Near-infrared-light-induced reaction of singlet sulfur monoxide with allene and dimethylacetylene in a rare gas matrix: infrared spectra of two novel episulfoxides

Abstract

SO{center dot}allene and SO{center dot}dimethylacetylene pairs were prepared in solid Ar at 12 K in order to explore near-infrared-light-induced chemistry of SO(a{sup 1}{Delta}) (T{sub 00} = 5860 cm{sup {minus}1}) and SO(b{sup 1}{Sigma}{sup +}) (T{sub 00} = 10470 cm{sup {minus}1}). Sulfur monoxide was generated by pyrolysis of ethylene episulfoxide in the matrix gas deposition line. Fundamental absorptions of SO(X{sup 3}{Sigma}{sup {minus}}) were measured at 1138.7 cm{sup {minus}1} (Ar), 1134.8 cm{sup {minus}1} (Kr), and 1129.5 cm{sup {minus}1} (Xe). Selective excitation of SO({sup 1}{Delta}) and SO({sup 1}{Sigma}{sup +}) vibronic levels with CW dye laser or filtered tungsten source light led to chemical reaction, the first ever observed of singlet SO. Product analysis by FT-infrared spectroscopy revealed two novel three-membered ring molecules, allene episulfoxide and dimethylacetylene episulfoxide. The SO {sup 1}{Sigma}{sup +}, 1 {l arrow} {sup 3}{Sigma}{sup {minus}}, O vibronic transition was recorded by laser reaction excitation spectroscopy, and an absorption peak was found at 11 420 cm{sup {minus}1} (Ar).