Tetramethylammonium chloride

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Tetramethylammonium chloride
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Names
IUPAC name
Tetramethylazanium chloride
Other names
Tetramethylammonium chloride
Identifiers
75-57-0 YesY
ChemSpider 6139 N
Jmol 3D model Interactive image
PubChem 6379
Properties
C4H12NCl
Molar mass 109.60 g/mol
Appearance White crystals
Density 1.17 g/cm3
Melting point 425 °C (797 °F; 698 K) (decomposes)
Soluble
Hazards
Safety data sheet 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).
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Infobox references

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,[1] being used 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.

Preparation and laboratory uses[edit]

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.[3] The overall reaction is:

NH4+Cl + 2 (CH3O)2CO → N(CH3)4+Cl + 2 H2O + 2 CO2

Although it can be induced to serve as a methylation reagent,[4] it is typically employed as a source of the inert counter cation Me4N+. Similarly it serves as a lipophilic precipitating agent.[5]

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.[6]

Toxicity[edit]

LD50 = 25 mg/kg (mouse, i.p.); 40 mg/kg (mouse, s.c.); 50 mg/kg (rat, p.o.). Very toxic to aquatic organisms.[7]

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

See also[edit]

References[edit]

  1. ^ a b http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+7987
  2. ^ http://fracfocus.org/chemical-use/what-chemicals-are-used
  3. ^ 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. 
  4. ^ 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. 
  5. ^ W. J. Middleton and D. W. Wiley (1973). "tetramethylammonium 1-Propene-1,1,2,3,3-pentacarbonitrile". Org. Synth. doi:10.15227/orgsyn.041.0099. ; Coll. Vol., 5, p. 1013 
  6. ^ Chevet E. et al (1995). "Low concentrations of tetramethylammonium chloride increase yield and specificity of PCR". Nucleic Acids Research 23 (16) 3343–344.
  7. ^ http://datasheets.scbt.com/sc-251199.pdf