Photolysis of Sn(IV)Pc(OH)2 (Pc = phthalocyanine dianion) and Sn(IV)PC
(Cl)2 using a tungsten lamp, and in the presence of SnCl2 . 2H2O as an
electron donor result in the reduction of these complexes to pi anion
radical species. The reduction shows second order dependence on the c
oncentration of the Sn(IV)Pc complexes and a first order dependence on
SnCl2.H2O.