ULTRAFAST INVESTIGATION OF VIBRATIONAL-RELAXATION AND SOLVENT COORDINATION FOLLOWING PHOTODISSOCIATION OF CR(CO)(6)

Picosecond time-resolved resonance Raman spectroscopy has been used to study the photochemistry of Cr(CO)(6) in cyclohexane following photoe xcitation at 266 nm. Photodissociative loss of CO is found to occur wi thin our pulse width of less than or equal to 5 ps by probing the 533 cm(-1) vibrational mode of ground state Cr(CO)(6). The subsequent dyna mics after photodissociation are interpreted in terms of solvation, vi brational and electronic relaxations. The vibrational relaxation time of 100 ps and 83 ps are observed by monitoring nu=0 and nu=1 of the 38 1 cm(-1) transient mode, respectively. No evidence was found for solva tion and electronic relaxation occurring on a time scale of greater th an or equal to 5 ps.