Reaction of hydroxyl radical with acetone.: 1.: Kinetics of the reactions of OH, OD, and 18OH with acetone and acetone-d6

The rate coefficient for the reaction of OH with acetone, k(1), was measured by producing OH via pulsed laser photolysis and detecting it via laser-induced fluorescence to be k(1)(T) = 1.38 x 10(-13) + 3.86 x 10(-11) exp(-1997/T) cm(3) molecule(-1) s(-1). These results confirm the rate coefficient data of Wollenhaupt et al. (J. Phys. Chem. A 2000, 104, 2695). A value of k(1) suitable for atmospheric calculations is deduced from our data and that from previous work to be k(1) = 1.39 x 10(-13) + 3.72 x 10(-11) exp(-2044/T) cm(3) molecule(-1) s(-1). The rate coefficients at 298 K for the reaction of OH with CD3C(O)CD3 (k(4)), OD with CH3C(O)CH3 (k(2)), and OD with CD3C(O)CD3 (k(5)) were measured to be (in units of cm(3) molecule(-1) s(-1)) (3.00 +/- 0.04) x 10(-14), (2.07 +/- 0.14) x 10(-13), and (3.26 +/- 0.16) x 10(-14), respectively; they were also measured at a few temperatures above and below 298 K. It was deduced that the reaction of (OH)-O-18 with acetone does not produce (OH)-O-16. The large primary kinetic isotope effect (i.e., the large value of k(1)/k(4) and k(2)/k(5)) at 298 K and its increase with decreasing temperature suggests that OH abstracts an H atom from acetone. k(1) was found to be independent of bath gas pressure between 1 and 490 Torr and independent of bath gas (He, N-2, or SF6). The products and mechanism of the OH-acetone reaction is discussed in the companion paper.