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'-bipyrid yl, 4,4'-dimethyl-2,2'-bipyridyl and 1,10-phenanthroline) with arylthi oacetic acids in acetonitrile and arylthioacetate ions in aqueous medi a have been studied. The substantial difference in ks values between t he acetonitrile and aqueous media Is traced to the difference in the o rigin of electron for the reduction of Cr(III) complexes i.e., sulphur in acetonitrile and carboxylate ion in aqueous medium.