|Molar mass||146.23 g·mol−1|
|Density||977 mg mL−1|
|Melting point||−16 °C (3 °F; 257 K)|
|Boiling point||265 °C (509 °F; 538 K)|
|Vapor pressure||3 Pa (at 20 °C)|
Refractive index (nD)
Std enthalpy of
|−74.3–−72.9 kJ mol−1|
Std enthalpy of
|−4860.6–−4859.2 kJ mol−1|
|GHS signal word||DANGER|
|H301, H310, H314|
|P280, P302+350, P305+351+338, P310|
|R-phrases||R22, R24, R34|
|Flash point||113 °C (235 °F; 386 K)|
LD50 (Lethal dose)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
Tris(2-aminoethyl)amine is the organic compound with the formula N(CH2CH2NH2)3. 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.
Tren is a C3-symmetric, 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)X2]+, where X is halide or pseudohalide. In contrast, for [Co(trien)X2]+ 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.
Related tripodal ligands
The permethylated derivative of tren is also well known. With the formula N(CH2CH2NMe2)3, "Me6tren," forms a variety of complexes but, unlike tren, does not stabilize Co(III). Related amino-triphosphines are also well developed, such as N(CH2CH2PPh2)3 (m.p. 101-102 °C). This species is prepared from the nitrogen mustard N(CH2CH2Cl)3. Tren is a common impurity in the more common triethylenetetramine ("trien"). As a trifunctional amine, tren forms a triisocyanate when derivatized with COCl2.
(NH2CH2CH2)3N, like other polyamines, is corrosive.
- Donald A. House "Ammonia & N-donor Ligands" in Encyclopedia of Inorganic Chemistry John Wiley & Sons, 2006. doi:10.1002/0470862106.ia009.
- 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
- Pressure Chemical
- The Physical and Theoretical Chemistry Laboratory Oxford University MSDS