The N-acylhydrazine grouping as a ligand. I. Coordination compounds of Keto- and Enol-N-acylhydrazines with cobalt(II), nickel(II), and copper(II)

Abstract

Ligands containing the N-acylhydrazine grouping, RCONHKH₂, act as bidentate chelating agents with transition metal ions. Cationic complexes of coba1t(11), nickel(11), and copper(11) containing the ligands coordinated in the keto form were isolated, but the ligands also reacted in the enol form producing neutral complexes with cobalt(111) and copper(11). Complex formation in the enol form was facilitated by condensation of the ligands with acetone to produce the N'-iso-propylidene derivatives, from which keto complexes were also isolated. Under certain conditions N-acylhydrazines can act as reducing agents, leading to the formation of complexes containing copper in both oxidation states (I) and (11). Using N-benzoylhydrazine, this reaction can be utilized as a benzoylating medium for amines.