ISMSC 2007 - Università degli Studi di Pavia

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Molecular inclusion of organometallic sandwich complexes within hybrid cavitand-resorcin[4]arene receptors María Ángeles Sarmentero, a Guzmán Gil, a Pablo Ballester a,b . a Institute of Chemical Research of Catalonia (ICIQ), Avda. Països Catalans 16, 43007 Tarragona, Spain. b ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain. The confinement of guests within molecular vessels modifies their chemical behaviour. While included, guests can undergo reactions with significant rate enhancement and improved product selectivity.[1] On the other hand, the inclusion of redox-active guests, generally tends to slow down the kinetics of heterogeneous electron transfer reactions.[2] The complete encapsulation of cobaltocenium cations in non polar solvents has been achieved, mainly through cation- interactions, using non-covalent dimeric and hexameric capsules [3]. In this communication we describe the efficiency of simple and neutral hybrid cavitandresorcin[4]arene hosts for the molecular inclusion of positively charge organometallic sandwich complexes. The complexation process has been studied by 1 H-NMR and cyclic voltammetry techniques in organic solvents. The obtained results point out that the aromatic cavities present in the vase conformation of these receptors are electronically rich and capable of including organometallic sandwich cations by offering CH- and - interactions. Furthermore, the receptors show a remarkable size and charge selectivity in the molecular inclusion of the redox active guests. R 2 HN R 2 HN H 4 H 3 O H 9 O H1 H 5 Co R 2 HN H7 NHR 2 O O H10 R 1 H2 R 1 R 1 H6 R 1 =CH2CH3 R 1 H8 OH HO Ru O H 9 O R 2 =H; R 2 =COCH2CH3; NHR 2 NHR 2 PSB 55 [1] a) D. Fiedler, D. H. Leung, R. G. Bergman and K. N. Raymond, Acc. Chem. Res., 2005, 38, 349-358, b) M. Fujita, M. Tominaga, A. Hori and B. Therrien, Acc. Chem. Res., 2005, 38, 369-378. [2] C. M. Cardona, S. Mendoza and A. E. Kaifer, Chem. Soc. Rev., 2000, 29, 37-42. [3] a) D. Ajami, M. P. Schramm, A. Volonterio and J. Rebek, Jr., Angew. Chem. Int. Ed., 2007, 46, 242-244. b) I. Philip and A. E. Kaifer, J. Org. Chem., 2005, 70, 1558-1564. PSB 56 Subcomponent Exchanges in Self-Assembled Metallo-Organic Structures David Schultz, Jonathan R. Nitschke Department of Organic Chemistry, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva 4, Switzerland Using the principles of dynamic self-assembly we can build structures that are held together by two kinds of reversible bonds, covalent (C=N) and coordinative (NM) bonds, giving the possibility for dynamic sorting and substitution to occur. Selectivity imposed by metal ions was used to simplify dynamic combinatorial libraries of ligand subcomponents. We have shown that two different copper(I) complexes may self-assemble quantitatively from a common pool of subcomponents in each other’s presence.[1] Simultaneous templating involving the cooperative action of Cu I and Fe II allowed us to simplify an even more complex mixture of compounds.[2] Substitution of ligand subcomponents in such metallo-organic complexes is ruled by several factors that can be used to quantitatively and selectively transform one structure into another. The difference in pKA between the protonated amines was found to drive substitution by favoring the displacement of the protonated form of the weaker acid and the incorporation of the deprotonated form of the stronger acid.[4] Another way to drive subcomponent substitution is provided by the substituent electronic effects. We have shown the existence of a linear free energy relationship connecting the electron-donating character of an anilines’ para-substituent, as measured by the Hammett para parameter, to that aniline’s ability to compete with unsubstituted aniline to form imines.[3] These results allowed us to design the three-step transformation of a series of copper containing structures shown below. Electronic effects combined with the chelate effect allowed each step to proceed in predictably high yield. One interest of this experiment is that the topology of the product is changed at each step. O N N Cu N N + O NH 2 N N Cu N N + NMe 2 NMe 2 O O NH2 N N Cu N N + N N Cu N N + 99.5% NH2 97% H2N NH2 93% NMe2 N N Cu N N + [1] David Schultz and Jonathan R. Nitschke, Proc. Natl. Acad. Sci. USA 2005, 102, 11191- 11195 [2] David Schultz and Jonathan R. Nitschke, Angew. Chem. Int. Ed. 2006, 45, 2453-2456 [3] David Schultz and Jonathan R. Nitschke, J. Am. Chem. Soc. 2006, 128, 9887-9892 [4] David Schultz and Jonathan R. Nitschke, Chem. Eur. J. 2007, in press. O O
