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) × 10⁹ dm³ 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 I₂⁻ that were required for this fitting process were also determined. They were the reaction of I₂⁻ with I₂⁻ (2k = (4.6 ± 1.6) × 10⁹ dm³ mol⁻¹ s⁻¹) at an ionic strength of 1.2 × 10⁻² mol dm⁻³; I₂⁻ with I (k = (4.6 ± 1.6) × 10⁹ dm³ mol⁻¹ s⁻¹); and I with I (2k = (3.0 ± 1.0) × 10¹⁰ dm³ mol⁻¹ s⁻¹).