Atmospheric chemistry of n‐ CH 3 (CH 2 ) x CN ( x = 0–3): Kinetics and mechanisms

Smog chamber/Fourier transform infrared (FTIR) techniques were used to measure the kinetics of the reaction of n‐ CH 3 (CH 2 ) x CN ( x  = 0–3) with Cl atoms and OH radicals: k (CH 3 CN + Cl) = (1.04 ± 0.25) × 10 −14 , k (CH 3 CH 2 CN + Cl)   = (9.20 ± 3.95) × 10 −13 , k (CH 3 (CH 2 ) 2 CN + Cl)   = (2.03 ± 0.23) × 10 −11 , k (CH 3 (CH 2 ) 3 CN + Cl)   = (6.70 ± 0.67) × 10 −11 , k (CH 3 CN + OH)   = (4.07 ± 1.21) × 10 −14 , k (CH 3 CH 2 CN + OH)   = (1.24 ± 0.27) × 10 −13 , k (CH 3 (CH 2 ) 2 CN + OH)   = (4.63 ± 0.99) × 10 −13 , and k (CH 3 (CH 2 ) 3 CN + OH) = (1.58 ± 0.38) × 10 −12 cm 3 molecule −1 s −1 at a total pressure of 700 Torr of air or N 2 diluents at 296 ± 2 K. The atmospheric oxidation of alkyl nitriles proceeds through hydrogen abstraction leading to several carbonyl containing primary oxidation products. HC(O)CN, NCC(O)OONO 2 , ClC(O)OONO 2 , and HCN were identified as the main oxidation products from CH 3 CN, whereas CH 3 CH 2 CN gives the products HC(O)CN, CH 3 C(O)CN, NCC(O)OONO 2 , and HCN. The oxidation of n‐ CH 3 (CH 2 ) x CN ( x  = 2–3) leads to a range of oxygenated primary products. Based on the measured OH radical rate constants, the atmospheric lifetimes of n‐ CH 3 (CH 2 ) x CN ( x  = 0–3) were estimated to be 284, 93, 25, and 7 days for x  = 0,1, 2, and 3, respectively.