Search. Read. Cite.

Easy to search. Easy to read. Easy to cite with credible sources.

Journal of Coordination Chemistry

Year: 2009  |  Volume: 62  |  Issue: 23  |  Page No.: 3864 - 3874

Synthesis and spectral studies of nickel(II) complexes derived from disalicylaldehyde oxaloyldihydrazone

R. A. Lal, S. Choudhury, A. Ahmed, M. Chakraborty, R. Borthakur and A. Kumar

Abstract

The mononuclear nickel(II) complex [Ni(H2slox)(H2O)3] (1) and polymeric dinuclear complexes [Ni2(slox)(A4)] {A = H2O (2), py (3), 2-pic (4), 3-pic (5) and 4-pic (6)} and the discrete binuclear complexes [Ni2(slox)(NN)3] {NN = bpy (7) and phen (8)} have been synthesized from disalicylaldehyde oxaloyldihydrazone (H4slox) in methanol. All of the complexes are nonelectrolytes. Complexes 1, 7, and 8 are paramagnetic while binuclear 2-6 possess anomalously low μeff value, indicating considerable metal-metal interaction. Discrete binuclear 7 and 8 have no interaction between the two nickel(II) ions. The anomalously low magnetic moment values in 2-6 are explained as metal-metal interaction via phenoxide bridge. Such metal-metal interactions are less in 7 and 8 due to coordination of bipyridine and phenanthroline molecules which do not allow phenoxide bridging. The dihydrazone coordinates to the metal center as a dibasic tridentate ligand in keto-enol form in staggered configuration in 1, while in the remaining complexes the dihydrazone is tetrabasic hexadentate in enol form in anticis configuration. The metal center has a tetragonally distorted octahedral stereochemistry.

View Fulltext