SEMIEMPIRICAL MO CALCULATIONS OF THE ELECTRONIC SPECTRA OF NORMAL- AND BRANCHED CHAIN PARAFFINS

Abstract

CNDO, INDO and RCNDO (CNDO) including higher (Rydberg) atomic orbitals in the basis calculations completed by first order configuration interaction were performed on straight chain and branched chain paraffins. The results interpret reasonably the main characteristics of the observed electronic spectra. The importance of outer atomic orbitals is stressed and it is found that the first singlet-singlet transition of highly branched paraffins leads to an excited state with considerable Rydberg character.