THE POSSIBLE ROLE OF CLO3 ISOMERS IN RELATION TO STRATOSPHERIC OZONE

After considering all possible connectivities for structural isomers of molecular formula ClO3 on the doublet ROHF/6-31G(d) potential energy surface, four minimum energy structures were identified and studied further at some or all of the ROHF, UHF, CIS, UMP2, RMP2, and QCISD(T) levels of theory using various basis sets ranging in quality from 6-31G(d) to 6-311+G(3df). Among the four ClO3 isomers (and alternative electronic states for two of them), only the ground state (2A1) C3v structure was found to be stable at all correlated levels of theory. In particular, the isomers with connectivities ClOOO and OClOO are found to be unstable at the RMP2 and QCISD(T) levels of theory (6-31G(d) basis set). The implications of these results to the chemistry of stratospheric ozone depletion are discussed. In addition, predictions of a variety of physical properties of C3v ClO3 (2A1) were made, including vibrational spectra and thermochemical tabulations based on G2 energy data.