A kinetic study of the reaction of Cl with a series of linear and ramified ketones as a function of temperature

The reactions of Cl atoms with 2,3-butadione (k(l)), 2-butanone (k(2)), 2-pentanone (k(3)) 2-hexanone (k(4)), 3-methyl-2-butanone (k(5)) 4-methyl-2-pentanone (k(6)) and 5-methyl-2-hexanone (k(7)) were investigated for the first time as a function of temperature (266-380 K), over the pressure range 20-200 Torr, using pulsed laser photolysis-resonance fluorescence (PLP-RF). The Arrhenius expressions for the seven reactions are proposed. The temperature dependence of the studied reactions is discussed; the reaction of Cl atoms with 2,3-butadione exhibits a positive temperature dependence whereas the corresponding reactions with 2-pentanone, 2-hexanone, 4-methyl-2-pentanone and 5-methyl-2-hexanone exhibit a negative temperature dependence and those with 2-butanone and 3-methyl-2-butanone shows only a slightly positive and a negative temperature dependence, respectively. Finally, the results and atmospheric implications are discussed and compared with the reactivity towards the OH radical.