Synthesis, crystal structure and magnetic properties of nickel(II) and cobalt(III) complexes of a pentadentate Schiff base

Two new Schiff base complexes, [Ni-2(HL)(2)(mu(1,3)-N-3)]ClO4 center dot H2O (1) and [Co(L)(N-3)] (2) where L = 2,2'-{(methylimino)bis[propane-3,1-diylnitrilomethylylidene]}diphenolate ion, have been synthesized by the reaction of equimolar amounts of nickel(II) or cobalt(II) perchlorate with the pentadentate Schiff base ligand (H2L) in presence of azide ion. The complexes have been characterized by microanalytical, spectroscopic, single crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1 is an end-to-end azido-bridged binuclear complex in which each nickel(II) adopts irregular octahedral geometry. In contrast, 2 is a mononuclear octahedral cobalt(III) complex containing the azide ion in one of its apical positions. Low temperature magnetic measurements on 1 indicate noticeable intradimer ferromagnetic interactions. (C) 2012 Elsevier B.V. All rights reserved.