PHOTOREDOX REACTIONS OF POLYPYRIDYL CHROMIUM(III) COMPLEXES WITH ARYLTHIOACETIC ACIDS IN ACETONITRILE AND AQUEOUS-MEDIA

The reductive quenching reactions of *Cr(NN)(3)(3+) (NN = 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl and 1,10-phenanthroline) with arylthioacetic acids in acetonitrile and arylthioacetate ions in aqueous media have been studied. The substantial difference in ks values between the acetonitrile and aqueous media Is traced to the difference in the origin of electron for the reduction of Cr(III) complexes i.e., sulphur in acetonitrile and carboxylate ion in aqueous medium.