Kinetics of the Gas-Phase Reactions of OH and NO3 Radicals and O3 with Allyl Alcohol and Allyl Isocyanate

Abstract

Rate constants for the gas-phase reactions of OH radical, NO(3) radical, and ozone with allyl alcohol (AAL) and allyl isocyanate (AIC) have been measured using relative rate methods at atmospheric pressure in purified air. The experimental Arrhenius expression obtained for the reaction of the OH radical with AAL is (1.68 +/- 0.89) x 10(-12) x exp(1100/T) cm(3) molecule(-1) s(-1), for T = 282-315 K; the Arrhenius expression for the reaction of OH radical with AIC is (1.94 +/- 1.04) x 10(-14) x exp(2207/T) cm(3) molecule(-1) s(-1), for T = 282-317 K, where the indicated errors are one least-squares standard deviation. All OH radical reaction rate constants have been measured relative to k(OH + alpha-pinene) and k(OH + 1,3,5-trimethylbenzene). The rate constant for the gas-phase reaction of OH radical with allyl alcohol-d(6) isotopomer (AAL-d(6)) has been measured at T = 298 K, and the value is 5.10 x 10(-11) cm(3) molecule(-1) s(-1). The kinetic isotope effect is small, with k(AAL)/k(AAL-d(6)) = 1.32. Rate constants for the gas-phase reactions of NO(3) radical with AAL [relative to k(NO(3) +methacrolein)] and O(3) [relative to k(O(3) + beta-pinene)] have been measured, and the values are 7.7 x 10(-15) cm(3) molecule(-1) s(-1) at T = 298 K and 1.6 x 10(-17) cm(3) molecule(-1) s(-1) at T = 296 K, respectively. Rate constants for the gas-phase reactions of NO(3) radical and O(3) with AIC have been measured, and the values are 9.4 x 10(-16) cm(3) molecule(-1) s(-1) at T = 299 K and 5.54 x 10(-18) cm(3) molecule(-1) s(-1) at T = 299 K, respectively. Multireference ab initio calculations at the MRMP2/6-311G(d,p) level have been carried out for reactions of OH radical with AAL and AIC. Results indicate that prereactive hydrogen bonded complexes form in the entrance channels for these reactions.