:Tris(2-aminoethyl)amine
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 441445624
| ImageFile = Tris(2-aminoethyl)amine.svg
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageName = Skeletal formula of tris(2-aminoethyl)amino
| PIN = N1,N1-Bis(2-aminoethyl)ethane-1,2-diamine
| OtherNames = {{bulletedlist|2,2′,2′′-Nitrilotri(ethan-1-amine)|2,2′,2′′-Nitrilotriethylamine|2,2′,2′′-Triaminotriethylamine|TAEA}}
|Section1={{Chembox Identifiers
| CASNo = 4097-89-6
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo1 = 14350-52-8
| CASNo1_Comment = (3 HCl)
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 3GY3QSG6H5
| PubChem = 77731
| ChemSpiderID = 70131
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| EINECS = 223-857-4
| UNNumber = 2922
| MeSHName = Tris(2-aminoethyl)amine
| ChEBI = 30631
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 19823
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| RTECS = KH8587082
| Beilstein = 1739626
| Gmelin = 27074
| SMILES = NCCN(CCN)CCN
| StdInChI = 1S/C6H18N4/c7-1-4-10(5-2-8)6-3-9/h1-9H2
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = MBYLVOKEDDQJDY-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
}}
|Section2={{Chembox Properties
| C=6 | H=18 | N=4
| Appearance = Colorless liquid
| Odor = Ichtyal, ammoniacal
| Density = 0.976 g/mL (20 °C){{cite web | url = http://www.sigmaaldrich.com/catalog/product/aldrich/225630 | publisher = Sigma-Aldrich | title = Tris(2-aminoethyl)amine}}
| MeltingPtC = −16
| BoilingPtC = 265
| Solubility = Miscible
| LogP = −2.664
| VaporPressure = 3 Pa (at 20 °C)
}}
|Section3={{Chembox Thermochemistry
| DeltaHf = −74.3–−72.9 kJ mol−1
| DeltaHc = −4860.6–−4859.2 kJ mol−1
}}
|Section4={{Chembox Hazards
| ExternalSDS = [https://fscimage.fishersci.com/msds/98548.htm fishersci.com]
| GHSPictograms = {{gHS corrosion}} {{gHS skull and crossbones}}
| GHSSignalWord = DANGER
| HPhrases = {{h-phrases|301|310|314}}
| PPhrases = {{p-phrases|280|302+350|305+351+338|310}}
| FlashPtC = 113
| LD50 = {{unbulleted list|117 mg kg−1 (dermal, rabbit)|246 mg kg−1 (oral, rat)}}
}}
|Section5={{Chembox Related
| OtherFunction_label = amines
| OtherFunction = {{unbulleted list|Dimethylamine|Trimethylamine|N-Nitrosodimethylamine|Diethylamine|Triethylamine|Diisopropylamine|Dimethylaminopropylamine|Diethylenetriamine|N,N-Diisopropylethylamine|Triisopropylamine|Mechlorethamine|HN1 (nitrogen mustard)|HN3 (nitrogen mustard)}}
| OtherCompounds = {{unbulleted list|Unsymmetrical dimethylhydrazine|Biguanide|Dithiobiuret|Agmatine}}
}}
}}
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. Tris(2-aminoethyl)amine is commonly abbreviated as tren or TREN. It is used a crosslinking agent in the synthesis of polyimine networks and a tripodal ligand in coordination chemistry.
