PROTON AFFINITY AND ACIDITY OF HYPOHALOUS ACIDS - A DENSITY-FUNCTIONAL STUDY

The acidities and proton affinities of hypohalous acids HOX and also h ydrohalic acids HX for X = F, Cl, Br, and I are calculated through the Kohn-Sham version of spin-polarized density functional theory with se veral available local as well as nonlocal gradient-corrected exchange- correlation functionals. The calculated values are observed to be in g ood agreement with the available reported results. Unlike the proton a ffinity or acidity values, the calculated gross electron populations a t the atomic sites are not monotonic on going from HOF to HOI and thus cannot explain the calculated proton affinity or acidity trend. Howev er, the trends in acidity as well. as proton affinity are rationalized , in general, in terms of the calculated values of atomic Fukui reacti vity indices.