Quantum-chemical calculation of chemical shifts of13C nuclei in alkanes

Abstract

1. A semiempirical method was proposed for calculating the chemical shifts of the13C carbon nuclei in saturated hydrocarbons on the basis of the correlation dependence of\(\delta _{13_C }\) on the effective charges Qieff of the atoms that surround a given13C nucleus. 2. A computer program was composed for calculating\(\delta _{13_C }\) on the basis of the proposed correlation method. 3. The chemical shifts of the13C nuclei were calculated for a number of n-alkanes ranging from propane to nonane. 4. It was shown that the values of\(\delta _{13_C }\), calculated within the framework of the self-consistent scheme of perturbation theory, are less accurate than the\(\delta _{13_C }\) obtained using the correlation method.