Superoxide reaction with sulfur radicals

This latter reaction is similar to the gas-phase reactions between S02" and SO2. Chemical reduction by alkali metals can also be used and work with lithium suggests that the complex 8204 also dimerizes [29]. In non-aqueous solvents, the reaction of sulfur dioxide with superoxide produces the sulfur dioxide radical anion, but with an equilibrium constant of only about =1.1 [30], reaction (16) ... 

W.H. Orme-Johnson and H. Beinert, Formation of the superoxide anion radical during the reaction of reduced iron-sulfur proteins with oxygen. Biochem. Biophys. Res. Commun. 36, 905-911 (1969). 

Recently, sulfinyl and sulfonyl peroxy radical intermediates 6a and 6b have been prepared by the reactions of aryl sulfinyl or sulfonyl chloride with superoxide anion radical, respectively. These peroxy intermediates show strong oxidizing abilities in various oxidations. This chapter will describe the properties and applications of a variety of sulfur and phosphorus peroxy compounds in oxidation reactions. For a more complete picture, readers should consult the original papers cited in the areas that most interest them. 

Sulfur cycling is affected in a variety of ways, including UV photoinhibition of organisms such as bacterioplankton and zooplankton that affect sources and sinks of DMS and UV-initiated CDOM-sensitized photoreactions that oxidize DMS and produce carbonyl sulfide. Metal cycling also interacts in many ways with UVR via direct photoreactions of dissolved complexes and of metal oxides and indirect reactions that are mediated by photochemically-produced ROS. Photoreactions can affect the biological availability of essential trace nutrients such as iron and manganese, transforming the metals from complexes that are not readily assimilated into free metal ions or metal hydroxides that are available. Such photoreactions can enhance the toxicity of metals such as copper and can initiate metal redox reactions that transform non-reactive ROS such as superoxide into potent oxidants such as hydroxyl radicals. 

The mechanism proposed for the uncatalyzed reaction involves electron transfer from the thioether to afford superoxide ion and a sulfur-centered cation radical. The latter reacts with 0 to yield a... 

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