Names | |
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IUPAC name
Trimethylsulfonium
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Systematic IUPAC name
Trimethylsulfanium | |
Other names
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Identifiers | |
3D model (
JSmol)
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ChemSpider | |
PubChem
CID
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UNII | |
CompTox Dashboard (
EPA)
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Properties | |
(CH3)3S+ | |
Molar mass | 77.17 g·mol−1 |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Trimethylsulfonium (systematically named trimethylsulfanium) is an organic cation with the chemical formula ( C H3)3 S+ (also written as C3H9S+).
Several salts of trimethylsulfonium are known. X-ray crystallography reveals that the ion has trigonal pyramidal molecular geometry at sulfur atom, with C-S-C angles near 102° and C-S bond distance of 177 picometers. Unless the counteranion is colored, all trimethylsulfonium salts are white or colorless.
Salt | Formula | Molecular weight (g/mol) | Properties [2] |
---|---|---|---|
Trimethylsulfonium chloride | [(CH3)3S]+Cl− | 112.5 | Colorless crystals, decompose at 100 °C, very soluble in ethanol, very hygroscopic. [3] |
Trimethylsulfonium bromide | [(CH3)3S]+Br− | 157 | Colorless crystals. Decomposes at 172 °C, melts in a sealed tube at 201-201 °C, reacts in neutral aqueous solution.[ clarification needed] [4] |
Trimethylsulfonium iodide | [(CH3)3S]+I− | 204 | Colorless crystals, decomposes at 203-207 °C. [4] [5] crystal structure monoclinic, with these parameters: a = 5.94 μm, b = 8.00 μm, c = 8.92 μm, β = 126°32′ 2 formulas per unit cell,[ clarification needed] density = 1.958 g/cm3 [6] |
Trimethylsulfonium tetrafluoroborate | [(CH3)3S]+[BF4− | 163.97 | melting point = 205-210 °C [7] |
Trimethylsulfonium methylsulfate | [(CH3)3S]+CH3OSO−3 | 188.27 | melting point = 92-94 °C [8] Crystal structure orthorhombic with these parameters: a = 12.6157 μm, b = 8.2419 μm, c = 7.540 μm cell volume 784.0 2 formulas per unit cell[ clarification needed] |
Sulfonium compounds can be synthesised by treating a suitable alkyl halide with a thioether. For example, the reaction of dimethyl sulfide with iodomethane yields trimethylsulfonium iodide:
An extra oxygen atom can bond to the sulfur atom to yield the trimethylsulfoxonium ion [(CH3)3S=O]+, where the sulfur atom is tetravalent and tetracoordinated.
Glyphosate herbicide is often supplied as a trimethylsulfonium salt, referred to as trimesium. [9]
When mixed with aluminium bromide, or aluminium chloride or even hydrogen bromide, trimethylsulfonium bromide forms an ionic liquid, which melts at temperatures below standard conditions. [10]
Names | |
---|---|
IUPAC name
Trimethylsulfonium
| |
Systematic IUPAC name
Trimethylsulfanium | |
Other names
| |
Identifiers | |
3D model (
JSmol)
|
|
ChemSpider | |
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
(CH3)3S+ | |
Molar mass | 77.17 g·mol−1 |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Trimethylsulfonium (systematically named trimethylsulfanium) is an organic cation with the chemical formula ( C H3)3 S+ (also written as C3H9S+).
Several salts of trimethylsulfonium are known. X-ray crystallography reveals that the ion has trigonal pyramidal molecular geometry at sulfur atom, with C-S-C angles near 102° and C-S bond distance of 177 picometers. Unless the counteranion is colored, all trimethylsulfonium salts are white or colorless.
Salt | Formula | Molecular weight (g/mol) | Properties [2] |
---|---|---|---|
Trimethylsulfonium chloride | [(CH3)3S]+Cl− | 112.5 | Colorless crystals, decompose at 100 °C, very soluble in ethanol, very hygroscopic. [3] |
Trimethylsulfonium bromide | [(CH3)3S]+Br− | 157 | Colorless crystals. Decomposes at 172 °C, melts in a sealed tube at 201-201 °C, reacts in neutral aqueous solution.[ clarification needed] [4] |
Trimethylsulfonium iodide | [(CH3)3S]+I− | 204 | Colorless crystals, decomposes at 203-207 °C. [4] [5] crystal structure monoclinic, with these parameters: a = 5.94 μm, b = 8.00 μm, c = 8.92 μm, β = 126°32′ 2 formulas per unit cell,[ clarification needed] density = 1.958 g/cm3 [6] |
Trimethylsulfonium tetrafluoroborate | [(CH3)3S]+[BF4− | 163.97 | melting point = 205-210 °C [7] |
Trimethylsulfonium methylsulfate | [(CH3)3S]+CH3OSO−3 | 188.27 | melting point = 92-94 °C [8] Crystal structure orthorhombic with these parameters: a = 12.6157 μm, b = 8.2419 μm, c = 7.540 μm cell volume 784.0 2 formulas per unit cell[ clarification needed] |
Sulfonium compounds can be synthesised by treating a suitable alkyl halide with a thioether. For example, the reaction of dimethyl sulfide with iodomethane yields trimethylsulfonium iodide:
An extra oxygen atom can bond to the sulfur atom to yield the trimethylsulfoxonium ion [(CH3)3S=O]+, where the sulfur atom is tetravalent and tetracoordinated.
Glyphosate herbicide is often supplied as a trimethylsulfonium salt, referred to as trimesium. [9]
When mixed with aluminium bromide, or aluminium chloride or even hydrogen bromide, trimethylsulfonium bromide forms an ionic liquid, which melts at temperatures below standard conditions. [10]