Premium
Ab initio quantum‐mechanical calculations of the variation of the magnetic shielding constant of hydrogen and carbon 13 nuclei of the dimethylphosphate anion as a function of molecular conformation: A model study for nucleic acid constituents
Author(s) -
Prado F. Ribas,
GiessnerPrettre C.,
Pullman B.
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560160735
Subject(s) - chemistry , molecule , electromagnetic shielding , hydrogen bond , ab initio , ion , ab initio quantum chemistry methods , computational chemistry , crystallography , nuclear magnetic resonance , organic chemistry , materials science , composite material , physics
The magnetic shielding constants of. carbon 13 and hydrogen nuclei of the dimethylphosphate anion are calculated for the gauche‐gauche and gauche‐trans conformations of the molecule as a function of the rotational angles about the PO and CO bonds. The results obtained show that for the protons the value of the rotational angle about the CO bond is more important than that about the PO bond. For carbon 13 of the two methyl groups of the molecule the gt conformation corresponds to magnetic shielding constants which are shifted downfield with respect to their values for the gg conformation. These results are discussed in relation to the role of the variations of some of the conformational parameters of the ribose phosphate backbone of polynucleotides in the nuclear magnetic resonance spectra of this type of molecule.