Co(II), Cu(II) and Zn(II) dinuclear complexes of a polypodal ligand containing phenolate and pyridyl donor groups

Acetate and perchlorate dinuclear metal complexes of Co(II), Cu(II) and Zn(II) with the cresolate polypodal ligand having mixed phenolate and pyridyl pendant functionalities, H3L, have been synthesized. The complexes were characterized by microanalysis, LSI mass spectrometry, IR, UV-Vis spectroscopy, magnetic studies and conductivity measurements. Crystal structures of H3L, [Cu-2(HL)(OAc)(H2O)(2)](OAc)center dot 1.5H(2)O and [Zn2L(CH3OH)(3)](ClO4)CH3OH center dot 2H(2)O complexes, have been also determined. The X-ray studies show the presence of dinuclear complexes with the metal ions joined by the bridging cresolate group and coordinated to the tertiary amine nitrogen and their corresponding attached pyridyl and phenol/phenolate pendant groups. The coordination environment for the metal ions is completed by acetate, water or solvent molecules to generate mixed distorted coordination geometries; square plane/square pyramidal for Cu(II) and octahedral/trigonal bipyramidal for Zn(II) complexes. Different intramolecular interactions through hydrogen bonds are also observed in both complexes. (C) 2010 Elsevier Ltd. All rights reserved.