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The Center started cooperation with the working group of Prof. Alexander Filarowski from the Department of Chemistry of Wroclaw University, Poland in the study of the structure and dynamics of Schiff bases and hindered rotation of the amide group in a number of organic compounds.
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Our contribution to the Central European School on Physical Organic Chemistry, 27-31 of May 2013, Poland
- Lecture by P.M. Tolstoy «NMR Study of Hydrogen Bond Cooperativity in Model Systems and in Vitamin B6-dependent Enzymes».
- Oral and poster presentation by S.A. Pylaeva «Molecular dynamics study of OHO– and OHN hydrogen bond geometry distribution due to polar solvent fluctuations».
- Oral and poster presentation by RC user E.Yu. Tupikina «CH-acids as proton donors for hydrogen bonds: structure and properties of 1,1-dinitroethane».
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Borissova, A. O.; Lyssenko, K. A.; Gurinov, A. A.; Shenderovich, I. G.
«Energy Analysis of Competing Non-Covalent Interaction in 1:1 and 1:2 Adducts of Collidine with Benzoic Acids by Means of X-Ray Diffraction»
Z. Phys. Chem. 2013, 227 (6-7), 775-790.
Abstract
The hydrogen bond pattern and the types of non-covalent interactions in the crystals of the 1:1 and 1:2 adducts of 2,4,6-trimethylpyridine and benzoic acids are studied using high-resolution X-ray diffraction. The geometries of the hydrogen bonds are estimated using a combined XRD/DFT approach that provides the geometrical parameters within the margin of error of neutron diffraction studies. The energies of the non-covalent interactions are estimated on the base of the experimental electron density distribution function. It is shown that the structures of the adducts are governed by the NOH and OHO hydrogen bonds. In turn, C-H…O contacts and stacking interactions define the packing of the adducts in the crystal. On the other hand, it is important to note that the latter interactions affect the competition of the former hydrogen bonds in some 1:2 adducts.
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Today Ryōji Noyori, the Nobel Prize winner in Chemistry in 2001, visited our Center. The day before he became Honorary Doctor at St. Petersburg State University.
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Y. Rozhkova, A. A. Gurinov, P. M. Tolstoy, G. S. Denisov, I. G. Shenderovich und V. I. Korotkov
«Acridine – a Promising Fluorescence Probe of Non-Covalent Molecular Interactions»
Zeitschrift für Physikalische Chemie, 2013, accepted
Abstract
Fluorescence and absorption spectral parameters of acridine have been studied in solution at room temperature in the presence of different proton donors aiming to inspect whether or not acridine can be used as a spectroscopic probe suitable to measure the geometry of hydrogen bonds under different conditions. It has been shown that the most appropriate spectral parameter is the position of fluorescence maximum that changes heavily upon a contraction of the N…H distance. Presumably, also the intensity of the maximum strongly depends on the hydrogen bond geometry. These two parameters can be used to establish two independent, mutually complementary correlations connecting the spectral manifestations and the geometry of hydrogen bond.
