A Molecular Mechanics Force Field for Alkylcobaloximes, a Model of Vitamin B12 Coenzyme - Implications of Steric and Electronic Factors in the Co-C Bond Cleavage

Synthesis of new palladium(II) (1), nickel(II) (2a and 2b), and cobalt(II) (3) complexes bearing the unsymmetrical, bidentate nitrogen ligand 2,6-bis(1-methylethyl)-N-(2-pyridinylmethylene)phenylamine (L) is described. The solid-state structures of 1, 2a, and 2b have been determined by single-crystal X-ray diffraction. The PdII compound exists in the monomeric form whereas the nickel complexes were observed as centrosymmetric dimers with slightly distorted square-pyramidal coordination sphere around each nickel center.