STRUCTURES, RELATIVE STABILITIES, AND SPECTRA OF ISOMERS OF HCLO2

Ab initio molecular orbital calculations have been carried out to determine the relative stabilities, and the spectroscopy of isomers of HClO2. Two straight-chain isomers, HOOCl and HOClO, and one branched species, HClO2, have been identified as energy minima on the HClO2 potential energy surface. The highest level of calculation performed (CCSD(T)/ANO4) suggests that HOOCl is the lowest energy form. The branched structure is 51.0 kcal mol(-1) higher in energy. The HOClO is 8.3 kcal mol(-1) higher in energy compared to the lowest energy structure. Intense infrared absorptions for HOOCl are calculated at 1399 and 392 cm(-1), at 1186 and 249 cm(-1) for HOClO, and 2168 and 1009 cm(-1) for HClO2. The heat of formation of HOOCl calculated using perturbation theory is similar to that determined using the CCSD(T) level of theory.