Matrix reactions of oxygen atoms with H₂S molecules

Ultraviolet and laser photolysis of dilute argon matrix samples containing O₃ and H₂S molecules at 8°K produced new infrared absorptions at 3425.0, 1177.0, 763.0, and 444.8 cm^-1 which were assigned to the previously unobserved HSOH intermediate species, hydrogen thioperoxide. The HSOH molecule is believed to be formed by the following reaction in the argon matrix cage; {O+H₂S→[H₂S=O] →HSO+H→HSOH}_cage. Extensive ¹⁸O and deuterium isotopic studies had shown this species to contain one oxygen atom and two nonequivalent hydrogen atoms, while the observation of the S-O stretching vibration at 763.0 cm^-1 had confirmed the presence of a sulfur-oxygen single bond. The intense blue-violet chemiluminescence which appeared when the photolyzed matrix samples were warmed to 20°K was subsequently identified as SO₂ phosphorescence (³B₁→ ¹A₁). Fluorescence from ¹B₁→ ¹A₁ was not observed.