Synthesis and crystal structures of the Zn(II) and Co(II) complexes containing the reduced derivative nitronyl nitroxide

Two complexes of formulas [Zn(Hfac)2(IM-IMH-Bph)] (I) and [Co(Hfac)3](IM-Bph) (II), where IM-Bph = 2,2′-bis(1′-oxyl-4′,4′,5′,5′-tetramethylimidazoline-2′-yl)-bis(2-formylphenyl) ether; Hfac = hexafluoroacetylacetonate, have been synthesized and characterized by single-crystal X-ray diffraction. The X-ray analysis demonstrates that both I and II are mononuclear complexes. In I, each zinc ion is five-coordinated with four oxygen atoms from two Hfac ligands and one oxygen atom from nitroxide. Complex II contains one Co(III) atom with six oxygen atoms from three Hfac ligands and uncoordinated IM-Bph diradical, in which the Co2+ ion and NIT-Bph biradical can undergo the redox reaction.