Tetramethylammonium chloride

Tetramethylammonium chloride is one of the simplest quaternary ammonium salts, with 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 hygroscopic colourless solid that is soluble in water and polar organic solvents. Tetramethylammonium chloride is a major industrial chemical, being used widely as a chemical reagent^[1] and also as a low-residue bactericide in such processes as hydrofracking.^[2] 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.

Tetramethylammonium chloride

Tetramethylammonium ion. Blue: nitrogen, black: carbon, white: hydrogen
Names
Preferred IUPAC name N,N,N-Trimethylmethanaminium chloride
Other names Tetramethylammonium chloride Tetramethylazanium chloride
Identifiers
CAS Number	75-57-0 Y
3D model (JSmol)	Interactive image
ChemSpider	6139 N
ECHA InfoCard	100.000.801
PubChem CID	6379
UNII	DCQ9S88703 Y
CompTox Dashboard (EPA)	DTXSID501030186 DTXSID6021749, DTXSID501030186
InChI InChI=1S/C4H12N.ClH/c1-5(2,3)4;/h1-4H3;1H/q+1;/p-1 N Key: OKIZCWYLBDKLSU-UHFFFAOYSA-M N InChI=1/C4H12N.ClH/c1-5(2,3)4;/h1-4H3;1H/q+1;/p-1 Key: OKIZCWYLBDKLSU-REWHXWOFAY
SMILES C[N+](C)(C)C.[Cl-]
Properties
Chemical formula	C4H12NCl
Molar mass	109.60 g/mol
Appearance	White crystals
Density	1.17 g/cm3
Melting point	425 °C (797 °F; 698 K) (decomposes)
Solubility	Soluble in water and methanol. Slightly soluble in ethanol. Insoluble in ether, benzene, chloroform.
Hazards
Safety data sheet (SDS)	External MSDS
Related compounds
Other anions	tetramethylammonium hydroxide
Other cations	tetraethylammonium chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation and laboratory uses

Tetramethylammonium chloride is efficiently produced by the reaction of trimethylamine and methyl chloride.^[3]

N(CH₃)₃ + CH₃Cl → N(CH₃)₄⁺Cl⁻

It is produced by the alkylation of ammonium chloride with dimethyl carbonate in the presence of an ionic liquid catalyst.^[4]

Except under extraordinary conditions,^[5] it is typically employed as a source of the inert counter cation Me₄N⁺. Similarly, it serves as a lipophilic precipitating agent.^[6]

In low concentrations, it is used in polymerase chain reactions to increase yields and specificity. It has been shown to enhance yields 5–10 fold at 60mM by stabilizing the AT base pairs.^[7]

Toxicity

LD₅₀ = 25 mg/kg (mouse, i.p.); 40 mg/kg (mouse, s.c.); 50 mg/kg (rat, p.o.). Very toxic to aquatic organisms.^[8]

Diverse data on human exposure, environmental toxicology and environmentally-related chemistry is available through the NIH Toxnet database.^[1]

See also

• Quaternary ammonium cation
• Tetraethylammonium chloride
• Tetramethylammonium hydroxide
• Tetramethylammonium

References

1. "Tetramethylammonium chloride - National Library of Medicine HSDB Database". Archived from the original on 2015-12-22. Retrieved 2012-09-24.
2. "What Chemicals Are Used | FracFocus Chemical Disclosure Registry". Archived from the original on 2013-08-14. Retrieved 2012-10-30.
3. Van Gysel, August B.; Musin, Willy (2000). "Methylamines". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_535. ISBN 978-3527306732.
4. Zheng, Z.; Wang, Jie; Wu, Ting Hua; Zhou, Xiao Ping; et al. (2007). "Alkylation of Ammonium Salts Catalyzed by Imidazolium-Based Ionic Liquid Catalysts". Advanced Synthesis & Catalysis. 349 (7): 1095–1101. doi:10.1002/adsc.200600451.
5. Nenad, Maraš; Polanc, Slovenko; Kočevar, Marijan (2008). "Microwave-assisted methylation of phenols with tetramethylammonium chloride in the presence of K₂CO₃ or Cs₂CO₃". Tetrahedron. 64 (51): 11618–11624. doi:10.1016/j.tet.2008.10.024.
6. W. J. Middleton and D. W. Wiley (1973). "tetramethylammonium 1-Propene-1,1,2,3,3-pentacarbonitrile". Organic Syntheses. doi:10.15227/orgsyn.041.0099; Collected Volumes, vol. 5, p. 1013.
7. Chevet E. et al. (1995). "Low concentrations of tetramethylammonium chloride increase yield and specificity of PCR". Nucleic Acids Research 23 (16) 3343–344.
8. "Tetramethylammonium chloride" (PDF). Datasheets.scbt.com. Retrieved 14 March 2022.