VIBRATIONAL AND ELECTRONIC-SPECTRA OF CHLORINE DIOXIDE, OCLO, AND CHLORINE SUPEROXIDE, CLOO, ISOLATED IN CRYOGENIC MATRICES

Neon and argon matrix FTIR spectra of chlorine dioxide, OClO, in natural isotopic abundance and enriched in O-18 have been recorded. All fundamentals, and two overtones, as well as two combination bands have been observed for six isotopomers. Anharmonic constants, bond angles, and force constants have been calculated. The neon matrix data are very close to values from gas-phase studies, whereas the argon matrix data show more prominent deviations. Irradiation of matrix-isolated, monomeric OClO with visible light (lambda greater-than-or-equal-to 395 nm) quantitatively converted it to the chlorine superoxide radical, ClOO. The ratio of IR and UV band intensities of both ClO2 isomers was determined. All fundamentals, four overtones, and five combination bands were observed for eight isotopomers of ClOO. The Cl-OO stretching vibration P3 near 200 cm-1 has been observed for the first time, and the band near 390 cm-1, previously assigned to nu3, has been shown to be due to 2nu3. Anharmonic constants, harmonic wavenumbers, and force constants agree well with data from recent ab initio calculations and fit well in the series of related XEO molecules (X = -, F, Cl; E = C, N, O). The description of nu2 and nu3 respectively in terms of internal coordinates is discussed. Photolysis of a small fraction of matrix-isolated OClO van der Waals dimers resulted in ClOClO3, ClOClO2, and ClOClO as byproducts. IR spectroscopic evidence for this dimer was obtained from neon matrix experiments.