The photochemistry of (η 6-anisole)Cr(CO) 3 and (η 6-thioanisole)Cr(CO) 3 was investigated by picosecond time-resolved infrared spectroscopy in n-heptane solution at 298 K. Two independent excited states are populated following 400 nm excitation of each of these complexes. An excited state with some metal-to-CO charge-transfer character is responsible for the CO-loss process, which is slow compared to CO-loss from Cr(CO) 6. Observed first order rate constants of 1.8 × 10 10 s -1 and 2.5 × 10 10 s -1 were obtained for the anisole and thioanisole complexes, respectively. The second excited state has metal-to-arene charge transfer character and results in a haptotropic shift of the thioanisole ligand. DFT calculations characterized the excited states involved and the nature of the haptotropic shift intermediate observed for the thioanisole species.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry