Département de chimie moléculaire

σ-Bond metathesis reactions of water and methanol with palladium hydride and Me complexes to yield hydrogen and methane, resp., have been studied using ab-initio MO methods at the second-order Moller-Plesset (MP2) perturbation level. The calcns. show that such reactions are feasible and that they can in some instances be competitive with an oxidative addn./reductive elimination sequence. A key factor is the presence of an addnl. lone pair not engaged in the initial bonding of the metal atom with the reacting water or alc. Another important controlling factor is the resp. charges of the reacting entities. The importance of the choice and of the disposition of the ancillary ligands in the coordination sphere is emphasized.