Direct measurements of removal rates of CFCl(Ã1A″(0, 1, 0)) by simple alkenes

Direct measurements of rate constants for the collisional removal of CFCl(Ã1A″(0, 1, 0)) by ethylene (C2H4), propene (C3H6), 1-butene (1-C4H8), i-butene (i-C4H8) and 1,3-butadiene (C4H6) are reported. CFCl(Ã1A″(0, n, 0)) was prepared by infrared multiple photon dissociation (IRMPD) of CHFCl2 followed by tunable dye laser pumping at the transition CFCL(Ã1A″(0, 1, 0) ← X̃1A″(0, 1, 0)). Removal rates at threshold CO2-laser fluence for the gases ethylene, propene, 1-butene, 1,3-butadiene and i-butene were measured to be 1.4 ± 0.15, 3.7 ± 0.7, 2.2 ± 0.2, 4.0 ± 0.8 and 4.1 ± 0.4 in 10−11 cm3 molecule−1 s−1 units. An upper limit of the rate constant for physical quenching of CFCl(Ã) by Ar is also reported as < 1 × 10−13 cm3 molecule−1 s−1. The rate date are compared with those for reactions of other carbenes and the appropriate Parmenter-Seaver plot is presented.