Atmospheric Reactions in Cryogenic Matrices: Photooxidation of Carbonyl Sulfide (SCO) by Ozone

Abstract

Photooxidation of carbonyl sulfide (SCO) in the presence of ozone has been studied in solid matrices under stratospheric irradiation conditions. The matrix experiments allowed the isolation and identification of SCO ' 0 , 1 : 1 aggregates. Selective photolysis of O3 yielded O('D) atoms and subsequent reaction with SCO resulted in the primary formation of C 0 2 + S. The sulfur atoms generated this way are oxidized to SO? by 02, which has been formed during photofragmentation of 03. In further steps SO2 reacted with diffusing 0 atoms to SO3 and SO4. Experiments with isotopically labeled precursors confirmed the conclusions that the photolysis of "0,. SCO hetero-complexes leads to SlSO2, S1803, and '60C'80 formation.

Reaction Dynamics of O(1D,3P) + OCS Studied with Time-Resolved Fourier Transform Infrared Spectroscopy and Quantum Chemical Calculations

“…In contrast, Jaeger et al performed similar matrix experiments and reported that reaction 5 is major; some S atom product is further oxidized to SO 2 , SO 3 , and SO 4 . 16 Their 18 O 3 / 16 OCS experiments lead to the formation of S 18 O 2 and 16 OC 18 O, supporting the proposed mechanism. To investigate the gaseous reaction of O( 1 D) + OCS, Shortridge and Lin applied resonance absorption of CO laser emission to determine the vibrational population of CO produced upon UV (λ > 215 nm) photolysis of mixtures of O 3 /OCS/SF 6 ; CO (V e 9) with vibrational temperature of 3300 K, corresponding to 4% of the available reaction energy, was reported.…”

Efficient Synthesis of Episulfones and of SO2 with Any Variation of Oxygen Isotopes Using HOF·CH3CN

“…Syntheses to this end had been performed in the past for studying many natural and other phenomena associated with SO 2 . Such molecules were obtained by burning sulfur in the environment of expensive 18 O 2 18 (made from H 2 18 O), difficult to control mixtures of 16 O 2 and 18 O 2 , or with the hard to get 18 O 3 . The present reaction offers a direct way for making S 18 O 2 , S 16 O 18 O, and other variations simply by heating slightly the thermally unstable episulfones which decompose to SO 2 and the corresponding olefin.…”

“…17 Such molecules were obtained by burning sulfur in the environment of expensive 18 O 2 18 (made from H 2 18 O), difficult to control mixtures of 16 O 2 and 18 O 2 , 19 or with the hard to get 18 O 3 . 20 The present reaction offers a direct way for making S 18 O 2 , S 16 In conclusion, HOF‚CH 3 CN made readily from F 2 is a powerful and versatile tool in general chemistry whenever (15) Fialkov, A. B.; Amirav, A. J.…”

Direct determination of the rate coefficient for the reaction of O(1D) with OCS

“…There has been only one report on the rate coefficient indirectly determined using a reference reaction O( 1 D) + O 2 ? O ( 3 P) + O 2 [12], although a few studies on the reaction products have been reported [6,[13][14][15]. Chiang et al [15] have recently observed infrared emission from CO and CO 2 in the O 3 /OCS/Ar/248 nm system using time-resolved Fourier-transform infrared spectroscopy, giving evidence for direct generation of CO and CO 2 in the reaction O( 1 D) + OCS.…”