is the chemical compound
with the formula N(CH2
. 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 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)X2
, where X is halide or pseudohalide. In contrast, for [Co(trien)X2
five diastereoiomers are possible, four of which are chiral.
Related tripodal ligands
The permethylated derivative of tren is also well known. With the formula N(CH2
tren," forms a variety of complexes but, unlike tren itself, does not stabilize Co(III). Related triphosphines are also well developed, such as N(CH2
(m.p. 101-102 °C). This species is prepared from the nitrogen mustard N(CH2CH2Cl)3
The tripodal ligand of greatest commercial significance is nitrilotriacetate, N(CH2CO2-)3.
Tren is a common impurity in the more common triethylenetetramine
("trien"). As a trifunctional amine, tren forms a triisocyanate
when derivatized with COCl2
N, like other polyamines, is corrosive.