Department of Chemistry, University College of Swansea, Singleton Park, Swansea, SA2 8PP UK
Abstract:
The rate constant for the reaction between the sulphate radical (SO4√−) and the ruthenium (II) tris-bipyridyl dication (Ru(bipy)32+) is (3.3±0.2)×109 mol−1 dm3 s−1 in 1 mol dm−3 H2SO4 and (4.9±0.5)×109 mol−1 dm3 s−1 in 0.1 mol dm−3, pH 4.7 acetate buffer. The SO4√−radical produced by the electron transfer quenching of Ru(bipy)32+* by S2O82− reacts rapidly with both acetate buffer and chloride ions. These side reactions result in a reduction in the overall quantum yield of Ru(bipy)33+ production and reduced reaction selectivity when Ru(bipy)32+* is quenched by persulphate.