Recombination of iodine atoms in sulfur dioxide

The reaction 2I + SO2 → I2 + SO2 has been studied between 293 and 668°K. At 293°K, the recombination rate constant is 2.6 × 1010]2 mole−2 s−1; it attains 1/10 of this value at 668°K. Although the infrared and ultraviolet spectra of SO2, studied previously, suggest the existence of two forms of SO2 in the temperature range in question, the present recombination studies present no further supporting evidence about the existence of the excited form.