Electronic Structure and Bonding in Tricoordinate Amido Complexes of Transition Metals

A theoretical study of bonding and structure in tricoordinate amido complexes with different d n electron configurations is presented. The relative stability of the high- and low-spin states of [Co(NH 2 ) 3 ] is discussed, and the preferred orientation of the amido ligands relative to the coordination plane is analyzed for the high-spin state of the [M(NR 2 ) 3 ] compounds, where M = V(IV), Cr(III), Mn(III), Fe(III), Co(III), or Ni(II) and R = H or SiH 3 . Comparison of the computational results with experimental data provides information on the influence of electronic and steric effects. The existence of metal−ligand π bonding is discussed in the context of the electron configurations, calculated bond distances, and spin-density distributions.