Szilágyi I, Labádi I, Hernadi K, Pálinkó I, Nagy N V, Korecz L, Rockenbauer A, Kele Z, Kiss T
Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged H-6720, Hungary.
J Inorg Biochem. 2005 Aug;99(8):1619-29. doi: 10.1016/j.jinorgbio.2005.05.001.
The solution equilibrium and the binding mode of the species in the five-component system containing two metal ions (copper(II) and zinc(II)) and three ligands (A=diethylenetriamine, B=imidazole, C=tris(2-aminoethyl)amine) were investigated by pH-potentiometric titration, UV-visible spectrophotometry and EPR (electron paramagnetic resonance) spectroscopic titration in aqueous solution in the 2-11 pH range. An imidazolate-bridged heterobinuclear complex (ACuBH(-1)ZnC) was found to evolve above pH=7 and was stable between pH 7 and 11. The existence of the ACuBH(-1)ZnC complex (by determination of its molecular weight) was proved by mass spectrometry (ESI-MS (electrospray ionization mass spectrometry) and MALDI (matrix-assisted laser desorption/ionization) techniques). The electrochemical behaviour and the superoxide dismutase activity of this complex were also tested by cyclic voltammetry and the Riboflavin/NBT (nitro blue tetrazolium) assay, respectively.
