|Jmol-3D images||Image 1|
|Molar mass||109.60 g/mol|
|Melting point||425 °C (797 °F; 698 K) (decomposes)|
|Solubility in water||Soluble|
|Other anions||tetramethylammonium hydroxide|
|Other cations||tetraethylammonium chloride|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Tetramethylammonium chloride is one of the simplest quaternary ammonium salts, bearing only four methyl groups tetrahedrally attached to the central N. The chemical formula (CH3)4N+Cl− is often abbreviated further as Me4N+Cl−. It is a very hygroscopic colourless solid that is soluble in water and polar organic solvents. Tetramethylammonium chloride is a major industrial chemical, being used in such processes as hydrofracking. In the laboratory, it has fewer synthetic chemical applications than quaternary ammonium salts containing longer N-alkyl substituents, which are used extensively as phase-transfer catalysts.
Preparation and laboratory uses
Tetramethylammonium chloride can be synthesized by the alkylation of ammonium chloride with dimethyl carbonate, in the presence of 1-ethyl-3-methyl imidazolium bromide ([EMIM]+Br−) as an ionic liquid catalyst. The overall reaction is:
- NH4+Cl− + 2 (CH3O)2CO → N(CH3)4+Cl− + 2 H2O + 2 CO2
It is used in organic synthesis for methylation and occasionally as a precipitating agent.
In low concentrations, it is used in polymerase chain reactions to increase yield and specificity. It has been shown to enhance yield 5–10 fold at 60mM by stabilizing the AT base pairs.
LD50 = 25 mg/kg (mouse, i.p.); 40 mg/kg (mouse, s.c.); 50 mg/kg (rat, p.o.). Very toxic to aquatic organisms.
- Quaternary ammonium cation
- Tetraethylammonium chloride
- Tetramethylammonium hydroxide
- Zheng, Z. et al.; Wang, Jie; Wu, Ting Hua; Zhou, Xiao Ping (2007). "Alkylation of Ammonium Salts Catalyzed by Imidazolium-Based Ionic Liquid Catalysts". Advanced Synthesis & Catalysis 349 (7): 1095–1101. doi:10.1002/adsc.200600451.
- W. J. Middleton and D. W. Wiley (1973), "tetramethylammonium 1-Propene-1,1,2,3,3-pentacarbonitrile", Org. Synth.; Coll. Vol. 5: 1013
- Chevet E. et al (1995). "Low concentrations of tetramethylammonium chloride increase yield and specificity of PCR". Nucleic Acids Research 23 (16) 3343–344.