Kinetics of C 2H radical reactions with ethene, propene and 1-butene measured in a pulsed Laval nozzle apparatus at T=103 and 296 K

Abstract

Low-temperature kinetics of the reactions of C 2H radical with ethene ( k 1), propene ( k 2), and 1-butene ( k 3) are studied using a pulsed Laval nozzle supersonic expansion. The C 2H decay profiles in the presence of both the alkene reactant and O 2 are monitored by the CH(A 2 Δ) chemiluminescence tracer method. The rate constants k 1, k 2, and k 3 are measured at T=103 K to be (1.4±0.4)×10 −10, (2.4±0.6)×10 −10, and (2.6±0.6)×10 −10 cm 3 molecule −1 s −1 , respectively. Measurements at room temperature (296 K) and previous data suggest a slight negative temperature dependence for all three reactions.