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Сотрудники РЦ приняли участие в конференции VVV-2012, проводившейся в Новосибирске 15-20 июля 2012 года. Представлен доклад:
P. M. Tolstoy, B. Koeppe, J. Guo, S. A. Pylaeva, G. S. Denisov, H.-H. Limbach, «Reaction Pathways of Proton Transfer in Anionic OHO Hydrogen Bonded Complexes».
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На конференции Nuclear Magnetic Resonance in Condensed Matter 2012 (NMRCM), проходившей с 9 по 13 июля 2012 г. в Санкт-Петербурге, были представлены следующие доклады:
E. V. Kurenkova, A. V. Vyvodceva, M. G. Shelyapina, S. A. Lavrov, A. V. Ievlev, V. I.Chizhik, A. G. Aleksanyan, S. K. Dolukhanyan, N. E. Skryabina
«Proton NMR study of Ti1-xVxHy hydrides: hydrogen site occupancy and mobility»
A. V. Vyvodceva, E. V. Kurenkova, M. G. Shelyapina
«Proton spin-lattice relaxation in hydrides of Ti1-xVx alloys».
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Сотрудники РЦ приняли участие в конференции NMRCM-2012, проводившейся в Санкт-Петербурге 9-14 июля 2012 года. Представлены два доклада:
а) P. Tolstoy, B. Koeppe, S. Pylaeva, E. T. J. Nibbering, D. Sebastiani, G. Denisov, H.-H. Limbach, «Solvation of H-Bonded Complexes by Polar Aprotic Solvents: Coupling of the Proton Position to the Solvent Configuration».
б) S. Pylaeva, P. Tolstoy, B. Koeppe, C. Allolio, D. Sebastiani, G. Denisov, «Fluctuations of H-bond geometry due to the solvent-solute interactions studied by means of computer simulations». Доклад получил премию за лучший постер.
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J. Guo, P. M. Tolstoy, B. Koeppe, N. S. Golubev, G. S. Denisov, S. N. Smirnov, H.-H. Limbach
«Hydrogen Bond Geometries and Proton Tautomerism of Homo-Conjugated Anions of Carboxylic Acids Studied via H/D Isotope Effects on 13C NMR Chemical Shifts»
J. Phys. Chem. A 2012, ASAP.
DOI: 10.1021/jp304943h.
Abstract:
Ten formally symmetric anionic OHO hydrogen bonded complexes, modeling Asp/Glu amino acid side chain interactions in nonaqueous environment (CDF3/CDF2Cl solution, 200–110 K) have been studied by 1H, 2H, and 13C NMR spectroscopy, i.e. intermolecularly H-bonded homoconjugated anions of acetic, chloroacetic, dichloroacetic, trifluoroacetic, trimethylacetic, and isobutyric acids, and intramolecularly H-bonded hydrogen succinate, hydrogen rac-dimethylsuccinate, hydrogen maleate, and hydrogen phthalate. In particular, primary H/D isotope effects on the hydrogen bond proton signals as well as secondary H/D isotope effects on the 13C signals of the carboxylic groups are reported and analyzed. We demonstrate that in most of the studied systems there is a degenerate proton tautomerism between O-H···O– and O–···H–O structures which is fast in the NMR time scale. The stronger is the proton donating ability of the acid, the shorter and more symmetric are the H-bonds in each tautomer of the homoconjugate. For the maleate and phthalate anions exhibiting intramolecular hydrogen bonds, evidence for symmetric single well potentials is obtained. We propose a correlation between H/D isotope effects on carboxylic carbon chemical shifts and the proton transfer coordinate, q1 =1/2(rOH – rHO), which allows us to estimate the desired OHO hydrogen bond geometries from the observed 13C NMR parameters, taking into account the degenerate proton tautomerism.
