Sulfonium compounds

Structure of a sulfonium compound (the counterion - an anion - is not shown).

Sulfonium compounds are a group of organic-chemical compounds that contain a positively charged sulfur atom with three substituents. Their general structural formula is R ¹ R ² R ³ S ⁺ , where R ¹ , R ² and R ^{3 are} alkyl or aryl radicals. Their structure is pyramidal.

presentation

Sulfonium salts can be obtained from thioethers by alkylation , e.g. B. with haloalkanes in non-polar solvents and isolate in substance. One example is the reaction of dimethyl sulfide with bromomethane to produce trimethyl sulfonium bromide:

${\displaystyle \mathrm {CH_{3}-S-CH_{3}+CH_{3}Br\longrightarrow (CH_{3})_{3}S^{+}+Br^{-}} }$

properties

Sulfonium salts are mostly crystalline solids that are stable in the absence of water. They are strong alkylating agents.

S-adenosyl methionine

Occurrence

In nature they usually only occur as unstable intermediate stages. A biochemically relevant example is the methyl group transfer agent S-adenosylmethionine .

Individual evidence

1. ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 973.
2. ^ Albert Gossauer: Structure and reactivity of biomolecules , Verlag Helvetica Chimica Acta, Zurich, 2006, p. 228, ISBN 978-3-906390-29-1 .