Structures, Relative Stabilities, and Vibrational Spectra of Isomers of HClO3

Ab initio molecular orbital calculations have been carried out to examine the relative stabilities and the spectroscopy of isomers of HClO 3 . The lowest energy structure is HOClO 2, and its heat of formation at 0 K is calculated to be 4.2 kcal mol -1 as determined from G2 theory. The next lowest energy isomer is a skewed-straight chain HOOOCl. It is 4.9 kcal mol -1 above the lowest energy form. The two higher energy structures are HOOClO and the hypervalent HClO 3 . An examination of the vibrational and electronic spectra reveals spectral features that allow these species to be uniquely distinguished.