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

Photochemistry and Photophysics of Chromium(III) Complexes

“…Many Cr(III) photosubstitution reactions occur with stereochemical change, and although some authors have referred to this merely as photoisomerization accompanying substitution, the evidence just discussed shows that this usually results from the symmetry-controlled concerted substitution process illustrated in Figure . The water exchange with stereochemical change seen ,,, in aquaam(m)ine complexes mimics simple isomerizations. However, the concern of this section is to deal with the other photoisomerizations that are found and to explore their mechanisms.…”

“…The extensive studies of photoaquation, 18 OH 2 exchange, and isomerization in the Cr(NH 3 ) x (H 2 O) 6 - x 3+ complexes ,, and some of their 1,3-propanediamine analogues have established that substitution of a water ligand competes very strongly with aquation of an ammonia ligand. Hence, some of the complexes that would be predicted to lose ammonia by the AOM instead substitute water preferentially.…”