Quantum chemical study of the (Z)-2-penten-1-ol (HOCH2–CH = CHCH2CH3) + OH + O2 reactions

Abstract

ABSTRACTThe mechanism and products of the reaction of (Z)-2-penten-1-ol [(Z)-PO21] with OH radical in the presence of O2 have been elucidated by using high-level quantum chemical methods CCSD(T)/6-311+G(d,p)//BH&HLYP/6-311++G(d,p). The calculations clearly indicate that addition channels contribute maximum to the total reaction and H-abstraction channels can be neglected at temperatures of 220–500 K. The rate constant for the reaction of OH radical with (Z)-PO21 at 298 K is computed to be 1.22 × 10−10 cm3 molecule−1 s−1, which is in stronger agreement with the previously reported experimental values. The kinetic data obtained over the temperature range 220−500 K are used to derive an non-Arrhenius expression: k = 3.69 × 10−13 × exp(1763.7/T) cm3 molecule−1 s−1. For the reaction of (Z)-PO21with OH radical in the presence of O2, the major primary reaction products found in this study are propanal [CH3CH2C(O)H] and glycolaldehyde [HOCH2C(O)H], whereas formaldehyde [HC(O)H], 2-hydroxybutanal [CH3CH2CH(OH)C(O)H] and the epoxide P18 are anticipated to be minor products. The calculated results are consistent with the recent experimental observations.