Bonding in clusters. Part 6. An evaluation of Stone's theory of bonding in closo-borane anions, through MNDO calculations

Abstract

MNDO calculations on closo-borane anions are used to assess the accuracy of a recently reported theory of their electronic structure and bonding. The assumptions and results of the theory are found to be fully supported, and parameters are determined that allow molecular orbital energies and composition to be calculated in a manner similar to Hückel theory. The theory is found to be equally applicable to closo-carborane molecules, and parameters are determined for these, and also accounts for the exo-BH bonding orbitals. The implications of Stone's theory for the bonding of related metal clusters are considered.