Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5418427 | Journal of Molecular Structure: THEOCHEM | 2006 | 5 Pages |
Abstract
With a DFT approach [B3LYP/6-31G(d,p)] the geometry of the ribonucleoside cytidine was optimized and NMR parameters (proton chemical shifts and J couplings) were calculated. Calculations of proton chemical shifts with varied base orientations of a North sugar conformer revealed a through-space effect between the OH2â² proton and the carbonyl oxygen of the base. The 3JH1â²C6 couplings were found to be similar for trans and gauche orientation of proton and carbon. This was rationalized by a NBO analysis of interaction energies between donor and acceptor natural bond orbitals. The different 3JH1â²C6 coupling constants upon rotation of the base could be correlated to the charge delocalization along the coupling pathway which was independent of the ribose conformation. The 1JH6C6 and 1JH1â²C1â² coupling constants seem to be less dominated by the hybridization of the corresponding carbon atoms.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
J.T. Fischer, S.G. Wehner, U.M. Reinscheid,