Relative and absolute kinetic studies of 2-butanol and related alcohols with tropospheric Cl atoms

A newly constructed chamber/Fourier transform infrared system was used to determine the relative rate coeffcient, k(i), for the gas-phase reaction of Cl atoms with 2-butanol (k(1)), 2-methyl-2-butanol (k(2)), 3-methyl-2-butanol (k(3)), 2,3-dimethyl-2-butanol (k(4)) and 2-pentanol (k(5)). Experiments were performed at (298 +/- 2) K, in 740 Torr total pressure of synthetic air, and the measured rate coefficients were, in cm 3 molecule(-1) s(-1) units (+/- 2 sigma): k1 (1.32 +/- 0.14) x 10(-10), k(2) = (7.0 +/- 2.2) x 10(-11), k(3) = (1.17 +/- 0.14) x 10(-10), k(4) = (1.03 +/- 0.17) x 10(-10) and k5 (2.18 +/- 0.36) x 10(-10), respectively. Also, all the above rate coefficients (except for 2-pentanol) were investigated as a function of temperature (267 -384 K) by pulsed laser photolysis -resonance fluorescence (PLP-RF). The obtained kinetic data were used to derive the Arrhenius expressions: k(1)(T) = (6.16 +/- 0.58) x 10(-11) exp[(174 +/- 58)/T], k(2)(T) (2.48 +/- 0.17) x 10(-11) exp[(328 +/- 42)/T], k(3)(T) (6.29 +/- 0.57) x 10(-11) exp[(192 +/- 56)/T], and k(4)(T) (4.80 +/- 0.43) x 10(-11) exp[(221 +/- 56)/T] (in units of cm(3) molecule(-1) s(-1) and +/- sigma). Results and mechanism are discussed and compared with the reported reactivity with OH radicals. Some atmospheric implications derived from this study are also reported.