STRUCTURES, RELATIVE STABILITIES, AND SPECTRA OF ISOMERS OF HCLO2

Ab initio molecular orbital calculations have been carried out to dete rmine the relative stabilities, and the spectroscopy of isomers of HCl O2. Two straight-chain isomers, HOOCl and HOClO, and one branched spec ies, HClO2, have been identified as energy minima on the HClO2 potenti al energy surface. The highest level of calculation performed (CCSD(T) /ANO4) suggests that HOOCl is the lowest energy form. The branched str ucture is 51.0 kcal mol(-1) higher in energy. The HOClO is 8.3 kcal mo l(-1) higher in energy compared to the lowest energy structure. Intens e 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.