2-COLOR MULTIPHOTON DECOMPOSITION OF 1-BROMO 8-FLUOROETHANE

Multiphoton decomposition of I-bromo 2-fluoroethane (CH2BrCH2F, BFE) w ith a two-color CO2 infrared laser is reported as a function of number of laser pulses. For single color irradiation at a wavelength chosen to excite BFE, the decomposition product, vinyl fluoride, which accumu lates during the many-pulse MPD experiment, is found to deactivate BFE decomposition. When a second laser, tuned to a vinyl fluoride absorpt ion is introduced, coincident with the First, the vinyl fluoride is fo und to activate further BFE decomposition. These results are accounted for in terms of a pressure-dependent model. Changes in model paramete rs, upon addition of the second laser, are shown to be consistent with interpretations in terms of collision-dependent reaction schemes. (C) 1994 John Wiley and Sons, Inc.