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Tetramethylethylenediamine

Chemical compound

Wikipedia contributorsAdapted for Fathomly · View authors
1 min read
Source updated May 13, 2026
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Tetramethylethylenediamine (TMEDA or TEMED, sometimes TMEN) 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 similar to that of rotting fish.

01As a reagent in 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. 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. Many anionic organometallic complexes have been isolated as their [Li(tmeda)2]+ complexes. In such complexes [Li(tmeda)2]+ behaves like a quaternary ammonium salt, such as [NEt4]+.

sec-Butyllithium/TMEDA is a useful combination in organic synthesis where the n-butyl analogue adds to substrate. TMEDA is still capable of forming a metal complex with Li in this case as mentioned above.

Structure of the TMEDA adduct of LiN(Si(CH3)3)2. Color code: blue = N, lavender = Li, yellow = Si
Structure of the TMEDA adduct of LiN(Si(CH3)3)2. Color code: blue = N, lavender = Li, yellow = Si

02In molecular biology

TEMED is a common reagent in molecular biology laboratories, as a polymerizing agent for polyacrylamide gels in the protein analysis technique SDS-PAGE.

03Other uses

The complexes (TMEDA)Ni(CH3)2 and [(TMEDA)Ni(o-tolyl)Cl] illustrate the use of tmeda to stabilize homogeneous catalysts.

Synthesis of [(TMEDA)Ni(o-tolyl)Cl]
Synthesis of [(TMEDA)Ni(o-tolyl)Cl]
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Sources and credits

This article is adapted from the Wikipedia article “Tetramethylethylenediamine”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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