Interatomic exchange and π-bonding involving outer d-orbitals

Abstract

A valence bond treatment has been applied to a simple diatomic model involving a π-bond between a 3d_π-sulphur orbital and a 2p_π-fluorine orbital. The effects due to non-orthogonality of orbitals on different centres have been taken into account and discussed. The results indicate that only exchange terms arising from 2π and 2π fluorine orbitals are significant. The exchange terms act as an attractive potential on the 3d π orbital whose size becomes useful for bonding. A simple formula is derived which approximates the exchange effects.