Atmospheric chemistry of 1-methyl-2-pyrrolidinone

Rate constants for the atmospheric reactions of 1-methyl-2-pyrrolidinone with OH radicals, NO3 radicals and O3 have been measured at 296±2 K and atmospheric pressure of air, and the products of the OH radical and NO3 radical reactions investigated. Using relative rate techniques, rate constants for the gas-phase reactions of OH and NO3 radicals with 1-methyl-2-pyrrolidinone of (2.15±0.36)×10-11 cm3 molecule-1 s-1 and (1.26±0.40)×10-13 cm3 molecule-1 s-1, respectively, were measured, where the indicated errors include the estimated overall uncertainties in the rate constants for the reference compounds. An upper limit to the rate constant for the O3 reaction of <1×10-19 cm3 molecule-1 s-1 was also determined. These kinetic data lead to a calculated tropospheric lifetime of 1-methyl-2-pyrrolidinone of a few hours, with both the daytime OH radical reaction and the nighttime NO3 radical reaction being important loss processes. Products of the OH radical and NO3 radical reactions were analyzed by gas chromatography with flame ionization detection and combined gas chromatography–mass spectrometry. N-methylsuccinimide and (tentatively) 1-formyl-2-pyrrolidinone were identified as products of both of these reactions. The measured formation yields of N-methylsuccinimide and 1-formyl-2-pyrrolidinone were 44±12% and 41±12%, respectively, from the OH radical reaction and 59±16% and 4%, respectively, from the NO3 radical reaction. Reaction mechanisms consistent with formation of these products are presented.