Kinetics and products of the reactions of selected diols with the OH radical

Using a relative rate method, rate constants have been measured at 296 +/- 2 K for the gas-phase reactions of OH radicals with 1,2-butanediol. 2,3-butanediol, 1,3-butanediol, and 2-methyl-2,4-pentanediol. with rate constants tin units of 10(-12) cm(3) molecule(-1) s(-1)) of 27.0 +/- 5.6. 23.6 +/- 6.3. 33.2 +/- 6.8. and 27.7 +/- 6.1. respectively, where the error limits include the estimated overall uncertainty of +/-20% in the rate constant for the reference compound. Gas chromatographic analyses showed the formation of 1-hydroxy-2-butanone from 1,2-butanediol. 3-hydroxy-2-butanone from 2,3-butanediol. 1-hydroxy-3-butanone from 1,3-butanediol, and 4-hydroxy-4-methyl-2-pentanone from 2-methyl-2,4-pentanediol, with formation yields cf 0.66 +/- 0.11, 0.89 +/- 0.09. 0.50 +/- 0.09, and 0.47 +/- 0.09. respectively, where the indicated errors are the estimated overall uncertainties. Pathways for the formation of these products are presented, together with a comparison of the measured and estimated rate constants and product yields (C) 2001 John Wiley & Sons, Inc