Synthesis and X-ray structures of new mononuclear and dinuclear diimine complexes of late transition metals

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 so lid-state structures of 1, 2a, and 2b have been determined by single-crysta l X-ray diffraction. The Pd-II compound exists in the monomeric form wherea s the nickel complexes were observed as centrosymmetric dimers with slightl y distorted square-pyramidal coordination sphere around each nickel center.