Rate coefficients for the gas-phase reaction of OH with (<i>Z</i>)-3-hexen-1-ol, 1-penten-3-ol, (<i>E</i>)-2-penten-1-ol, and (<i>E</i>)-2-hexen-1-ol between 243 and 404 K

Abstract

Abstract. Rate coefficients, k, for the gas-phase reaction of the OH radical with (Z)-3-hexen-1-ol (Z)-CH3CH2CH = CHCH2CH2OH) (k1), 1-penten-3-ol (CH3CH2CH(OH)CH = CH2) (k2), (E)-2-penten-1-ol ((E)-CH3CH2CH = CHCH2OH) (k3), and (E)-2-hexen-1-ol ((E)-CH3CH2CH2CH = CHCH2OH) (k4), unsaturated alcohols that are emitted into the atmosphere following vegetation wounding, are reported. Rate coefficients were measured under pseudo-first-order conditions in OH over the temperature range 243–404 K at pressures between 20 and 100 Torr (He) using pulsed laser photolysis (PLP) to produce OH radicals and laser induced fluorescence (LIF) to monitor the OH temporal profile. The obtained rate coefficients were independent of pressure with negative temperature dependences that are well described by the Arrhenius expressions k1(T) = (1.3 ± 0.1) × 10−11 exp[(580 ± 10)/T]; k1(297 K) = (1.06 ± 0.12) × 10−10 k2(T) = (6.8 ± 0.7) × 10−12 exp[(690 ± 20)/T]; k2(297 K) = (7.12 ± 0.73) × 10−11 k3(T) = (6.8 ± 0.8) × 10−12 exp[(680 ± 20)/T]; k3(297 K) = (6.76 ± 0.70) × 10−11 k4(T) = (5.4 − 0.6) × 10−12 exp[(690 ± 20)/T]; k4(297 K) = (6.15 ± 0.75) × 10−11 (in units of cm3 molecule−1 s−1). The quoted uncertainties are at the 2σ (95% confidence) level and include estimated systematic errors. The rate coefficients obtained in this study are compared with literature values where possible.