Sulfonium

Sulfonium

A sulfonium ion, also known as sulphonium ion and sulfanium ion, is a positively charged sulfur ion carrying three alkyl groups as substituents (S+R3). Ionic compounds consisting of a positively charged sulfonium cation and a negatively charged anion are called sulfonium salts.

Sulfonium compounds can be synthesized from the reaction of dialkylsulfides with alkyl halides:

: CH3-S-CH3 + CH3-I → (CH3)3S+ I− (trimethylsulfonium iodide)

In the above reaction, the alkylation of a sulfide, the sulfur atom has two lone electron pairs. Using those lone pairs, the sulfide acts as a nucleophile, and attacks the carbon of iodomethane. At the same time, as part of a concerted nucleophilic substitution mechanism (SN2), the iodide leaving group comes off; this leaves a positively charged trimethylsulfonium ion. This cation is attracted to the negatively charged iodide, so the two form an ionic bond, giving trimethylsulfonium iodide. [Dan Rather]

See also

*Sulfide R-S-R
*Sulfate R-SO4-R
*Sulfite R-SO3-R
*Sulfonate R-SO3−
*Onium compounds

References

External links

* [http://www.iupac.org/goldbook/S06121.pdf IUPAC definition] (short pdf)


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Look at other dictionaries:

  • sulfonium — ● sulfonium nom masculin Nom générique des cations de formule générale RR′SR″. (Les sels de sulfonium ont un rôle biologique important.) …   Encyclopédie Universelle

  • sulfonium — [sul fō′nē əm] n. [ModL: see SULFO & ONIUM] a monovalent radical containing three alkyl radicals and one atom of sulfur, as the triethyl sulfonium radical (C2H5) 3S …   English World dictionary

  • sulfonium — sulfonis statusas T sritis chemija apibrėžtis Katijonas. formulė H₃S⁺ atitikmenys: angl. sulfonium rus. сульфоний …   Chemijos terminų aiškinamasis žodynas

  • sulfonium — ˌsəlˈfōnēəm noun ( s) Etymology: New Latin, from sulf + onium : a univalent cation H3S+ or radical H3S analogous to oxonium with sulfur in place of oxygen and known especially in the form of organic derivatives (as triethyl sulfonium iodide) made …   Useful english dictionary

  • sulfonium — noun Etymology: New Latin, from sulf + onium Date: 1885 a monovalent group or cation SH3 or derivative SR3 …   New Collegiate Dictionary

  • Sulfonium — Sulfoniumverbindungen sind eine Stoffgruppe organisch chemischer Verbindungen, die ein positiv geladenes Schwefelatom mit drei Substituenten enthalten. Ihre allgemeine Strukturformel ist R S+R*R**, wobei R, R* und R** kohlenstoffhaltige Reste… …   Deutsch Wikipedia

  • sulfonium — /sul foh nee euhm/, n. Chem. the positively charged group H3S+, its salts, or their substitute products. [1890 95; SULF(UR) + (AMM)ONIUM] * * * …   Universalium

  • sulfonium — noun the univalent HS cation, derived from sulfane …   Wiktionary

  • Sulfonium — Sul|fo|ni|um [↑ Sulf u. ↑ onium], das; s: Bez. für das Kation [SH3]+, z. B. Trichlorsulfonium, Methylmethioninsulfoniumchlorid. Als Substituent erhält das S. Ion das Präfix Sulfonio , z. B. Dimethylsulfonio …   Universal-Lexikon

  • sulfonium — sul·fo·ni·um or chiefly Brit sul·pho·ni·um .səl fō nē əm n a monovalent group or cation SH3 or derivative SR3 …   Medical dictionary

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