[en] The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H₃BO₃ at temperatures up to 150⁰C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO₃^- + 2I^- + 3H⁺, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >10⁴ has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs