MOLECULAR MODELING OF VANADIUM-OXO COMPLEXES - A COMPARISON OF QUANTUM AND CLASSICAL METHODS

A force field for vanadium-oxos was developed and tested with a variet y of complexes with coordination numbers of 5 or 6 and formal oxidatio ns states of +4 or +5 on the metal. Similarly, a semiempirical quantum mechanical method for transition metals was extended to vanadium. In this research soft and hard ligands were studied, as were ligands coor dinated through single, multiple, and dative bonds. Despite the divers ity of vanadium coordination chemistry, generally good modeling is ach ieved in a fraction of the time with less computational resources usin g molecular mechanics and semiempirical quantum mechanics. The L4V4+O and L5V5+O groups were emphasized given their prevalence and importanc e. In general, the predictive ability was superior for the former stru ctural motif. The combination of molecular mechanics and semiempirical quantum calculations provide an effective and efficient tool for anal ysis of the steric and electronic energy differences between isomers.