Dimethyl sulfite is a sulfite ester

Sulfite ester

A sulfite ester is a functional group with the structure SO. When substituents R and R' differ, the compound is chiral owing to the stereogenic sulfur centre. They are commonly prepared by the reaction of thionyl chloride with alcohols in the presence of a base such as pyridine:The pesticide...

 with the chemical formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 (CH₃O)₂SO.

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

Structure and conformation

The dimethyl sulfite molecule can adopt several conformation

Conformation

Conformation generally means structural arrangement and may refer to:*Carbohydrate conformation, the three-dimensional shape of a carbohydrate...

s. The most stable is the GG conformer. Each C–O bond is gauche

Alkane stereochemistry

Alkane stereochemistry concerns the stereochemistry of alkanes.Alkane conformers are one of the subjects of alkane stereochemistry.-Conformations:...

 to the S=O bond, depicted below.

Preparation

Although formally derived from sulfurous acid

Sulfurous acid

Sulfurous acid is the chemical compound with the formula H2SO3. There is no evidence that sulfurous acid exists in solution, but the molecule has been detected in the gas phase...

, dimethyl sulfite is prepared from thionyl chloride

Thionyl chloride

Thionyl chloride is an inorganic compound with the formula SOCl2. It is a reactive chemical reagent used in chlorination reactions. It is a colorless, distillable liquid at room temperature and pressure that decomposes above 140 °C. Thionyl chloride is sometimes confused with sulfuryl...

 and methanol.

OSCl₂ + 2CH₃OH → OS(OCH₃)₂ + 2HCl

See also

• Methyl methanesulfonate
  Methyl methanesulfonate
  Methyl methanesulfonate is an alkylating agent and a carcinogen. It is also a suspected reproductive toxicant, and may also be a skin/sense organ toxicant. It is used in cancer treatment.-Chemical reactions with DNA:...
  
  , a chemical with the same molecular formula but different arrangement of atoms
• Diethyl sulfite
  Diethyl sulfite
  Diethyl sulfite is an ester of sulfurous acid. Diethyl sulfite inhibits the growth of mold spores during grain storage.Diethyl sulfite is used as an additive in some polymers to prevent oxidation....
  
  , a similar sulfite ester
• Dimethyl sulfoxide
  Dimethyl sulfoxide
  Dimethyl sulfoxide is an organosulfur compound with the formula 2SO. This colorless liquid is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water...
  
  
• Dimethyl sulfate
  Dimethyl sulfate
  Dimethyl sulfate is a chemical compound with formula 2SO2. As the diester of methanol and sulfuric acid, its formula is often written as 2SO4 or even Me2SO4, where CH3 or Me is methyl...
  
  , a sulfate ester