ChemInform Abstract: Photoinduced Water Exchange of the Isomeric Ammineaquachromium(III) Complexes, and Mechanism of Solvent‐Assisted Excited State Deactivation.

Abstract

030ChemInform Abstract The photoinduced H2O exchange reactions of the eight possible (Cr(NH3)6-n(OH2)n)3+ (n = 0-6) complexes have been studied in 1 M perchlorate medium (25 rc C, 546 nm irradiation) using 18O-labelling. The photochemical reactivity is dominated y exchange of coordinated H2O, but decreases rapidly with increasing number of H2O ligands. The product distributions are best explained by an associativeinterchange mechanism and trans-attack of the entering H2O molecule to give a pentagonal-bipyramidal transition tate. Based on ligand field model calculations, the mechanism is discussed in detail.