The hydroxyl radical reaction rate constant and products of cyclohexanol

The gas phase reaction of the hydroxyl radical (OH) with cyclohexanol (COL) has been studied. The rate coefficient was determined to be (19.0 +/- 4.8) X 10(-12) cm(3) molecule(-1) s(-1) (at 297 +/- 3 K and 1 atmosphere total pressure) using the relative rate technique with pentanal, decane, and trid ecane as the reference compounds. Assuming an average OH concentration of 1 x 10(6) molecules cm(-3), an atmospheric lifetime of 15 h is calculated fo r cyclohexanol. Products of the OH + COL reaction were determined to more c learly define COL's atmospheric degradation mechanism. The observed product s and their Formation yields were: cyclohexanone (0.55 +/- 0.06), hexanedia l (0.32 +/- 0.15), 3-hydroxycyclohexanone (0.31 +/- 0.14), and 4-hydroxycyc lohexanone (0.08 +/- 0.04). Consideration of the potential reaction pathway s suggests that each of these products is formed via hydrogen abstraction a t a different site on the COL ring. The products and their relative amounts are discussed in light of the predicted yields For each reaction channel. (C) 2001 lohn Wiley C Sons, Inc.