Two New Quadridentate Schiff Base Complexes of Nickel(II) and Cobalt(III): Synthesis, Structure and Spectral Characterisation

Two novel quadridentate Schiff base complexes, [NiIILH](ClO4)2・H2O (1) and [CoIIIL]- (ClO4)2・H2O (2) [LH, a Schiff base ligand: Ph(OH)C(Me)=NCH2CH2N(CH2CH2NH2)2] have been synthesised and characterised by elemental analyses, spectroscopic and electrochemical studies. The structures of both have been unequivocally established from single crystal X-ray diffraction studies. 1 and 2 crystallise in the monoclinic space group P21/n having cell parameters a = 8.536(1), b = 13.832(4), c = 18.194(2) Å , β = 100.00(10)°, Z = 4 for 1, and a = 10.819(5), b = 14.301(2), c=14.224(1) Å , β =97.04(2)°, Z =4 for 2. The complexes expose a square planar geometry around the metal centers chelated with three different types of nitrogen donor centers of the ligand.