A pulse radiolysis study of the reaction of OH with I2 and the decay of I2−

The rate constant for the reaction of the hydroxyl radical with iodine was estimated to be (9.5 ± 1.0) × 10 9  dm 3  mol −1  s −1 at 20 °C from fitting the time dependence of the decrease in the absorption of iodine at 460 nm. A number of rate constants associated with the decay of I 2 − that were required for this fitting process were also determined. They were the reaction of I 2 − with I 2 − (2k = (4.6 ± 1.6) × 10 9  dm 3  mol −1  s −1 ) at an ionic strength of 1.2 × 10 −2  mol dm −3 ; I 2 − with I (k = (4.6 ± 1.6) × 10 9  dm 3  mol −1  s −1 ); and I with I (2k = (3.0 ± 1.0) × 10 10  dm 3 mol −1  s −1 ).