The Synthesis and Characterization of the First Tris-Chelate Complexes of Vanadium(Iii), Chromium(Iii) and Manganese(Iii) Containing Deprotonated 4-Phenacetylidene-2,2,5,5-Tetramethylimidazolidin-1-Oxyl Nitroxyl Free Radical Ligand

E. M. R. Kiremire¹, G. Kumar², H. Muwowo³, K. Chibale⁴

¹Department of Chemistry, University of Zambia, Lusaka (Zambia) ²Department of Chemistry, University of Cape Town, Rondebosch 7701 (South Africa) ³Department of Chemistry, University of Witwatersrand, WITS 2050, Johannesburg (South Africa) ⁴Department of Chemistry, University of Nairobi, Nairobi (Kenya)

The first spin-labelled tris-chelate complexes of the general formula ML3, M=V(III), Cr(III), Mn(III) and L is the deprotonated 4-phenacetylidene-2,2,5,5-tetramethyl-imidazolidin-1-oxyl nitroxyl free radical ligand have been synthesized and characterised by elemental analysis, mass spectroscopy, FT IR, magnetic susceptibility measurements and electron spin resonance technique. The evidence indicates that the nitroxyl radical acts as a bidentate ligand.

Tris-chelate complexes; Nitroxyl radical and Bidentate ligand