View source for Tris(2-aminoethyl)amine

{{chembox
|   Name = Tris(2-aminoethyl)amine  
|   ImageFile = Tris(2-aminoethyl)amine.svg
| ImageSize = 
|   ImageName = 
|   IUPACName = Tris(2-aminoethyl)amine
|   OtherNames =  2,2',2''-Nitrilotriethylamine<br/>2,2',2''-Triaminotriethylamine<br/>TAEA<br/>4-(2-aminoethyl)diethylenetriamine<br/>nitrilotris(ethylamine)<br/> tris(aminoethyl)amine<br/>tris(beta-aminoethyl)amine<br/>Tren 
| Section1 = {{Chembox Identifiers
|   SMILES = 
|   CASNo = 4097-89-6
|   EINECS/ELINCS = 223-857-4
|   RTECS = KH8587082
|   PubChem = 77731
  }}
| Section2 = {{Chembox Properties
|   Formula =  	(NH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>)<sub>3</sub>N
|   MolarMass = 146.236 g/mol
|   Appearance = colourless
|   Density = 0.977 &nbsp;g/cm<sup>3</sup>
|   Solubility = miscible
|   Solvent = <!-- other solvents -->
|   SolubleOther = polar organic solvents
|   MeltingPt = −16 °C
|   BoilingPt = 265 °C
  }}
| Section3 = {{Chembox Structure
|   Coordination = <!-- edge-shared bioctahedron -->
|   CrystalStruct = 
|   Dipole =
  }}
| Section7 = {{Chembox Hazards
|   ExternalMSDS =[https://fscimage.fishersci.com/msds/98548.htm Fisher Scientifc MSDS]
|   MainHazards = Corrosive
|   RPhrases = 22-24-34
|   SPhrases = 26-36/37/39-45
  }}
| Section8 = {{Chembox Related
|   OtherCpds = 
  }}
}}
'''Tris(2-aminoethyl)amine''' is the [[organic compound]] with the [[chemical formula|formula]] N(CH<sub>2</sub>CH<sub>2</sub>NH<sub>2</sub>)<sub>3</sub>. This colourless liquid is soluble in water and is highly basic, consisting of a [[tertiary amine]] center and three pendant [[primary amine]] groups.  Abbreviated "tren," it is the archetypal tripodal ligand of interest in [[coordination chemistry]].

==Coordination chemistry==
Tren is a tripodal, tetradentate chelating ligand that forms stable complexes with transition metals, especially those in the 2+ and 3+ oxidation states. Tren complexes exist with relatively few isomers, reflecting the constrained connectivity of this tetramine. Thus, only a single achiral stereoisomer exists for [Co(tren)X<sub>2</sub>]<sup>+</sup>, where X is halide or pseudohalide.<ref>Donald A. House “Ammonia & N-donor Ligands” in Encyclopedia of Inorganic Chemistry John Wiley & Sons, 2006. {{DOI|10.1002/0470862106.ia009}}.</ref> In contrast, for [Co(trien)X<sub>2</sub>]<sup>+</sup> five diastereoiomers are possible, four of which are chiral.  In a few cases, tren serves as a tridentate ligand with one of the primary amine groups non-coordinated. 
[[Image:TrenCmpxs.png|thumb|left|300px|Structures of trigonal bipyramidal and octahedral complexes of the formulae M(tren)X (left, ''C''<sub>3''v''</sub> symmetry) and M(tren)X<sub>2</sub> (right, ''C''<sub>''s''</sub> symmetry).]]

===Related tripodal ligands===
The permethylated derivative of tren is also well known.  With the formula N(CH<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>)<sub>3</sub>, "Me<sub>6</sub>tren," forms a variety of complexes but, unlike tren, does not stabilize Co(III).  Related amino-triphosphines are also well developed, such as N(CH<sub>2</sub>CH<sub>2</sub>PPh<sub>2</sub>)<sub>3</sub> (m.p. 101-102 °C).  This species is prepared from the nitrogen mustard [[Tris(2-chloroethyl)amine|N(CH<sub>2</sub>CH<sub>2</sub>Cl)<sub>3</sub>]].<ref>R. Morassi, L. Sacconi "Tetradentate Tripod Ligands Containing Nitrogen, Sulfur, Phosphorus, and Arsenic as Donor Atoms" Inorganic Syntheses, 1976, vol. 16 p. 174-180. {{DOI|10.1002/9780470132470.ch47}}</ref>

The tripodal ligand of greatest commercial significance is [[nitrilotriacetic acid|nitrilotriacetate]], N(CH<sub>2</sub>CO<sub>2</sub><sup>-</sup>)<sub>3</sub>.

==Organic chemistry==
Tren is a common impurity in the more common [[triethylenetetramine]] ("trien"). As a trifunctional amine, tren forms a tri[[isocyanate]] when derivatized with [[phosgene|COCl<sub>2</sub>]].<ref name=presschem>[http://www.presschem.com/tris(2-aminoethyl)amine.htm Pressure Chemical]</ref>

==Safety considerations==
(NH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>)<sub>3</sub>N, like other polyamines, is corrosive.<ref>[http://msds.chem.ox.ac.uk/TR/tris(2-aminoethyl)amine.html  The Physical and Theoretical Chemistry Laboratory Oxford University MSDS]</ref>

==References==
{{reflist}}
*[http://www.sigmaaldrich.com/catalog/search/ProductDetail/FLUKA/30662 Sigma Aldrich]

[[Category:Amines]]
[[Category:Coordination chemistry]]
[[Category:Polyamines]]
[[Category:2Fix]]