Rate Constants and Vinoxy Product Yield in the Reaction OH + Ethylene Oxide

Absolute rate constants and the vinoxy (CH 2 CHO) product yield for the reaction of OH radicals with ethylene oxide (C 2 H 4 O) have been determined using a combined laser photolysis/resonance fluorescence (laser induced fluorescence) technique. The rate constant for OH decay is k 1 = (1.1 ± 0.4)‐ 10 −11 exp[‐(1460 ± 150) K/ T ] cm 3 /s over the temperature range T = 298–435 K. The branching ratio for vinoxy (VO) formation at 298 K is found to be ϕ vo = 0.08 and 0.23 at 13 and 80 mbar, respectively. A potential energy scheme accounting for reagent ring opening and the formation of vinoxy is presented.