Gas phase reactions of C1–C4 alcohols with the OH radical: A quantum mechanical approach
CCSD(T)//BHandHLYP/6-311G(d,p) calculations have been performed to study the OH hydrogen abstraction reaction from C1–C4 aliphatic alcohols. A complex mechanism involving the formation of a stable pre-reactive complex is proposed and the temperature dependence of the rate coefficients is studied over the temperature range of 290–500 K, using conventional transition state theory (CTST). Excellent agreement between calculated and experimental k at 298 K has been obtained. Arrhenius expressions are proposed for 1-propanol and 1-butanol, k1-Prop = 3.06 × 10−12exp(140/T) and k1-But = 2.14 × 10−12exp(440/T) cm3 molecule−1·s−1, respectively. The rate coefficient for the formation of the alpha radical is found significantly larger than that of the competing channels for C1–C3 alcohols. The finding that at room temperature the rate constant of 1-butanolγ is the largest one supports some of the previous experimental results.