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

Abstract

Direct measurements of rate constants for the collisional removal of CFCl(Ã 1A″(0, 1, 0)) by ethylene (C 2H 4), propene (C 3H 6), 1-butene (1-C 4H 8), i-butene ( i-C 4H 8) and 1,3-butadiene (C 4H 6) are reported. CFCl(Ã 1A″(0, n, 0)) was prepared by infrared multiple photon dissociation (IRMPD) of CHFCl 2 followed by tunable dye laser pumping at the transition CFCL( A ̃ 1 A″(0, 1, 0) ← X ̃ 1 A″(0, 1, 0)) . Removal rates at threshold CO 2-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 cm 3 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 cm 3 molecule −1 s −1. The rate date are compared with those for reactions of other carbenes and the appropriate Parmenter-Seaver plot is presented.