RETRACTED: A theoretical study of the bonding structure of carbonyl sulfide, OCS (Retracted Article)

Abstract

A question has been raised on the possible difference between the two electric polarizability tensor elements perpendicular to the molecular axis of OCS molecule, possibly, due to the significant difference between O=C and C=S pi-bonds, predicted by both the VB and localized MO theories. In other words, the VB and localized MO pictures for this molecule has been criticized. This question has been addressed by examining electronic characteristics as well as the degeneracy of the bending vibrational modes of this molecule at different ab initio RHF, CIS, MP4, and DFT-B3LYP levels of theory. The results showed that no isolated molecular orbitals corresponding to the individual O=C and C=S pi-bonds exist in this molecule. It is also found that electronic characteristics of this molecule have a cylindrical symmetry with respect to the molecular axis, as is expected from the symmetry of its total Hamiltonian reflected in the HF, post-HF and DFT-KS orbitals. Deficiency of classical VB theory is suggested to be cured by introducing a new type of resonance in which different resonance structures differ only in the orientation of the set of atomic valence orbitals, which are correlated by a C-n operation, without any differences in the bond orders and cross-populations between the participating atoms. (C) 2004 Elsevier B.V. All rights reserved.