Effect of tunable redox behavior of bis chelate substituted 1,10-phenantroline Cu(II) complexes on its reaction with superoxide anion in DMSO. Toward a simple criterion to identify a SOD-like mechanism.

In this work we report a series of Cu(II) complexes [Cu(N-N)(X)], (N-N=substituted 1,10-phenanthroline derivatives and X=Cl or NO), with tunable E for electrochemical reduction [Cu(N-N)(X)]+1e⇌[Cu(N-N)]+X. The disproportion of O was explored in presence of the electro-generated species [Cu(N-N)] using cyclic voltammetry in a non-aqueous media, arising a new simple method to propose a SOD-like mechanism, which can be used as a quick guide test for a compound, before being proven in biological assays. It was found that complexes with high negative half wave potential values (E) for Cu(II)/Cu(I) couple shown a current increment for oxygen reduction, related to the capability of the disproportion of this reactive oxygen species.