Kinetic Investigations on the Gas Phase Reaction of 2,2,2-Trifluoroethylbutyrate with OH Radicals: An Experimental and Theoretical Study

The temperature dependent rate coefficients for the reaction between 2,2,2-trifluoroethylbutyrate (2,2,2-TFEB) with OH radicals were measured as a function of temperature (268-343 K) and pressure (400-760 Torr; N-2 and O-2) using relative rate technique. The temperature dependent rate coefficients for the gas phase reaction of 2,2,2-TFEB + OH were used to deduce the Arrhenius expression: k(268-343 K) = (2.72 +/- 1.3) x 10(-13) exp{(530 +/- 72)/T}cm(3) molecule(-1) s(-1). At 298 K, the rate coefficient for the title reaction was obtained to be (1.58 +/- 0.42) x 10(-12) cm(3) molecule(-1) s(-1). Extensive computational calculations were also performed as a complement to the present experimental study using canonical variational transition state theory (CVT) with small curvature tunnelling (SCT) correction in combination with the CCSD(T)/CC-PVDZ//M062X/6-31+G(d,p) level of theory. The atmospheric lifetime of the test molecule due to its reaction with OH radical is about 3 days, which is short lived. And therefore, its contribution towards the global warming potentials can be insignificant. The ozone formation potential of the test molecule is calculated to be 0.229 ppm, which is again negligible.