10min:

BRIAN E. APPLEGATE, MICHAEL B. PUSHKARSKY AND TERRY A. MILLER, The Ohio State University, Dept. of Chemistry, Laser Spectroscopy Facility, 120 W. 18th Avenue, Columbus, Ohio 43210.

Photodissociation in the ²A₁ state of the methylthio radical has been probed in a jet-cooled expansion by two techniques, fluorescence temporal decay and fluorescence depletion spectroscopy. The rate of photodissociation will be presented in terms of the total excitation energy as well as the vibrational mode excited based upon high resolution studies. There is evidence of mode selective photofragmentation with ₃ (C-O/S stretch) being a major promoting motion similar to earlier observations in methoxy.\footnotePowers D.~E.; Pushkarsky M.; and Miller T.~A., J. Chem. Phys. , 1997, 106 , 6863. However in contrast to CH₃O and other methoxy type radicals, in CH₃S ₂ (the umbrella motion) also appears to play an active role in the process leading to the breaking of the C-S bond. Additional comparisons to the recent photofragmentation spectroscopy of the methylthio radical by Neumark and coworkers\footnoteBise R.~T.; Choi H.; Pederson H.~B.; Mordaunt D.~H; and Neumark D.~M., J. Chem. Phys. , 1999, 110 , 805. will be made.