Journal of Chemical Physics, Vol.121, No.12, 5868-5873, 2004
Photodissociation studies of CBr4+ and CBr3+ at 267 nm using ion velocity imaging
Time-of-flight (TOF) mass spectroscopy and ion velocity imaging were employed to study the formation and photodissociation of CBr4+ and CBr3+ ions that were observed in the TOF spectrum when a CBr4 beam was irradiated with 118 nm and 355 nm lasers. Energy dependence measurements show that both CBr4+ and CBr3+ ions depend on the fourth power of the 355 nm laser energy, which indicates that direct ionization and dissociative ionization of CBr4 have low probabilities from the state initially excited at 118 nm. This is likely due to the large geometry change in the CBr4+ ion. Two ionic fragments Br+ and CBr2+ were observed from the dissociation of CBr4+ and CBr3+ ions when another laser at 267 nm was introduced to the interaction region at a delayed time. The possible dissociation pathways and the angular and translational distributions are discussed in the paper. (C) 2004 American Institute of Physics.