Thermal and photochemical exchange of iodine with trifluoro-methyl iodide

Abstract

The thermal and photochemical exchange reactions between I2 and CF3I were investigated in the gas phase between 100 and 180°C. The homogeneous thermal and photochemical reactions are initiated by I atoms and the exchange proceeds by abstraction I+CF3I→CF3+I2(1) followed by CF3+I2→CF3I+I. The rate constant k1 is given by 109.6 exp(– 16000/RT) l. mole–1 sec–1. From the activation energy for (1), D(CF3–I) is 51.5 ± 0.5 kcal mole–1. Rotating sector measurements lead to a value for the apparent second-order rate constant of the I atom recombination, I+I+M →I2+M in the presence of CF3I of 5.1 ± 2.0 × 107 l. mole–1 sec–1 at 100°C.