Photofragmentation dynamics of the thiomethoxy radical

The radiative and nonradiative decay of the (A) over tilde E-2 electronic s tate of the CH3S radical has been investigated using a variety of experimen tal techniques. Lifetimes have been measured for a number of vibrational le vels; these data have been analyzed along with similar results previously o btained for other methoxy radical family members, CH3O, CD3O, and CF3S. It is concluded that the totality of the data is best described by a model whi ch postulates mode-selective fragmentation into a methyl (or fluoromethyl) radical and an O or S atom. For CH3S there appears a second nonradiative de cay channel, possibly producing H + CH2S. (C) 2000 American Institute of Ph ysics. [S0021-9606(00)00237-3].