Atmospheric Chemistry of n-CH2═CH(CH2) xCN ( x = 0-4): Kinetics and Mechanisms.

Smog chamber/Fourier transform infrared (FTIR) techniques were used to measure the kinetics of the reaction of n-CH2═CH(CH2) xCN ( x = 0-4) with Cl atoms, OH radicals, and O3: k(CH2═CHCN + Cl) = (1.03 ± 0.13) × 10-10, k(CH2═CHCH2CN + Cl) = (2.02 ± 0.35) × 10-10, k(CH2═CH(CH2)2CN + Cl) = (2.75 ± 0.45) × 10-10, k(CH2═CHCN + OH) = (4.21 ± 0.95) × 10-12, k(CH2═CHCH2CN + OH) = (1.55 ± 0.34) × 10-11, k(CH2═CH(CH2)2CN + OH) = (2.98 ± 0.64) × 10-11, k(CH2═CH(CH2)3CN + OH) = (3.34 ± 0.64) × 10-11, k(CH2═CH(CH2)4CN + OH) = (3.61 ± 0.85) × 10-11, k(CH2═CHCN + O3) = (2.55 ± 0.28) × 10-20, k(CH2═CHCH2CN + O3) = (1.17 ± 0.24) × 10-18, k(CH2═CH(CH2)2CN + O3) = (3.35 ± 0.69) × 10-18, k(CH2═CH(CH2)3CN + O3) = (4.07 ± 0.82) × 10-18, and k(CH2═CH(CH2)4CN + O3) = (7.13 ± 1.49) × 10-18 cm3 molecule-1 s-1 at a total pressure of 700 Torr of air or N2 diluents at 296 ± 2 K. CH2ClC(O)CN, HC(O)CN, HC(O)Cl, HCN, NCC(O)OONO2, and ClC(O)OONO2 were identified as products from the Cl initiated oxidation of CH2═CHCN. The product spectra were compared to experimental and theoretically calculated IR spectra. No products could be determined from the oxidation of n-CH2═CH(CH2) xCN ( x = 1-4). With the determined OH rate constants, the atmospheric lifetimes for n-CH2═CH(CH2) xCN ( x = 0-4) were estimated to be 66, 18, 9.3, 8.3, and 7.7 h, respectively. It was found that these unsaturated nitriles have no significant atmospheric environmental impact.