Photoredox chemistry of mercury ions in aqueous ethanol solutions

Mercury(II) is reduced to mercury(I) upon irradiation (lambda(ir) = 254 nm) in air-saturated aqueous solution containing ethanol. The quantum yield of this reaction linearly depends on the alcohol concentration. The product o f this process is Hg-2(2+), which is photoactive too. Photostationary state with Hg(I)/Hg(II) ratio depending on the alcohol concentration can be reac hed in this system. Thus, photoassisted catalytic oxidation of alcohol to a ldehyde takes place in such a state. Flash photolysis experiments confirmed that the reactions of Hg+ and Hg-2(+) formed in the primary steps of the p hotoinduced process are strongly affected by mercury(II), oxygen, and alcoh ol. (C) 1999 Elsevier Science S.A. All rights reserved.