Atmospheric fate of methyl vinyl ketone and methacrolein

Abstract

The rate coefficients for the reaction of OH with methyl vinyl ketone (MVK, CH3C(O)CHCH2) and methacrolein (MACR, CH2C(CH3)CHO) between 232 and 378 K were measured using the pulsed laser photolysis-pulsed laser induced fluorescence (PP-PLIF) technique. The rate coefficient data can be expressed in the Arrhenius form as k1(OH + MVK) = (2.67 ± 0.45) × 10-12 exp((452 ± 130)/ T) and k2(OH + MACR) = (7.73 ± 0.65) × 10-12 exp((379 ± 46)/T) cm3 molecule-1 s-1, where the error limits are 2σ and include estimated systematic errors. The UV absorption cross-sections of MVK and MACR were measured over the wavelength range 250-395 nm using a diode array spectrometer. Absolute quantum yields for loss of MVK and MACR were measured at 308, 337, and 351 nm. The MACR quantum yield, ΦMACR, was <0.01. The MVK quantum yield was both pressure and wavelength dependent and is represented by the expression: Φ0(λ,P)