“Tropospheric Photo-Oxidation of Ethyl Methacrylate Initiated by Cl Atoms in the Gas Phase: Kinetic and Mechanistic Investigations”
A. Kumar & B. Rajakumar. ACS Earth Space Chem. 2020.(Just Accepted!)


The photo-oxidation reaction of ethyl methacrylate (EMA) initiated by Cl (R1) atoms were explored in the Earth’s tropospheric conditions using experimental as well as computational methodologies. The experiments were performed to measure the rate coefficients of the title reaction over the temperature range of 268 – 363 K by the relative rate method. The rate coefficients for R1 were measured relative to 1, 3 butadiene and trans-2-butene. The rate coefficient for R1 at 298K was experimentally measured to be k_(EMA+Cl)^(Exp-298 K)= (2.80 ± 0.80) × 10-10 cm3 molecule-1 s-1. The derived Arrhenius expression for the title reaction is k_(TFEA+Cl)^(Exp-(268-363K))= (2.32 ± 0.20) × 10-11 exp [(696 ± 54)/T]. Computational calculations were performed at CCSD(T)//MP2/6-31+G(d, p) level of theory using Canonical Variational Transition state theory (CVT) with Small Curvature Tunneling (SCT) in the temperatures between 200 and 400K. The degradation mechanism initiated by Cl atoms was proposed for R1 based on the qualitative analysis of the products. The important atmospheric parametrers such as atmospheric lifetimes, global warming potentials and photochemical ozone creation potentials, thermochemistry and branching ratios of R1 are presented in the manuscript.