Carbon disulfide hydroxyl radical reaction

The lifetime of carbon disulfide in the atmosphere has been estimated to be 12 days, too short a time to reach the stratosphere. Removal was suggested to occur by a hydroxyl radical reaction, or an oxygen atom reaction but not by dissociation (Khalil and Rasmussen 1984). 

Bonifacic M, Schafer K, Mockel H, Asmus K-D (1975b) Primary steps in the reactions of organic disulfides with hydroxyl radicals in aqueous solution. J Phys Chem 79 1496-1502 Bonifacic M, Armstrong DA, Carmichael I, Asmus K-D (2000a) p-Fragmentation and other reactions involving aminyl radicals from amino acids. J Phys Chem B 104 643-649 Bonifacic M, Hug GL, Schoneich C (2000b) Kinetics of the reactions between sulfide radical cation complexes,[S.. S]+ and [S. N]+, and superoxide or carbon dioxide radical anions. J Phys Chem A 104 1240-1245... 

An example in which formation of a carbon radical is not the initial reaction is provided by the atmospheric reactions of organic sulfides and disulfides. They also provide an example in which rates of reaction with nitrate radicals exceed those with hydroxyl radicals. 2-dimethylthiopropionic acid is produced by algae and by the marsh grass Spartina alternifolia, and may then be metabolized in sediment slurries under anoxic conditions to dimethyl sulfide (Kiene and Taylor 1988), and by aerobic bacteria to methyl sulfide (Taylor and Gilchrist 1991). It should be added that methyl sulfide can be produced by biological methylation of sulfide itself (HS ) (Section 6.11.4). Dimethyl sulfide — and possibly also methyl sulfide — is oxidized in the troposphere to sulfur dioxide and methanesulfonic acids. 

Carbon disulfide reacts with hydroxyl radicals in the troposphere to produce carbonyl sulfide (Cox and Sheppard 1980). The lifetime of carbon disulfide in the troposphere, assuming a reaction rate constant of 4.3 x 10"13 cm3 molecule 1, is 73 days (uncertain) other estimates (assuming different reaction rate constants) range from less than 1 week to more than 10 weeks (Cox and Sheppard 1980 EPA 1978a ... 

Atkinson R, Perry RA, Pitts JN Jr. 1978. Rate constants for the reaction of hydroxyl radicals with carbonyl sulfide, carbon disulfide and dimethyl thioether over the temperature range 299-430 K. Chem Phys Lett 54 14-18. 

Some contradictory results have also been reported, however. For instance, in the decomposition of carbon disulfide (Entezari et al., 1997), frequency has no apparent effect, whereas in reactions such as oxidation higher frequencies may lead to enhanced reaction rates (Entezari and Kruus, 1994). The latter is probably due to the high rate of hydroxyl radical formation at higher frequencies (Petrier et al., 1992 Entezari and Kruus, 1996 Mason et al., 1994). 

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