Calcul des déplacements chimiques par la méthode des perturbations finies au niveau INDO avec GIAO et approximation de London. I. 13C et 1H

Abstract

A formalism for the calculation of σ in the finite perturbation method is developed by keeping hermitian the first order perturbed matrix in B. The σ formalism is separated into mono, di, and triatomic terms, and the importance of the electron densities of neighboring and remote bonds is shown. 13C chemical shifts depend only slightly on the remote bonds in contrast to those for 1H. A calculation of the screening constant for a series of 16 sp and sp2 carbons gives an average precision of 5 ppm for the 13C nuclei. [Journal Translation]