A Combined Experimental and Theoretical Study on the Gas Phase Reaction of OH Radicals With Ethyl Propyl Ether

The reaction of ethyl propyl ether (EnPE) with OH radicals was studied using proton-transfer-reaction mass spectrum (PTR-MS), and the rate constant was measured at 298 K and atmospheric pressure using the relative rate method: kexp(OH + EnPE) = (1.13 ± 0.09) × 10-11 cm3 molecules-1 s-1. In addition, a parallel theoretical study was performed using the traditional transition state theory (TST) with a tunnelling effect correction in combination at the M05-2X/aug-cc-pVTZ//M05-2X/6-311++G(d,p) level. According to these calculations, H-atom abstraction occurs more favourably from the methylene group adjacent to the -O- bond than from the other groups. The theoretical calculation of the total rate constant of the reaction of EnPE with OH radicals was consistent with the experimental values. The gas-phase products indicated that the major products observed were ethyl formate, ethyl propionate, and propionaldehyde. Combined with the experimental and theoretical results, the possible reaction mechanisms were propo...