Thermal rate constants over thirty orders of magnitude for the I+H2 reaction

I-atom atomic resonance absorption spectrometry has been used to measure thermal rate constants for the I + H-2 --> HI + H reaction between 1755 and 2605 K in reflected shock waves. Measured rate constants can then be expressed by k(1) = (3.92 +/- 1.15) X 10(-9) exp(-21 398 +/- 658 K/T) cm(3) molecule(-1) s(-1). Combining these results with earlier values, the rate behavior over the combined temperature range, 230 K less than or equal to T less than or equal to 2605 K, is: k(1) = (4.52 +/- 0.34) X 10(-10) exp(-17 070 +/- 34 K/T) cm(3) molecule(-1) s(-1). This result holds over similar to 30 orders of magnitude and is discussed in terms of bimolecular rate theory. (C) 2000 Elsevier Science B.V. All rights reserved.