Gas Phase OH Radical Reaction with 2‐Chloroethyl Vinyl Ether in the 256–333 K Temperature Range: A Combined LP‐LIF and Computational Study

Abstract

AbstractThe absolute rate coefficient for the gas phase reaction of OH radical with 2‐chloroethyl vinyl ether (H2C=CH–O–CH2CH2Cl, 2ClEVE) has been measured using the laser photolysis (LP) – laser induced fluorescence (LIF) technique. The kinetics measurements were done over the temperature range of 256–333 K. The bimolecular rate coefficients obtained, k(T), showed Arrhenius type behaviour which were fitted to the expression k(T)=(4.18±0.55)×10−12 exp[(700±70)/T] cm3 molecule−1 s−1. The room temperature rate coefficient shows pressure independent behaviour in the range of 10–40 Torr. The reaction shows weak negative temperature dependence. A detail computational studies involving the energies and structures of the reactants, transition states and products were performed using Complete Basis Set (CBS) and Quadratic Configuration Interaction with Single and Double substitutions with a Triples contribution to the energy, QCISD(T), method to elucidate the reaction mechanism. The results suggest that the major pathways for the reaction proceeds through addition of OH radical to the C=C double bond and the H atom abstraction from the –O–CH2– group and they are competitive in nature. The tropospheric lifetime, radiative efficiency (RE) and the global warming potential (GWP) for 2‐chloroethyl vinyl ether (2ClEVE) have been also determined.