Kinetics of the Gas-Phase Reactions of OH and NO_3Radicals and O_3with Allyl Alcoholand Allyl Isocyanate

摘要

Rate constants for the gas-phase reactions of OH radical, NO_3radical, and ozone with allyl alcohol (AAL)and allyl isocyanate (AIC) have been measured using relative rate methods at atmospheric pressure in purifiedair. The experimental Arrhenius expression obtained for the reaction of the OH radical with AAL is (1.68 ±0.89)×10~(-12) ×exp(1100/T) cm~3molecule~(-1) s~(-1), forT =282-315 K; the Arrhenius expression for thereaction of OH radical with AIC is (1.94±1.04) × 10~(-14) exp(2207/T) cm~3molecule~(-1)forT =282-317 K, where the indicated errors are one least-squares standard deviation. All OH radical reaction rateconstants have been measured relative to k(OH + α-pinene) and k(OH + 1,3,5-trimethylbenzene). The rateconstant for the gas-phase reaction of OH radical with ally! alcohol-d_6 isotopomer (AAL-d_6) has been measured at T = 298 K, and the value is 5.10 × 10~(-11)cm~3molecule~(-1)s~(-1).The kinetic isotope effect is small, withk(AAL)/k(AAL-d_6) = 1.32. Rate constants for the gas-phase reactions of NO_3radical with AAL [relative tok(NO_methacrolein)] and O_3[relative to k(3+ β-pinene)]have been measured, the values are 7.7 ×10~(-15)cm~3molecule~(-1) s~(-atT =298 K and 1.6 × 10~(-17)296 K, respectively. Rateconstants for the gas-phase reactions of NO_3radical and O_3with AIC have been measured, the values are9.4 × 10~(-16) cm~3molecule~(-1) s~(-atT =299 K and 5.54 × 10~(-18) cm~K, respectively.Multireference ab initio calculations at the MRMP2/6-311G(d,p) level have been carried out for reactions ofOH radical with AAL and AIC. Results indicate that prereactive hydrogen bonded complexes form in theentrance channels for these reactions.