Synthesis, characterization and structural determination of some nickel(II) complexes containing imido Schiff bases and substituted phosphine ligands

Some new tridentate ONN Schiff base complexes of [NiL(PR3)] (where L = Salicylidene2-amino4-nitrobenzene (L-1), 5-BrSalicylidene2-amino4-nitrobenzene (L-2), 5-NO(2)Salicylidene2-amino4-nitrobenzene (L-3), 5-MeOSalicylidene2-amino4-nitrobenzene (L-4) and 3-MeOSalicylidene2-amino4-nitrobenzene (L-5), R = Bu and Ph (with L-1)) were synthesised and characterized by IR, UV-Vis, H-1 NMR spectroscopy and elemental analysis. The geometry of [NiL1(PPh3)] was determined by X-ray crystallography. It indicated that the complex had a planar structure and four coordinates in the solid state. The thermogravimetry (TG) and differential thermoanalysis (DTA) of the synthesized complexes were carried out in the range of 20-600 degrees C, leading to the decomposition of L-1-L-3 type in three stages and of L-4-L-5 and [NiL1(PPh3)] type in four stages. Thermal decomposition of the complexes was closely the dependent upon the nature of the Schiff base ligands and proceeded via the first order kinetics. (C) 2013 Published by Elsevier B.V.