PSB 57 Removal of heavy metal ions from waste waters by molecular recognition technology Giuseppe Arena a , Elisa Longo a , Carmelo Sgarlata a , Richard A. Bartsch b , Dongmei Zhang b and Yanfei Yang b a Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, 95125 Catania, Italy b Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409-1061, USA Selective transport of metal ions through polymeric inclusion membranes (PIM), containing macrocyclic receptors, is an environmentally friendly and cost-effective technology for the removal of metal ions and pollutants from waste waters [1]. In this work, some calix[4]arene receptors, blocked in the cone conformation and functionalized with two N-(X)sulfonyl carboxamide groups on the lower rim, are proposed as carriers to be incorporated into PIMs. Preliminary studies of the complexing properties for related ligands, based on solvent extraction experiments, indicated a high complexation efficiency towards some heavy metal cations, such as Pb 2+ , Cd 2+ and Hg 2+ [2]. To obtain a better understanding of the complexing features of these systems, we have carried out a thermodynamic investigation by means of UV-Vis spectrophotometric titrations in acetonitrile. The data analysis, performed by a multivariate and multiwavelength treatment of the data, has allowed us to determine the complex species formed in solution, as well as their stability constants. The carriers with the best efficiency and selectivity have been incorporated into PIMs and employed as tools for the removal of target ions from an aqueous source phase into an aqueous receiving phase. Experiments have been conducted for i. solutions containing single cations species (to measure the transport efficiency of the incorporated ligands towards each metal ion) and ii. mixtures of metals ions (to evaluate the selectivity of the carriers towards the target ions). The UV-Vis and transport experiments were carried out with and without ionic strength adjustment to probe its effects on the complexing properties and transport efficiency of the investigated systems. Me O O O R R O Me 1 2 R CH2C(O)NHSO2Ph CH 2C(O)NHSO 2C 6H 4-4-NO 2 [1] G. Arena, A. Contino, A. Magrì, D. Sciotto and J. D. Lamb, Supramol. Chem., 1998, 10, 5- 15. [2] G. G. Talanova, H. S. Hwang, V. S. Talanov and R. A. Bartsch, Chem. Commun., 1998, 419- 420; G. G. Talanova, H. S. Hwang, V. S. Talanov and R. A. Bartsch, Chem. Commun., 1998, 1329-1330. PSB 58 Synthesis, metal ion complexation and polymric membrane ion-selective electrode studies of some novel calix[4]arene-crown macrocycles M. Shamsipur a , M. Taghdiri b , M. K. Rofouei b , S. Sahari a , K. Alizadeh a , Z. Asfari c , M. Leroy c a Department of Chemistry, Razi University, Kermanshah, Iran b Department of Chemistry, Tarbiat Moallem University, Tehran, Iran c Laboratoire de Chimie Analytique, UMR 7178 ULP/CNRS/IN 2P3 (LC4) ECPM, 25 rue Becquerel, F-67087, Strasburg Cedex, France Five novel calix[4]arene-crown macrocycles L1-L5 (Scheme 1) were successfully synthesized and fully characterized [1]. The complexation of these ligands with several alkali, alkaline earth and transition metal ions in acetonitrile solution was investigated using conductometric, spectrophotometric, 1 H-NMR and 133 Cs-NMR methods. Depending on the nature and size of metal ions used and structural properties of the calix[4]arene-crown macrocycles, different metal-to-ligand stoichiometries of 1:1, 2:1 and 3:2 were confirmed in solution. The stability constants of the resulting complexes were evaluated from computer fitting of the corresponding conductance, absorbance or chemical shift versus mole ratio data. To obtain more information about the conformational changes of the calix[4]arene-crowns upon complexation with some metal ions, the molecular structures of free ligands and their metal ion complexes were built with the Hyperchem program version 7.0 [2]. The structure of free ligands were optimized using the 6-31G* basic set at the restricted Hartree-Fock (RHF) level of theory. The optimized structures of ligands were then used to find out the initial structure of their metal ion complexes. Finally, the structures of the resulting complexes were optimized using the Lan12mb basis set at the RHF level of theory, using the Gaussian 98 program. Sample results are shown in Scheme 2. Based on the selectivity results obtained from complexation studies, some of the ligands were used as suitable ionophores for the preparation of PVC-membrane ion-selective electrodes for the corresponding metal ion-ligand systems. An interesting example is a highly selective and sensitive potentiometric sensor with a limit of detection of 1.0 10 -6 M for barium ion based on ligand L2. The details of the results obtained on the complexation and polymeric membrane ionselective electrode studies of the ligands L1-L5 will be discussed in this seminar. L1 L2 L3 L4 L5 Scheme 1. Structures of ligands L1-L5 Scheme 2. Optimized structures of free L2 and its Ba 2+ complex [1] Z. Asfari, P. Thuery, M. Nierlich, J. Vicens, Tetrahedron Lett., 1999, 40, 499-502. [2] M. Shamsipur, M. Hosseini, K. Alizadeh, M. F. Mousavi, A. Garau, V. Lippolis, A. Yari, Anal. Chem., 2005, 77, 276-283.
