Atmospheric chemistry of 1-methyl-2-pyrrolidinone

Abstract

Rate constants for the atmospheric reactions of 1-methyl-2-pyrrolidinone with OH radicals, NO 3 radicals and O 3 have been measured at 296±2 K and atmospheric pressure of air, and the products of the OH radical and NO 3 radical reactions investigated. Using relative rate techniques, rate constants for the gas-phase reactions of OH and NO 3 radicals with 1-methyl-2-pyrrolidinone of (2.15±0.36)×10 -11 cm 3 molecule -1 s -1 and (1.26±0.40)×10 -13 cm 3 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 O 3 reaction of <1×10 -19 cm 3 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 NO 3 radical reaction being important loss processes. Products of the OH radical and NO 3 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 NO 3 radical reaction. Reaction mechanisms consistent with formation of these products are presented.