Mechanistic and kinetics study on the reaction of CF₃CBrCH₂ with OH: A theoretical study

Abstract

Quantum chemical method (CCSD(T)/cc‐pVTZ//M06‐2X/6‐311++G(d,p)) is employed to research the CF3CBrCH2 + OH reaction. The results indicate that the reaction takes place through the interaction of the oxygen atom of the OH radical with the middle C and terminal C atom of CF3CBrCH2 generating adduct IM1 (CF3CBrCH2OH) and IM2 (CF3CBrOHCH2), respectively, and then further dissociation or rearrangement to many products. The rate constants have been computed at 10−10 to 1010 Torr and 200–3000 K by RRKM theory for various product pathways. The results show that at 200–800 K, the rate constant for the production of IM1 (CF3CBrCH2OH) by collisional deactivation is dominant; at high temperatures, the production of P1 (CF3CBrCHOH + H) becomes predominate. The predicted data for CF3CBrCH2 + OH agree closely with available experimental value. The total rate constants are independent on pressure and dependent on temperature. The rate equation can be fitted as k(T) = 1.77 × 10 −7T−0.65exp(−4518.77/T) at 200–300 K, 30 Torr of Ar. The atmospheric lifetime of CF3CBrCH2 in OH is around 2.77 days. TD‐DFT computations imply that IM1, IM2, IM3, IM4, IM5, and IM6 will photolyze under the sunlight.