1,2,3-Triketohydrindene hydrate (NHy) shows well-defined redox electrochemistry in the formation of monoanionic radical (NHy(center dot-)) and dianion (NHy(2-)) in nitrogen saturated aprotic solvents such as acetonitrile and dimethylsulfoxide. Cyclic voltammetry reveals that in an oxygen-saturated solution of DMSO, the oxidation peak of superoxide anion (O-2(center dot-)) at -0.7 V versus Ag/AgCl wire electrode, decreases systematically with increasing NHy concentration. The similar behaviour is observed in the rotating disk voltammetry. On Pt disk, oxygen is reduced to O-2(center dot-) at a constant potential of -0.8 V and at Pt ring, O-2(center dot-) is oxidised to oxygen and the corresponding limiting current plateau in the ring voltammogram is decreased linearly as [NHy] is increased. In aqueous solutions, NHy is found to exhibit completely different redox chemistry due to its structural changes and hence showed no favourable redox potentials for efficient quenching of O-2(center dot-). (c) 2005 Elsevier Ltd. All rights reserved.