Dimethyl sulfite explained

Dimethyl sulfite is a sulfite ester with the chemical formula (CH₃O)₂SO.

Dimethyl sulfite is used as an additive in some polymers to prevent oxidation.^[1] It is also a potentially useful high energy battery electrolyte solvent.^[2]

Structure and conformation

The dimethyl sulfite molecule can adopt several conformations. The most stable is the GG conformer. Each C–O bond is gauche to the S=O bond, depicted below.

Preparation

Dimethyl sulfite is prepared from a 1:2 ratio of thionyl chloride and methanol.^[3] The reaction can be catalyzed by tertiary amine bases and likely proceeds via the chlorosulfinate (MeOS(O)Cl),^[4] this intermediate will exist only fleetingly in the presence of methanol and as such its decomposition to methyl chloride and sulfur dioxide (via the slower SNi mechanism) is not observed to any great extent.

See also

• Methyl methanesulfonate, a chemical with the same molecular formula but different arrangement of atoms
• Diethyl sulfite, a similar sulfite ester
• Dimethyl sulfoxide
• Dimethyl sulfate, a sulfate ester

External links

• WebBook page for C2H6SO3

Notes and References

1. Antioxidant action of organic sulfites. I. Esters of sulfurous acid as secondary antioxidants. Guenther, A. . Koenig, T. . Habicher, W. D. . Schwetlick, K. . Polymer Degradation and Stability. 1997. 55. 2. 209–216. 10.1016/S0141-3910(96)00150-4.
2. Behavior of Dimethyl Sulfite as a Potential Nonaqueous Battery Solvent. J. Electrochem. Soc.. 115. 10. 999–1003. 1968. N. P. Yao . E. D'Orsay . D. N. Bennion . 10.1149/1.2410917. 1968JElS..115..999Y.
3. .Über die Ester der schwefligen Säure (Esters of sulfurous acid). Voss, Walter. Blanke, Erich. Justus Liebigs Annalen der Chemie. 1931. 485. 258–83. 10.1002/jlac.19314850116.
4. van Woerden. H. F.. Organic Sulfites.. Chemical Reviews. December 1963. 63. 6. 557–571. 10.1021/cr60226a001.