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

Dimethyl sulfite
Names
Preferred IUPAC name
Dimethyl sulfite
Other names
Dimethyl sulphite
Sulfurous acid, dimethyl ester
DMSO3[1]
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.009.529 Edit this at Wikidata
EC Number
  • 210-481-0
UNII
  • InChI=1S/C2H6O3S/c1-4-6(3)5-2/h1-2H3 checkY
    Key: BDUPRNVPXOHWIL-UHFFFAOYSA-N checkY
  • InChI=1/C2H6O3S/c1-4-6(3)5-2/h1-2H3
    Key: BDUPRNVPXOHWIL-UHFFFAOYAF
  • COS(=O)OC
  • O=S(OC)OC
Properties
C2H6O3S
Molar mass 110.13 g·mol−1
Appearance Clear liquid
Density 1.29 g/cm3
Boiling point 126 °C (259 °F; 399 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Dimethyl sulfite is used as an additive in some polymers to prevent oxidation.[2] It is also a potentially useful high energy battery electrolyte solvent.[3]

Structure and conformation

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The dimethyl sulfite molecule can adopt several conformations. The most stable is the GG conformer.[1] Each C–O bond is gauche to the S=O bond, depicted below.

 

Preparation

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Dimethyl sulfite is prepared from a 1:2 ratio of thionyl chloride and methanol.[4] The reaction can be catalyzed by tertiary amine bases and likely proceeds via the chlorosulfinate (MeOS(O)Cl),[5] 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.

SOCl2 + 2 CH3OH → (CH3O)2SO + 2 HCl

See also

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References

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  1. ^ a b Borba, A.; Gómez-Zavaglia, A.; Simões, P. N. N. L.; Fausto, R. (2005). "Matrix Isolation FTIR Spectroscopic and Theoretical Study of Dimethyl Sulfite" (PDF). J. Phys. Chem. A. 109 (16): 3578–3586. Bibcode:2005JPCA..109.3578B. doi:10.1021/jp050020t. hdl:10316/12879. PMID 16839024.
  2. ^ Guenther, A.; Koenig, T.; Habicher, W. D.; Schwetlick, K. (1997). "Antioxidant action of organic sulfites. I. Esters of sulfurous acid as secondary antioxidants". Polymer Degradation and Stability. 55 (2): 209–216. doi:10.1016/S0141-3910(96)00150-4.
  3. ^ N. P. Yao; E. D'Orsay; D. N. Bennion (1968). "Behavior of Dimethyl Sulfite as a Potential Nonaqueous Battery Solvent". J. Electrochem. Soc. 115 (10): 999–1003. Bibcode:1968JElS..115..999Y. doi:10.1149/1.2410917.
  4. ^ Voss, Walter; Blanke, Erich (1931). ".Über die Ester der schwefligen Säure (Esters of sulfurous acid)". Justus Liebigs Annalen der Chemie. 485: 258–83. doi:10.1002/jlac.19314850116.
  5. ^ van Woerden, H. F. (December 1963). "Organic Sulfites". Chemical Reviews. 63 (6): 557–571. doi:10.1021/cr60226a001.
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