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

Two new Schiff base complexes, [Ni2(HL)2(μ1,3-N3)]ClO4·H2O (1) and [Co(L)(N3)] (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.

► A less-studied pentadentate Schiff base was used to synthesize Ni(II) and Co(III) complexes. ► Syntheses were achieved by the reaction of the respective metal perchlorate with ligand plus azide. ► The same synthetic system yielded an azido-bridged Ni(II) and a mononuclear Co(III) complex. ► Low temperature magnetic studies establish the ferromagnetic nature of the Ni(II) complex.