Premium
Experimental and computational studies of n J ( 77 Se, 1 H) selenium–proton couplings in selenoglycosides
Author(s) -
Kövér Katalin E.,
Kumar Ambati Ashok,
Rusakov Yury Yu.,
Krivdin Leonid B.,
Illyés TündeZita,
Szilágyi László
Publication year - 2011
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2731
Subject(s) - chemistry , geminal , proton , vicinal , coupling constant , computational chemistry , molecular geometry , bond length , dihedral angle , crystallography , stereochemistry , molecule , hydrogen bond , physics , nuclear physics , quantum mechanics , crystal structure , organic chemistry
Selenoglycosides are important starting materials in synthetic carbohydrate chemistry and play a role in biological interactions as well. Both aspects are influenced by the conformation around the glycosidic bond. Here, we present a combined experimental and computational approach to measure and evaluate n J ( 77 Se, 1 H) coupling constants for their use in conformational analysis. The measurements were carried out using a modified CPMG‐HSQMBC pulse scheme which yields pure absorption antiphase multiplets to allow accurate determination of the n J XH values regardless of the size of the proton‐proton couplings. Theoretical calculations were performed at the Second‐Order Polarization Propagator Approach (SOPPA) level. Population‐averaged values calculated for geminal and vicinal couplings are in a good agreement with experiment indicating an adequate theoretical level of the calculations. Experimental observations and computations alike have indicated that two ‐bond 77 Se‐ 1 H couplings, 2 J ( 77 Se, 1 H), in a H1‐C1‐Se‐X moiety are very sensitive to the torsion angle around the C1‐Se‐bond and will, therefore, be useful for conformational studies. Copyright © 2011 John Wiley & Sons, Ltd.