Kinetics of the reaction of OH with I2

A steady-state system involving the photolysis of HONO as a source of OH radicals was used to obtain a rate constant for the OH + I2 reaction at 1 atm and 294 K. The value obtained, k=(2.1 ± 1.0)× 10–10 cm3 molecule–1 s–1(relative to the rate constant for OH + C2H4, 8.0 × 10–12 cm3 molecule–1 s–1), was determined from the suppression of [OH] at steady state in the presence of I2 at various concentrations. This reaction probably produces gaseous hypoiodous acid, which was unstable under the experimental conditions employed, resulting in regeneration of I2.