Localized molecular orbital calculations of vibrational circular dichroism. II. CNDO formulation and results for the hydrogen stretching vibrations of (+)-(3R)-methylcyclohexanone

Abstract

The results of localized molecular orbital (LMO) calculations of vibrational circular dichroism (VCD) for the 12 carbon–hydrogen stretching vibrations in (+)-(3R)-methylcyclohexanone are reported. The VCD is evaluated from the motion of the nuclei and the centroids of LMO’s which are obtained by localization of canonical CNDO molecular orbitals. The detailed expressions used in our CNDO–LMO–VCD procedure are given and the approximation of retaining only the one-center integrals is discussed. Comparison of the CNDO–LMO–VCD calculations to experiment shows good agreement, thus indicating a potential utility of the LMO–VCD calculational method. The results are analyzed in terms of nuclear and orbital vibrational motion and figures depicting these displacements are provided for each of the 12 normal modes.