Tetramethylethylenediamine

Tetramethylethylenediamine
Names
	Other names N,N,N′,N′-Tetramethylethane-1,2-diamine[1]
Identifiers
CAS Number	110-18-9 ;
3D model (JSmol)	Interactive image;
Abbreviations	TMEDA, TEMED
Beilstein Reference	1732991
ChEBI	CHEBI:32850 ;
ChemSpider	7746 ;
ECHA InfoCard	100.003.405
EC Number	203-744-6;
Gmelin Reference	2707
MeSH	N,N,N',N'-tetramethylethylenediamine
PubChem CID	8037;
RTECS number	KV7175000;
UNII	K90JUB7941 ;
UN number	2372
CompTox Dashboard (EPA)	DTXSID5026122 ;
	InChI InChI=1S/C6H16N2/c1-7(2)5-6-8(3)4/h5-6H2,1-4H3 Key: KWYHDKDOAIKMQN-UHFFFAOYSA-N ;
	SMILES CN(C)CCN(C)C;
Properties
Chemical formula	C6H16N2
Molar mass	116.208 g·mol−1
Appearance	Colorless liquid
Odor	Fishy, ammoniacal
Density	0.7765 g mL−1 (at 20 °C)
Melting point	−58.6 °C; −73.6 °F; 214.5 K
Boiling point	121.1 °C; 249.9 °F; 394.2 K
Solubility in water	Miscible
Acidity (pKa)	8.97
Basicity (pKb)	5.85
Refractive index (nD)	1.4179
Hazards
Safety data sheet	See: data page
GHS pictograms
GHS Signal word	Danger
GHS hazard statements	H225, H302, H314, H332
GHS precautionary statements	P210, P280, P305+351+338, P310
NFPA 704 (fire diamond)	4 2 1
Flash point	20 °C (68 °F; 293 K)
Explosive limits	0.98–9.08%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	5.39 g kg−1 (dermal, rabbit); 268 mg kg−1 (oral, rat); [2]
Related compounds
Related amines	Triethylenetetramine
Related compounds	Tetraacetylethylenediamine; Ethylenediaminetetraacetic acid; Ethambutol;
Supplementary data page
Structure and; properties	Refractive index (n),; Dielectric constant (εr), etc.
Thermodynamic; data	Phase behaviour; solid–liquid–gas
Spectral data	UV, IR, NMR, MS
	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

Tetramethylethylenediamine (TMEDA or TEMED) is a chemical compound with the formula (CH₃)₂NCH₂CH₂N(CH₃)₂. This species is derived from ethylenediamine by replacement of the four amine hydrogens with four methyl groups. It is a colorless liquid, although old samples often appear yellow. Its odor is remarkably similar to that of rotting fish.[3]

As a reagent in organic and inorganic synthesis

TMEDA is widely employed as a ligand for metal ions. It forms stable complexes with many metal halides, e.g. zinc chloride and copper(I) iodide, giving complexes that are soluble in organic solvents. In such complexes, TMEDA serves as a bidentate ligand.

TMEDA has an affinity for lithium ions.[3] When mixed with n-butyllithium, TMEDA's nitrogen atoms coordinate to the lithium, forming a cluster of higher reactivity than the tetramer or hexamer that n-butyllithium normally adopts. BuLi/TMEDA is able to metallate or even doubly metallate many substrates including benzene, furan, thiophene, N-alkylpyrroles, and ferrocene.[3] Many anionic organometallic complexes have been isolated as their [Li(tmeda)₂]⁺ complexes.[4] In such complexes [Li(tmeda)₂]⁺ behaves like a quaternary ammonium salt, such as [NEt₄]⁺.

TMEDA adduct of lithium bis(trimethylsilyl)amide Notice that the diamine is a bidentate ligand.[5]

It is also worth noting that s-BuLi/TMEDA is also a useful combination in organic synthesis. Utilization of this is useful in cases where the n-butyl anion is able to add into the starting material due to its weak nucleophilic nature. TMEDA is still capable of forming a metal complex with Li in this case as mentioned above.

Other uses

TEMED is used with ammonium persulfate to catalyze the polymerization of acrylamide when making polyacrylamide gels, used in gel electrophoresis, for the separation of proteins or nucleic acids. Although the amounts used in this technique may vary from method to method, 0.1–0.2% v/v TEMED is a "traditional" range. TEMED can also be a component of hypergolic propellants.

References

"N,N,N′,N′-tetramethylethylenediamine – Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Retrieved 30 June 2012.
"MSDS" (PDF).
Haynes, R. K.; Vonwiller, S. C.; Luderer, M. R. (2006). "N,N,N′,N′-Tetramethylethylenediamine". In Paquette, L. (ed.). N,N,N′,N′-Tetramethylethylenediamine. Encyclopedia of Reagents for Organic Synthesis. New York: J. Wiley & Sons. doi:10.1002/047084289X.rt064.pub2. ISBN 0471936235.
Morse, P. M.; Girolami, G. S. (1989). "Are d⁰ ML₆ Complexes Always Octahedral? The X-ray Structure of Trigonal Prismatic [Li(tmed)]₂[ZrMe₆]". Journal of the American Chemical Society. 111 (11): 4114–4116. doi:10.1021/ja00193a061.
Henderson, K. W.; Dorigo, A. E.; Liu, Q.-L.; Williard, P. G. (1997). "Effect of Polydentate Donor Molecules on Lithium Hexamethyldisilazide Aggregation: An X-ray Crystallographic and a Combination Semiempirical PM3/Single Point ab Initio Theoretical Study". J. Am. Chem. Soc. 119: 11855. doi:10.1021/ja971920t.

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[1] "N,N,N′,N′-tetramethylethylenediamine – Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Retrieved 30 June 2012.

[2] "MSDS" (PDF).

[EROS-3] Haynes, R. K.; Vonwiller, S. C.; Luderer, M. R. (2006). "N,N,N′,N′-Tetramethylethylenediamine". In Paquette, L. (ed.). N,N,N′,N′-Tetramethylethylenediamine. Encyclopedia of Reagents for Organic Synthesis. New York: J. Wiley & Sons. doi:10.1002/047084289X.rt064.pub2. ISBN 0471936235.

[4] Morse, P. M.; Girolami, G. S. (1989). "Are d⁰ ML₆ Complexes Always Octahedral? The X-ray Structure of Trigonal Prismatic [Li(tmed)]₂[ZrMe₆]". Journal of the American Chemical Society. 111 (11): 4114–4116. doi:10.1021/ja00193a061.

[5] Henderson, K. W.; Dorigo, A. E.; Liu, Q.-L.; Williard, P. G. (1997). "Effect of Polydentate Donor Molecules on Lithium Hexamethyldisilazide Aggregation: An X-ray Crystallographic and a Combination Semiempirical PM3/Single Point ab Initio Theoretical Study". J. Am. Chem. Soc. 119: 11855. doi:10.1021/ja971920t.