Rate coefficients for the OH+CF3I reaction between 271 and 370 K

The rate coefficient, k(1), for the reaction OH + CF3I --> products was mea sured under pseudo-first-order conditions in hydroxyl radical, OH. OH tempo ral profiles were monitored by laser-induced fluorescence (LIF), and CF3I c oncentrations were determined by UV/Visible absorption. We determined k(1) (T) to be (2.10 +/- 0.80) x 10(-11) exp[-(2000 +/- 140)/T] cm(3) molecule(- 1) s(-1), over the temperature range 271 to 370 K. The quoted uncertainties are 2 sigma (95% confidence limits, sigma(A) = A sigma(lnA)) Previous meas urements of k(1)(T) are compared with our values, and possible reasons for the discrepancies are discussed. The heat of formation of HOI is deduced to be less than -16 kcal mole(-1), if the products of reaction 1 are mostly H OI and CF3. These measurements support the earlier conclusion that the reac tion of OH with CSI plays a negligibly small role in the atmospheric remova l of CF3I.