Heterogeneous effects on the thermal and photoreactivities of tris(1,2-diaminoethane)chromium(III) cation and hexathiocyanatochromate(III) anion in aqueous media

The ground- and excited-state reactivities of the [Cr- (en)3]3+ (en=1,2-diaminoethane) and [Cr(NCS)6]3− ions in a polyacrylamide (PAA) environment are reported. The aquation kinetics of these complexes has been studied to identify the effect of added PAA with varying molecular weight. Aquation of the complexes in aqueous acid containing PAA yielded the respective substituted products. The macromolecule in solution was found to decrease significantly the rate of ligand replacement. Similarly, photolysis of the cationic and anionic complexes in water–PAA mixtures revealed a decrease in aquation quantum yield. Possible explanations for the decrease in reaction rates and quantum yields are discussed. This revised version was published online in June 2006 with corrections to the Cover Date.