Triethylenetetramine, abbreviated TETA and trien, is an organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 with the formula [CH₂NHCH₂CH₂NH₂]₂. This oily liquid is colourless but, like many amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s, assumes a yellowish color due to impurities resulting from air-oxidation. It is soluble in polar solvents and exhibits the reactivity typical for amines. The branched isomer

Isomer

In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...

 N(CH₂CH₂NH₂)₃

Tris(2-aminoethyl)amine

Trisamine is the organic compound with the formula N3. This colourless liquid is soluble in water and is highly basic, consisting of a tertiary amine center and three pendant primary amine groups...

 and the cyclic triamine (CH₂CH₂NH)₃ also comprise commercial samples of TETA.

Production

Triethylenetetramine is prepared by heating ethylenediamine or ethanolamine

Ethanolamine

Ethanolamine, also called 2-aminoethanol or monoethanolamine , is an organic chemical compound that is both a primary amine and a primary alcohol . Like other amines, monoethanolamine acts as a weak base...

/ammonia

Ammonia

Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 mixtures over an oxide catalyst. This process gives a variety of amines, which are separated by distillation and sublimation.

Uses

The reactivity and uses of TETA are similar to those for the related polyamines ethylenediamine and diethylenetriamine. It was primarily used as a crosslinker ("hardener") in epoxy

Epoxy

Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....

 curing.

The hydrochloride salt of triethylenetetramine, referred to as trientine hydrochloride, is a chelating agent, and is used to bind up and remove copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 in the body to treat Wilson's disease

Wilson's disease

Wilson's disease or hepatolenticular degeneration is an autosomal recessive genetic disorder in which copper accumulates in tissues; this manifests as neurological or psychiatric symptoms and liver disease...

, particularly in those who are intolerant to penicillamine

Penicillamine

Penicillamine is a pharmaceutical of the chelator class. It is sold under the trade names of Cuprimine and Depen. The pharmaceutical form is D-penicillamine, as L-penicillamine is toxic...

. Some recommend trientine as first-line treatment, but experience with penicillamine is more extensive.

Coordination chemistry

Triethylenetetramine is a tetradentate ligand

Ligand

In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...

 in coordination chemistry, where it is referred to as trien. Octahedral complexes of the type M(trien)Cl₃ can adopt several diastereomeric structures, most of which are chiral

Chirality (chemistry)

A chiral molecule is a type of molecule that lacks an internal plane of symmetry and thus has a non-superimposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom....

.