Chemiluminescence from the reactions of ozone with sulphur compounds

Abstract

Emissions from excited SO2 in its singlet state (1B1, and/or 1A2) and triplet state (3B1) have been observed in gas-phase chemiluminescent reactions of ozone with a number of sulphur compounds. The compounds studied are carbon disulphide, thiophene, diallyl sulphide, diallyl disulphide, dimethyl sulphide, dimethyl disulphide, and thiophenol. The reaction pathways responsible for the formation of excited molecules are discussed. The remarkable similarity between the emission spectra of the reactions and the chemiluminescence from the SO + O3 reaction confirms that SO is a precursor for the observed chemiluminescence. Disulphides are found to be more chemiluminescent than monosulphides. The absence of chemiluminescence from HCHO* in the reactions of ozone with allyl sulphide and disulphide indicates that the attack of ozone molecule is on the C—S bond in organic sulphides.