4th EucheMs chemistry congress

Poster Session 2
s1142
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - Analytical Chemistry
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inveStiGAtion of SodiuM Borohydride
eLeCtrooxidAtion MeChAniSM on SiLver
eLeCtrode in BASiC MediuM
A. orBAy 1 , G. yiLdiz 1
1 Istanbul Technical University, Chemistry, Istanbul, Turkey
As fossil fuel sources come to an end and problems due to
pollution rises, fuel cells with environment friendly reagents (like
hydrogen) become more important. Hydrogen is one of the
preferred energy sources, which can be hard to store due to limited
area capacity and exploding hazards. At this point a suitable
energy carrier compound, sodium borohydride (NaBH ), steps
4
in and conducts in-situ hydrogen generation through
hydrolysis reaction within its superior characteristics such as
non-flammability, stability and recyclability.
In this study, the electrochemical oxidation mechanism of
NaBH on silver electrode in sodium hydroxide support electrolyte
4
was investigated. The effect of sodium hydroxide concentration
and optimum conditions to obtain maximum oxidation in presence
of oxidative reagent like potassium permanganate were also
investigated.
references:
1. Santos D. M. F., Sequetra C. A. C., Renewable and
Sustainable Energy Reviews, 2011, 15, 3980-4001
2. Santos D. M. F., Sequeira C. A. C.,
Int. Journal of Hydrogen Energy, 2010, 35, 9851-9861
3. Sanli E., Uysal B. Z., Aksu M. L.,
Int. Journal of Hydrogen Energy, 2008, 33, 2097-2104
4 th EucheMs chemistry congress
P - 0 5 6 1
exPeriMentAL And CoMPutAtionAL StudieS
on the therMAL deCoMPoSition of
nitroAzidoBenzeneS
S. Öz 1 , e. ÖzKArAMete 2 , e. K. inAL 2 , i. SvoBodA 3 ,
o. AtAKoL 2 , M. A. AKAy 2
1 Ahi Evran University, Chemistry, Kirsehir, Turkey
2 Ankara University, Chemistry, Ankara, Turkey
3 TU-Darmstadt, Strukturforschung FB Materialwissenschaft,
Darmstadt, Germany
In this combined experimental and theoretical study
the thermal decomposition of 2-nitroazidobenzene (i),
2,4-dinitroazidobenzene (ii) and 2,4,6-trinitroazidobenzene (iii)
to yield benzofuroxan (iv), 4-nitrobenzofuroxan (v) and
4,6-dinitrobenzofuroxan (vi) were investigated by thermoanalytical
(TG, DSC) and computational methods. Interestingly, furoxan
formation was not observed for 4-nitroazidobenzene (vii) under
heating due to the para position of the nitro group in the benzene
ring. All compounds were characterized by elemental analysis,
vibrational (IR) spectroscopy and mass spectrometry. The crystal
structure of compound iii was determined by single crystal
X-ray diffraction [1a, b] . All calculations were carried out using the
Gaussian G09W (revision B.01 [2a] . DFT-based structure
optimizations and frequency analyses were performed at the
B3LYP/cc-pVDZ level of theory [2b] . The structural parameters of
the fully optimized compound iii was in good agreement with
the single-crystal X-ray data. The enthalpies of formation for
compounds i, ii, iii, iv, v and vi were calculated using the
complete basis set (CBS-4M) method of Petersson and coworkers
in order to obtain accurate energy values [2c] . The enthalpies of
decomposition for compounds i, iiand iii were obtained from
calculated enthalpies of formation according to Hess Law and
were compared with the experimental values which were available
from DSC analysis and were also found to be in very good
agreement.
references:
1. a) Oxford Diffraction (2002) CCD and CrysAlis RED.
Version 1. 170. 14. Oxford Diffraction, Oxfordshire,
England.
b) Sheldrick GM SHELXS97 and SHEXL97 Program for
Crystal Structure Solution and Refinement (1997)
University of Gottingen, Germany.
2. a) Gaussian 09 Software, Revision B01.2009
b) A. D. Becke, J. Chem. Phys., 88, 1053-1062, 1988
c) Jr. A. J. Montgomery, M. J. Frisch, J. W. Ochterski,
G. A. Petersson, J. Chem. Phys. 112, 6532-6553, 2000
Keywords: Thermal Decomposition; CBS-4M;
Nitroazidobenzene; IR; TG;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc