

Carvalho, M.F.N.N. OE 4 



Cascalheira, A.C. PB 7 

Cases, F. PA 7 PD 4 

Castela, A.S. OD 2 

Catarino, M.A. PD 5 

Chhaganlal, M.N. PB 9 

Ciríaco, L. PA 2 PA 3 PA 4 

Ciro, G. PA 8 

Coelho, J.C. PD 3 

Conceição, A. OA 4 

Cordeiro, J.R. OB 5 

Correia, C. PE 3 

Correia, J.P. OC 1 

Costa, A.I. PE 13 

Costa, D. O. PA 11 

Cruz, M. PB 1 

D 

Dias, C.B. PD 2 

Duarte, R.G. OA 5 OD 2 

Duval, E. PA 7 

E 

Esteso, M.A. PA 5 PA 11 

Eugénio, S. PD 8 

F 

Fernandes, J.S. PL 3 

Fernandes, S.M.A. PC 1 

Fernandes, T.A. OE 4 

Fernández, J. PD 4 

Ferreira, A.A. PD 2 

Ferreira, M.G. OD 2 

Ferreira, M.G.S. KN 3 OA 5 OD 1 PD 2 PD 5 PD 7 

Ferron, C.C. OE 1 PE 2 

Figueira, J. PE 12 

Filipe, R. OA 2 

Fonseca, I.T.E. PD 2 PD 3 

Font-Bardia, M. PB 10 

Freire, C. KN 1 

Freire, L. PD 5 

Freitas, M KN 2 

G 

Galvão, A.M. OE 4 

García, L. PA 9 



Garcia, M.H. PB 9 PB 10 PE 4 PE 14 

García-Antón, J. PD 1 PD 9 

García-García, D.M. PD 9 

García-Raya, D. PL 2 

Geraldo, M.D. KN 4 PB 4 PB 5 

Gil, D.M.A. OB 2 

Gil, E.P. PB 6 

Goba, I. PE 10 

Godinho, M.I. PD 5 

Gomes, A. PA 6 

Gomes, F. PE 3 

Gonçalves, E. OA 4 

Gonçalves, L.M. OB 1 PB 1 

Gonçalves, M.L. PA 1 PB 3 

González-Cano, R.C. PC 3 

González-Granados, Z. PC 4 

González-Mesa, G. PD 6 

Gruber, J. OB 5 PB 2 

H 

Haukka, M. OE 3 

He, M. PE 2 

Hernández, M.R.G. OC 2 OC 5 

Hernández, V. OE 1 PE 2 

Hernández-Luis, F. PA 8 PA 9 

I 

Ibáñez-Ferrándiz, M.V. PD 9 

Ilharco, L.M. OA 5 

Inestrosa, E.P. OE 1 

Isaacs, H.S. OD 1 

Jorge, M.E.M. PA 6 

K 

Karmali, A. OB 3 PB 12 

Kopylovich, M.N. OE 3 PE 8 

Kuznetsov, M.L. OE 2 PE 8 

L 

Lamaka, S.V. OD 1 PD 7 

Leitão, R.E. OA 2 

Leiva-García, R. PD 1 

Li, Q. PE 11 

Li, R.W.C. OB 5 PB 2 

Lielpetere, A. PE 10 



Lippi, Renata OB5 PB 2 

Lobo, V.M.M. PA 5 

Lopes, A. KN 5 PA 2 PA 3 PA 4 

López, M.L. PB 8 

Lorenzo, J. PB 10 

Ludvík, J. PL 5 

Luzyanin, K.V. OE 3 PE 7 

M 

Madueño, R. PL 2 PC 3 PC 4 

Mahmudov, K.T. OE 3 PE 8 

Manso, J. PB 11 

Marques, A. OC 7 

Marques, J. PB 4 PB 5 

Martins, F. OA 2 PB 11 

Martins, L.M.D.R.S. OE 2 PE 5 PE 6 PE 7 PE 8 

Matos, M.J. OB 3 OC 6 PB 12 PE 15 

Medina, D.M.G. OC 2 OC 5 

Melato, A.I. OC 1 

Mellado, J.M.R. PE 1 

Mendes, P.J.G. PE 4 PE 14 

Meng, X. PE 11 

Mérida, L.C.F. OC 2 OC 5 

Mesquita, J.C.A. PC 1 PE 12 

Miranda, V. PB 11 

Molina, J. PA 7 PD 4 

Montemor, M.F. OD 1 PD 5 PD 7 

Montenegro, J.M. OE 1 

Montoya, M.R. PE 1 

