AbstractExcitation of Ru(bipy)32+ion by visible radiation of wavelength λ = 436 nm in aqueous medium in presence of inorganic peroxides, peroxomonosulfate (PMS), peroxodisulfate (PDS), and peroxodiphosphate (PDP) was found to generate Ru(bipy)33+. The kinetics of this photochemical oxidation of Ru(bipy)32+by each peroxide was followed spectrophotometrically and found to obey a total second‐order, first‐order each in [Ru(bipy)32+] and [peroxide]. In the absence of light, thermal reaction of PMS and PDS with Ru(bipy)32+occurred but only when at 1.0 M [H+] and>10−2M [peroxide]. The reaction of PMS with the complex is found to be cyclic, ie., Ru(bipy)33+formed oxidizes PMS itself and such a reaction was not observed in the case of PDS and PDP. The effects of pH, [peroxide], and [Ru(bipy)32+] on the visible light induced oxidation of Ru(bipy)32+by these peroxides are investigated. The results are discussed with suitable reaction mech