VALENCE-BOND CONCEPTS APPLIED TO THE MOLECULAR MECHANICS DESCRIPTION OF MOLECULAR SHAPES - 3 - APPLICATIONS TO TRANSITION-METAL ALKYLS AND HYDRIDES

Recently we reported a qualitative, valence bond derived model for des cribing the shapes of transition metal complexes, with a focus on meta l hydrides and alkyls. This model, based on the concepts of hybridizat ion and resonance, rationalizes the unusual and varied shapes of hydri de and alkyl complexes with transition metals. This paper demonstrates the quantitative incorporation of these valence bond concepts into mo lecular mechanics algorithms. The resulting force field method (HV-VB) accurately describes the structures of alkyls and hydride complexes o f the transition metals. For a wide variety of crystallographically ch aracterized molecules, the HV-VB computations faithfully reproduce the observed structures.