Morais, T.S. PB 10 

Morales, M.G. PB 6 

Moreira, L. OA 2 

Moreno, V. PB 10 PB 9 

Morín, M.J.G. OC 2 OC 5 

Moura, I. PB 3 

Moura, J.J.G. OB 4 PB 3 

Muñoz-Portero, M.J. PD 1 

N 

Nabais, C. PA 1 

Navarrete, J.T.L. OE 1 PE 2 

Neto, M.M.M. PD 2 

Nieto, F.J.R OA 8 

Niu, W. PE 2 

Nunes, N. OA 2 

Núñez-Vergara, Luis J. PB 8 



O 

Oliveira, C. OC 3 PC 2 

Oliveira, M.C. PA 10 

Oliveira, R. PB 4 PB 5 

P 

Pacheco, J.G. OB 1 

Pacheco, J.P. PB 1 

Pacheco, M.J. PA 2 PA 3 PA 4 

Pacheco, V. PE 9 

Paiva, T.I. KN 6 

Pang, S.C. OA 7 

Pauleta, S.R. PB 3 

Pecoraro, E. PB 12 

Pereira, F. OB 4 

Pereira, M.I.S. PA 6 

Pérez, M. PD 6 

Pettigrew, G.W. PB 3 

Pimpão, M. OB 4 

Pineda, T. PL 2 PC 3 PC 4 

Pintado, S. PE 1 

Pinto, H.S. PE 13 

Pombeiro, A.J.L. OE 2 OE 3 PE 5 PE 6 PE 7 PE 8 PE 11 

Potter, R. OA 3 

Prata, J.V. PE 13 

Proença, M.F. PE 3 

Q 

Quaresma, S. PD 8 

Quereshi, M.S. OB 6 

R 

Ramadas, D. PB 7 

Rangel, C.M. KN 6 PA 6 PD 8 

Rayati, S. PE 16 

Rebelo, M.J.F. OB 2 

Rego, A.M. PC 2 

Rego, A.M.B. OA 5 

Rego, R. OC 3 PC 2 

Reis, M. OA 2 

Ribeiro, A.C.F. PA 5 PA 11 

Río, A.I. PA 7 PD 4 

Rissanen, K. PE 12 

Robalo, M.P. PB 9 PB 10 PE 4 PE 9 PE 13 PE 14 



Rocha, M.M. OB 3 

Rocha, R. OA 1 

Rodrigues, A.S. PA 2 

Rodrigues, J. PE 12 

Rodrigues, J.A. PB 1 

Rodrigues, J.M. OB 1 

Rouhollahi, A. PE 16 

S 

Sá, A.I. PD 8 

Salgado, J.R.C. OA 5 

Sánchez, N. PA 9 

Santos, A. C. PA 11 

Santos, A.M. PE 4 

Santos, C.I.A.V. PA 5 PA 11 

Santos, M.M.C. PL 4 PA 1 PB 3 

Santos, S. PB 11 

Sarmento, M.J. PB 11 

Shang, X. PE 11 

Silva, J.J.L.F PE 8 

Silva, M.F.C.G. OE 2 PE 8 PE 11 

Silva, N.A.F. OB 3 PB 12 

Silva, R.A. KN 6 PA 6 

Silva, R.A.L. OC 6 PE 15 

Silva, T.F.S. PE 6 PE 7 PE 8 

Silva, T.J.L. PE 4 PE 14 

Silveira, C.M. OB 4 

Simões, A.M.P. OC 7 OD 3 PD 5 

Sirajuddin, OB 6 

Snihirova, D. PD 7 

Soares, C.O. PA 6 

Sobreira, S. PA 3 

Sousa, A.C. PE 9 

Sousa, P.M.P PB 3 

Squella, J.A. PB 8 

T 

Takahashi, E.S. OB 5 

Taryba, M.G. OD 1 PD 7 

Teijeiro, C. PA 11 

Teixeira, C. OA 6 PA 10 

Teixeira, J.M.G. PC 1 

Turovska, B. PE 10 



V 

Valente, A. PB 10 

Valente, I.M. OB 1 PB 1 

Vázquez, M.V. PA 8 PA 9 

Ventura, M.C. PB 11 

Vercelli, B. OE 1 PE 2 

Viana, A.S. OC 4 PB 7 

Vilar, R. PD 8 

Visintin, A. OA 8 

W 

Wanke, R. PE 5 

Wee, B.H. OA 7 

Z 

Zanello, P. PL 1 

Zheludkevich, M.L. KN 3 PD 2 

Zotti, G. OE 1 PE 2 


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