Reaction of O(3P) with the alkyl iodides:: CF3I, CH3I, CH2I2, C2H5I, 1-C3H7I and 2-C3H7I

The kinetics of the reactions between O(P-3) and various alkyl iodides (RI) was investigated using the pulsed laser photolysis-resonance fluorescence (PLP-RF) technique at temperatures between 223 and 363 K. The reactions studied were O(P-3) + CF3I (1), O(P-3) + CH3I (2), O(P-3) + CH2I2 (3), O(P-3) + C2H5I (4), O(P-3) + 1-C3H7I (5), and O(P-3) + 2-C3H7I (6). The Arrhenius expressions (units of cm(3) molecule(-1) s(-1)) obtained were: k(1)(223-363 K) = (8.73 +/- 1.29) x 10(-12) exp-{216 +/- 38)/T}, k(2)(223-363 K) = (9.88 +/- 1.67) x 10(-12) exp{(183 +/- 50)/T}, k(3) (256-363 K) = (7.36 +/- 0.31) x 10(-11) cm(3) molecule(-1) s(-1), k(4)(223-363 K) = (1.58 +/- 0.22) x 10(-11) exp{(239 +/- 39)/T} k(5)(223-363 K) = (1.10 +/- 0.17) x 10(-11) exp{(367 +/- 42)/T}, and k(6)(223-363 K) = (1.84 +/- 0.31) x 10(-11) exp{(296 +/- 46)/T}. With the exception of k(1) and k(3), all the other rate coefficients display a negative temperature dependence, which highlights the importance of association complex formation in reactions of O(P-3) + RI.