A proposal for the mechanism of the photooxidation of kinetically labile transition metal complexes. Interpretation of photoprocesses of FeSO4, FeClO4, FeCl2 in aqueous acidic solutions.
L. Vincze et al., A proposal for the mechanism of the photooxidation of kinetically labile transition metal complexes. Interpretation of photoprocesses of FeSO4, FeClO4, FeCl2 in aqueous acidic solutions., MAGY KEM FO, 106(2), 2000, pp. 85-92
A comprehensive mechanism is proposed for the photolysis of transition meta
l complexes in equilibrium solutions. This involves the photooxidation, a p
ossibility of energy transfer, and several secondary thermal reactions, e.g
. forward and back reactions with photochemically formed H-. radicals. The
scheme includes the individual quantum yield (IQY) of each species. The pho
tooxidation of FeSO4, FeClO4, FeCl2 in aqueous acidic solutions was studied
by continuous irradiation. The IQYs of Fe2+ (0.2), FeSO4 (0.3), FeHSO4+ (0
.67), FeClO4+ (0.06-0.2), FeCl+ (0.8), FeCl2 (0.3) were determined. The IQY
was found to be dependent on H+ concentration, due to competition with gem
inal recombination within the solvent cage. This dependence, and the effici
ency of energy transfer between excited iron(III) species and iron(II) in g
round state, are discussed.