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nd International Symposium on Macro
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Eric Anslyn University of Texas at
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1 Map of Salice Terme 7 5 6 3 9 2 8
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Symposium Program All sessions will
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11:40 - 12:00 Oral Presentation: V.
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PSA 22 Anion Receptors Based On The
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PSA 72 Molecular Tectonics: STM Stu
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PSB 11 Dual binding properties of p
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PSB 57 Removal Of Heavy Metal Ions
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40 years of polyazamacrocycles. A p
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PL 5 Anion-Templated Assembly of In
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Exercising Demons: Synthetic Molecu
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Synthetic Strategies and Structural
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Anion binding as a conformational a
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Supramolecular control of a metal c
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OP 3 Control of molecular architect
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Catalyst discovery using dynamic co
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Cucurbit[n]uril Molecular Container
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OP 15 From non-mesomorphic nature t
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OP 19 Pyrrolic Tripodal Receptors f
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PSA 1 Efficient synthesis of pseudo
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Tetra-Cationic phthalocyanines Yasi
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PSA 9 Cell penetrating borosilica n
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PSA 13 Halide anion interactions wi
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Sensing with cavitands: Moving from
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Lead(II) complexation by calix[4]-h
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Functional [2×2] Grids Xiao-Yu Cao
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Neutral supramolecular systems inco
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PSA 33 Ratiometric Ion Sensors by R
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A photocontrollable receptor for Cu
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New emitters for mass spectrometric
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PSA 45 A fast-moving electrochemica
Page 65 and 66: Macrocyclic Porphyrin-Bidentate Che
Page 67 and 68: PSA 53 Electronic spectroscopy of e
Page 69 and 70: PSA 57 Self-assembly of calixarene/
Page 71 and 72: PSA 61 Piperazine Containing Polyam
Page 73 and 74: PSA 65 Synthesis of Self-Assembly S
Page 75 and 76: PSA 69 Assembly of Metallomacrocycl
Page 77 and 78: Supra-Biomolecular Tandem Assays -
Page 79 and 80: PSA 77 Synthesis and molecular reco
Page 81 and 82: PSA 81 Reaction of phthalic aldehyd
Page 83 and 84: Binding of perrhenate and pertechne
Page 85 and 86: PSA 89 Supramolecular assemblies of
Page 87 and 88: Polytopic Ligands for the Recovery
Page 89 and 90: PSB 1 Rosette Nanotubes as Scaffold
Page 91 and 92: PSB 5 Towards the development of ne
Page 93 and 94: PSB 9 A Quantitative [2]Rotaxane Sy
Page 95 and 96: Metal Complexes of the Polyether Io
Page 97 and 98: PSB 17 Metal controlled anion inter
Page 99 and 100: Crown Ether-tert-Ammonium Salt Comp
Page 101 and 102: PSB 25 A Minimalist Design for Self
Page 103 and 104: PSB 29 Control of Translation of th
Page 105 and 106: PSB 33 Multinuclear NMR, ESI MS and
Page 107 and 108: PSB 37 New Anthracene-based cycloph
Page 109 and 110: PSB 41 1,3,5-Tris(2-aminophenyl)ben
Page 111 and 112: Simple Isophthalamide Derivatives A
Page 113 and 114: PSB 49 On Sokolov’s approach to a
Page 115: PSB 53 New chromogenic sensors usin
Page 119 and 120: PSB 61 Molecular Recognition of Ele
Page 121 and 122: PSB 65 Switching of Self to non-Sel
Page 123 and 124: Investigation of -cyclodextrin bind
Page 125 and 126: Novel ditopic probes for different
Page 127 and 128: PSB 77 Synthesis, supramolecular ar
Page 129 and 130: PSB 81 Tripodal polyamines as anion
Page 131 and 132: PSB 85 Templated Synthesis of Large
Page 133 and 134: PSB 89 Direct C-C coupling of 1,2,4
Page 135 and 136: PSB 93 The study of cytotoxicity ef
Page 137 and 138: PSB 97 Development of innovative so
Page 139 and 140: Campbell B. PSA 39 Campbell F. PSB
Page 141 and 142: Jensen L.G. PSA 82 Jeppesen J.O. IL
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ISMSC 2007 - Università degli Studi di Pavia

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