Crystal structures and superoxide dismutase mimetic activity of [CuL(2)(Him)(2)]center dot MeOH and [CuL(2)(mim)(2)]center dot H2O [HL=4-amino-N-(thiazol-2-yl)benzenesulfonamide, Him equals imidazole, mim equals N-methylimidazole]

The complexes [CuL(2)(Him)(2)]. MeOH 1 and [CuL(2)(mim)(2)]. H2O 2 [HL = 4-amino-N-(thiazol-2-yl)-benzenesulfonamide, Him = imidazole, mim = N-methylimidazole] have been prepared and their crystal structures determined. In 1 the metal centre has a very irregular stereochemistry, being co-ordinated by six nitrogen atoms, two of them from the imidazole ligands and the other four from three sulfonamides, one belonging to an adjacent asymmetric unit. The crystal packing shows stacking interactions between the imidazole and phenyl rings of the sulfonamide. In 2 the co-ordination polyhedron is intermediate between square pyramidal and trigonal bipyramidal. Spectroscopic and electrochemical data are in accord with the crystal structures. The in vitro O-2(-) scavenger activity of the complexes shows that they exhibit high superoxide-dismutase mimetic activity.