Ab initio MO studies on the photodissociation of the methoxy family CX3Y (X  H, F; Y  O, S) from the Ã2A1 state

Ab initio MO calculations have been carried out for the photodissociation of the methxy radical family CX3Y (X  H, F; Y  O, S) from the Ã2A1 state. Three channels are considered: (1) predissociation to CX3 + Y, (2) isomerization to CX2−YX followed by dissociation to CX2 + YX, and (3) dissociation of X giving CX2Y + X. Minima on the seam of crossing (MSXs) between the bound 2A1 state and 2A2, 4A2 and 4E repulsive states as well as transition states on each surface are located. The branching to the three channels is discussed based on the energetics of these critical points. Final internal energy distribution is briefly discussed based on the meta-intrinsic reaction coordinate.