Synthesis and characterisation of copper(II), nickel(II) and cobalt (II) complexes of 3-(2-hydroxypheny)-5- (4-X-phenyl)pyrazolines

722-723Complexes of 3-(2-hydroxyphenyl)-5-(4-X-phenyl)pyrazolines (X = H, Me, MeO) with copper(II), nickel(II) and Cobalt(II) have been synthesized and characterized . The IR spectra indicate coordination through phenolic oxygen and azomethine nitrogen of pyrazoline ring. The copper(II), nickel(II) and cobalt(II) complexes have magnetic moments and ligand field bands characteristic of low- spin square- planar configuration. The strong field nature of the ligand, in contrast to the weak field nature of 3-(1- hydroxy2- naphthyl)-5-(4-X-phenyl)pyrazolines, has been ascribed to dπ-pπ back bonding