Room Temperature Rate Coefficients for the Reactions of OH Radicals with Some Monoethylene Glycol Monoalkyl Ethers

Rate coefficients for the reactions of OH radicals with monoethylene glycol monoalkyl ethers have been determined by the competitive method at 297 ± 3 K. Relative to the value k OH+hexanol = 12.5 × 10 -12 cm 3 molecule -1 s -1, the rate coefficients are as follows (in units of 10 -12 cm 3 molecule -1 s -1 ): methoxyethanol, 10.8 ± 1.1; ethoxyethanol, 14.5 ± 0.4; propoxyethanol, 16.4 ± 0.7; butoxyethanol, 19.4 ± 2.0. In a second set of experiments relative rate coefficients were measured for the same series of glycol ethers (TST) against heptanol. In all cases the values of k TST / k heptanol divided by k TST / k hexanol yielded values of k heptanol / k hexanol consistent with our experimentally determined value of k heptanol / k hexanol = 1.24 ± 0.08. The results are discussed with respect to literature data and structure activity relationships, and the tropospheric lifetimes of the glycol ethers are estimated.