Light induced electron transfer reactions:: kinetics and mechanism of oxidation of hexacyanoferrate(II) by peroxodisulphate induced by irradiation of visible light in presence of iris(2,2′-bipyridine)ruthenium(II) ion photocatalyst in aqueous solutions

The oxidation reaction of hexacyanoferrate(II) by peroxodisulphate, (S2O82-) is accelerated by irradiation with visible light in aqueous acid solutions containing tris(2,2'-bipyridine)ruthenium(II) ion (Ru(bipy)(3)(2+)), the latter acts as a photocatalyst. The mechanism. of the reaction consists of a chain reaction initiated by the quenching reaction of the photo excited ruthenium(II) complex ion (Ru-circle times(bipy)(3)(2+)), with S2O82-. The rate law is expressed by the equation [GRAPHICS] k(q) is the bimolecular quenching rate constant and has been determined kinetically. Other terms have their usual meaning.