A theoretical study of the reaction of hypochlorous acid with the bromite ion Original Research Article

The structures, vibrational spectra, and relative energetics of possible HClBrO−3 isomers and the HOClOBrO−→HOBrOClO− isomerization transition state existing during the reaction between hypochlorous acid (HOCl) and bromite ions (OBrO−) have been examined by using the Beckeʹs non-local three-parameter exchange with the Lee–Yang–Parr correlation density functional method, in conjunction with two different basis sets. The HOBrOClO− structural form is found to be the most stable among the isomers. The energy required for the formation of HOBrOClO− from the HOCl+OBrO− reaction is 25.2 kcal mol−1, while the energy required for the dissociation of HOBrOClO− to HOBr+OClO− is 22.6 kcal mol−1. The barrier for the isomerization of HOClOBrO− to HOBrOClO− is sufficiently high (30.0 kcal mol−1) to not allow the interconversion between the isomeric forms.