Absolute Rate Constants for the Reactions of Cl Atoms with a Series of Esters

Absolute rate coefficient measurements have been carried out for the Cl atom reaction with a series of esters, at room temperature (298 ± 2 K) and in the pressure range 15−60 Torr, using the laser photolysis−resonance fluorescence technique. The rate coefficients obtained (in units of cm 3 molecule -1 s -1 ) are as follows: methyl formate (1.83 ± 0.21) × 10 -12, ethyl formate (1.34 ± 0.15) × 10 -11, n -propyl formate (5.63 ± 0.65) × 10 -11, n -butyl formate (1.41 ± 0.17) × 10 -10, methyl acetate (2.85 ± 0.35) × 10 -12, ethyl acetate (2.01 ± 0.25) × 10 -11, n -propyl acetate (7.76 ± 0.92) × 10 -11, n -butyl acetate (1.74 ± 0.20) × 10 -10, isopropyl acetate (2.68 ± 0.34) × 10 -11, isobutyl acetate (1.08 ± 0.13) × 10 -10, tert -butyl acetate (2.42 ± 0.28) × 10 -11, sec -butyl acetate (9.1 ± 1.0) × 10 -11, methyl propionate (1.98 ± 0.26) × 10 -11, methyl butyrate (8.6 ± 0.9) × 10 -11, methyl valerate (1.7 ± 0.2) × 10 -10, and methyl caproate (2.72 ± 0.32) × 10 -10 . The results are discussed in terms of structure−reactivity relationship.