Near-UV Photodissociation Dynamics of Thiomethoxy Radical via A~2A_1 State:H-atom Product Channel

摘要

Photodissociation dynamics of jet-cooled thiomethoxy radical(CH3S)via the A~2A_1<-X~2E transition is investigated near 352 nm.The H-atom product channel is observed directly for the first time by H-atom product yield spectrum and photofragment translational spectroscopy.The 2~13~2 vibrational level of the A~2A_1 state dissociates to the H4-H2CS products.The H+H2CS product translational energy release is modest and peaks around 33 kJ/mol;the H-atom angular distribution is isotropic.The dissociation mechanism is consistent with internal conversion of the excited A~1A_1 state to the X~2E ground state and subsequent unimolecular dissociation on the ground state to the H+H2CS products.