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

Abstract

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 skewedstraight 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.

Computational Studies of (HIO3) Isomers and the HO2 + IO Reaction Pathways

“…It is clear from the similar stabilities of HOOOI and HOOIO at the CCSD(T) level that both structures are equally probable on energetic grounds, to be formed as nascent complexes in reaction 1. As already said, this is an interesting difference from the HO 2 + ClO, BrO reactions, where the HOOClO and HOOBrO adducts are found to be ∼15 kcal mol -1 higher than HOOOCl and HOOOBr at the CCSD(T) level [14][15][16] and their formation is thus much less probable. Once activated HOOIO and HOOOI are formed as HO 2 and IO approach each other, they may subsequently follow several production pathways.…”

“…This tendency is entirely different from what has been observed in the (HClO 3 ) and (HBrO 3 ) families. [14][15][16] The corresponding HOOOCl and HOOOBr adducts have been found to be substantially more stable than HOOClO and HOOBrO, and they are preferably formed as intermediates in the HO 2 + XO reactions.…”

Kinetics of the HO2+BrO reaction over the temperature range 233–348 K

“…In the system involving Cl, Francisco and Sander calculated enthalpies of formation for several isomers using both HClO 3 isodesmic reactions at the QCISD(T)/6-311G(2df,2p) level and G1/G2 theory. 25 Values of (in kcal mol~1) were deter- …”

“…In the system involving Cl, Francisco and Sander calculated enthalpies of formation for several isomers using both HClO 3 isodesmic reactions at the QCISD(T)/6-311G(2df,2p) level and G1/G2 theory. 25 where denotes a collisionally stabilized adduct. HO 2 É BrO Several previous studies including the present work found that reaction (3a) was an important, if not the predominant, reaction channel but were not able to establish that the branching ratio for reaction (3a) was unity.8,10 On the other hand, there is positive evidence that the branching ratio for reaction (3b) is quite small.…”

Removal of Elemental Mercury from a Gas Stream Facilitated by a Non-Thermal Plasma Device

“…Ab initio methods have been utilized to investigate the gas phase properties of potentially important reactants such as O + OClO (Colussi et al, 1992) and HClO 3 (Francisco and Sander, 1996). The equilibrium structures HOClO 3 and HO 4 Cl have also been examined (Francisco, 1995).…”