Studies on hydrogen–oxygen systems in the electrical discharge. IV. Spectroscopic identification of the matrix-stabilized intermediates, H2O3 and H2O4

Abstract

The infrared absorption of the products from electrically dissociated H2O or D2O vapor and other hydrogen–oxygen systems trapped at liquid nitrogen temperature was measured between 4000 and 300 cm−1. Four new absorption bands were found in the deuterated systems at 857, 820, 760, and about 440 cm−1. By isotopic substitution of 18O the frequencies are shifted to 806, 775, 717, and ~420 cm−1 as expected for O—O vibrations. In the hydrogen systems this region is obscured by the strong libration bands of H2O and H2O2 molecules. Temperature and composition effects show that more than one new species is involved. Accordingly the new spectra are assigned to the often postulated polyoxides, H2O3 and H2O4, stabilized in the water–peroxide matrix. The more abundant, and also more stable, H2O3 has a half-life of some 5 h at −65 °C.The observed frequencies are consistent with zigzag chain structures linked by single covalent bonds as in hydrogen polysulfides. Relative concentrations of the polyoxides are estimated at 5 to 10 mole% depending on the composition of the starting material. Possible mechanisms of formation and decomposition are discussed.