X-ray absorption spectroscopy study of the local atomic environment of Cu, Ni, AND Co in metal complexes of aminomethylene derivatives of pyrazol-5-one

Abstract

The local atomic environment of Cu, Ni and Co ions in a series of new metal complexes with various aminomethylene derivatives of pyrazol-5-one was studied by X-ray absorption spectroscopy. The EXAFS and XANES analysis revealed that in the nickel and cobalt complexes which ligands have azo group N=N-Ph(CH3-n) in the ortho position of amine fragment, the octahedral coordination occurs due to additional bonds of nitrogen in the azo group with the metal ion. In complexes of these metals having azo group N=N-Ph in the para position of amine fragment of the ligand, coordination is close to tetrahedral, whereas for copper complexes the tetrahedral environment of metal ion is observed irrespective of the ligand type.