Use of the 2-pyridinealdoxime/n,n′-donor ligand combination in cobalt(III) chemistry: Synthesis and characterization of two cationic mononuclear cobalt(III) complexes

Abstract

The use of 2-pyridinealdoxime (paoH)/N,N-donor ligand (L-L) blend in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)2 (L-L) ]+, where L-L = 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy). The CoCl2 /paoH/L-L (1:2:1) reaction system in MeOH gives complexes [Co III(pao)2(phen)]Cl 2H2O (1.2 H2O) and [CoIII(pao)2(bpy)]Cl 1.5MeOH (2 1.5MeOH). The structures of the complexes were determined by single-crystal X-ray crystallography. The CoIII ions are six-coordinate, surrounded by three bidentate chelating ligands, that is, two paō and one phen or bpy. The deprotonated oxygen atom of the paō ligand remains uncoordinated and participates in hydrogen bonding with the solvate molecules. IR data of the complexes are discussed in terms of the nature of bonding and the known structures. Copyright © 2010 Konstantis F. Konidaris et al.