Kinetics of the reaction between methyl radical and acetylene

Abstract

The reaction CH 3 +C 2 H 2 → C 3 H 4 +H (reaction 1) has been studied using laser photolysis/photoionization mass spectrometry. Rate constants were determined in time-resolved experiments as a function of temperature (750–1000 K). Rate constants of reaction 1 are independent of the bath gas density within the experimental range [M]=[He]+[C 2 H 2 ]=(6-24)×10 16 molecules cm −3 , C 3 H 4 was defected as a primary product of reaction 1. Within the 800–1000 K range of temperatures and bath gas densities, the rate constants of reaction 1 can be described by the Arrhenius expression k 1 =(6.3±2.9)×10 −13 exp(−(5011±422)K/ T ) cm 3 molecule −1 s −1 . The experimental results of the current study are compared with computational predictions based on models existing in the literature. New RRKM models based on the experimental data are created and used to extrapolate the results of the current study to higher temperatures.