TEMPERATURE-DEPENDENCE OF THE GAS-PHASE REACTION-RATES OF CF3O WITH METHANE, ETHANE, AND ISOBUTANE

The rates of the atmospherically important reactions of the CF3O radic al with methane (k(6)), ethane (k(7)), and isobutane (k(8)) have been measured at low pressure (approximate to 1 Torr) with the fast flow tu be technique associated with a monitoring of the CF3O radical by laser -induced fluorescence; over the following temperature ranges, the resp ective Arrhenius expressions are as follows: methane (296-573 K), k(6) (4.49 +/- 1.39) x 10(-12) exp(1606 +/- 84)/T cm(3) s(-1); ethane (295 -573 K), k(7) = (1.13 +/- 0.34) x 10(-11) exp-(642 +/- 113)/T cm(3) s( -1): isobutane (298-523 K), k(8) = (1.04 +/- 0.2) x 10(-11) exp-(102 /- 67)/T. A comparison with measurements with other techniques shows t hat, though our room temperature values of k(6), k(7), and k(8) are in very good agreement with most literature values, our temperature coef ficients for k(7) and k(8) are significantly different from the very f ew other measurements available in the literature. These discrepancies are tentatively ascribed to undetected wall reactions in the highest range of temperatures.