METAL-ASSISTED PYRAMIDAL INVERSION IN METAL PHOSPHIDO COMPLEXES

The first systematic theoretical treatment of metal-assisted pyramidal inversion in metal-phosphido complexes is presented. We find that two effects dominate inversion barrier trends. The first effect, which is most important in early transition metal complexes, involves stabiliz ation of the planar form through ligand-to-metal pi bonding. The secon d effect, seen in middle and late transition metal systems, can be des cribed as inductive destabilization of the pyramidal ground state. Bot h of these effects lower the inversion barriers relative to those foun d in PR3 systems (R = alkyl group).