Absolute rate constants have been measured for the gas phase reactions of hydroxyl radicals with a series of aliphatic acetates:  methyl acetate (k 1), ethyl acetate (k 2), n-propyl acetate (k 3), n-butyl acetate (k 4), and n-pentyl acetate (k 5). Experiments were carried out using the pulsed laser photolysislaser induced fluorescence technique over the temperature range 243−372 K. The obtained kinetic data were used to derive the Arrhenius expressions, and since the Arrhenius plots were slightly curved they were fitted, using a three-parameter expression. The Arrhenius expressions obtained are:  k 1 = (0.53 ± 0.09) × 10-12 exp[−(128 ± 102)/T] ; k 2 = (0.48 ± 0.09) × 10-12 exp[(397 ± 103)/T]; k 3 = (1.03 ± 0.12) × 10-12 exp[(370 ± 69)/T] ; k 4 = (2.10 ± 0.28) × 10-12 exp[(299 ± 81)/T], and k 5 = (2.75 ± 0.46) × 10-12 exp[(302 ± 102)/T] (in units of cm3 molecule-1 s-1). At room temperature, the rate constants obtained (in units of 10-12 cm3 molecule-1 s-1) were as follows:  methyl acetate, 0.32 ± 0.03; ethyl acetate, 1.67 ± 0.22; n-propyl acetate, 3.42 ± 0.26 ; n-butyl acetate, 5.52 ± 0.51; n-pentyl acetate, 7.34 ± 0.91. Our results are compared with the previous determinations and discussed in terms of structure−activity relationships.

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