The rate constant for the reaction O(3P)+D2 at low temperatures.

The rate constant for the reaction of O(3P)+D2 was measured over the temperature range 343 to 446 K using the laser photolysis–resonance fluorescence technique. The results can be fit well with a two-parameter Arrhenius function and are in excellent agreement with the previous measurements of Presser and Gordon and with the recent high temperature measurements of Michael. The data are also in very good agreement with the theoretical calculations of Joseph et al. and of Bowman et al. and demonstrate that tunneling makes a significant contribution to the rate coefficient over the entire range of temperatures studied in this experiment. The Arrhenius behavior of the rate constant supports the conclusions of Robie et al. in their study of the intramolecular isotope effect in O(3P)+HD, where it was found that tunneling plays a major role at low temperatures. [ABSTRACT FROM AUTHOR]