Supramolecular and polymer derivatives
Tris(2-aminoethyl)amine has been used to prepare molecular capsules and related supramolecular structures.{{cite journal |doi=10.1002/adfm.201404553 |title=Vinylogous Urethane Vitrimers |date=2015 |last1=Denissen |first1=Wim |last2=Rivero |first2=Guadalupe |last3=Nicolaÿ |first3=Renaud |last4=Leibler |first4=Ludwik |last5=Winne |first5=Johan M. |last6=Du Prez |first6=Filip E. |journal=Advanced Functional Materials |volume=25 |issue=16 |pages=2451–2457 |hdl=11336/2888 |s2cid=95154324 |hdl-access=free }}{{cite journal |doi=10.1038/nbt1402 |title=A combinatorial library of lipid-like materials for delivery of RNAi therapeutics |date=2008 |last1=Akinc |first1=Akin |last2=Zumbuehl |first2=Andreas |last3=Goldberg |first3=Michael |last4=Leshchiner |first4=Elizaveta S. |last5=Busini |first5=Valentina |last6=Hossain |first6=Naushad |last7=Bacallado |first7=Sergio A. |last8=Nguyen |first8=David N. |last9=Fuller |first9=Jason |last10=Alvarez |first10=Rene |last11=Borodovsky |first11=Anna |last12=Borland |first12=Todd |last13=Constien |first13=Rainer |last14=De Fougerolles |first14=Antonin |last15=Dorkin |first15=J Robert |last16=Narayanannair Jayaprakash |first16=K. |last17=Jayaraman |first17=Muthusamy |last18=John |first18=Matthias |last19=Koteliansky |first19=Victor |last20=Manoharan |first20=Muthiah |last21=Nechev |first21=Lubomir |last22=Qin |first22=June |last23=Racie |first23=Timothy |last24=Raitcheva |first24=Denitza |last25=Rajeev |first25=Kallanthottathil G. |last26=Sah |first26=Dinah W Y. |last27=Soutschek |first27=Jürgen |last28=Toudjarska |first28=Ivanka |last29=Vornlocher |first29=Hans-Peter |last30=Zimmermann |first30=Tracy S. |journal=Nature Biotechnology |volume=26 |issue=5 |pages=561–569 |pmid=18438401 |pmc=3014085 |display-authors=1 }}{{cite journal |doi=10.1021/ja027184x |title=Influencing Receptor−Ligand Binding Mechanisms with Multivalent Ligand Architecture |date=2002 |last1=Gestwicki |first1=Jason E. |last2=Cairo |first2=Christopher W. |last3=Strong |first3=Laura E. |last4=Oetjen |first4=Karolyn A. |last5=Kiessling |first5=Laura L. |journal=Journal of the American Chemical Society |volume=124 |issue=50 |pages=14922–14933 |pmid=12475334 }}
Metal complexes
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.Donald A. House "Ammonia & N-donor Ligands" in Encyclopedia of Inorganic Chemistry John Wiley & Sons, 2006. {{doi|10.1002/0470862106.ia009}}. In contrast, for [Co(trien)X2]+ five diastereomers 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. Tren is a common impurity in the more common triethylenetetramine ("trien"). As a trifunctional amine, tren forms a triisocyanate when derivatized with COCl2.
TREN is known to react fast in the presence of (aromatic) aldehydes to form an imine. During this process, water is formed, making it a condensation reaction. Due to this fast and efficient reaction, TREN is commonly used in the preparation of polyimines.{{Cite journal| last = Schoustra| first = Sybren K.| author2 = Dijksman, Joshua A.| author3= Zuilhof, Han| author4 = Smulders, Maarten M. J.| title = Molecular control over vitrimer-like mechanics – tuneable dynamic motifs based on the Hammett equation in polyimine materials | journal = Chemical Science |year=2021 | volume = 12 | issue = 1| pages = 293–302 | doi = 10.1039/D0SC05458E| pmid = 34163597| pmc = 8178953}}
Image:TrenCmpxs.png{{clear-left}}
=N-methylated derivatives=
The permethylated derivative of tren has 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.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}}
N,N,N-trimethyltren, N(CH2CH2NHMe)3 is also available.{{cite journal|doi = 10.1002/zaac.19895780109|title = New Prophosphatranes: Novel intermediates to five-coordinate phosphatranes|journal = Zeitschrift für Anorganische und Allgemeine Chemie|volume = 578|pages = 75–80|year = 1989|last1 = Schmidt|first1 = H.|last2 = Lensink|first2 = C.|last3 = Xi|first3 = S. K.|last4 = Verkade|first4 = J. G.}}
Safety considerations
(H2NCH2CH2)3N, like other polyamines, is corrosive.{{Cite web |url=http://msds.chem.ox.ac.uk/TR/tris(2-aminoethyl)amine.html |title=The Physical and Theoretical Chemistry Laboratory Oxford University MSDS |access-date=2008-04-19 |archive-date=2011-01-18 |archive-url=https://web.archive.org/web/20110118023058/http://msds.chem.ox.ac.uk/TR/tris(2-aminoethyl)amine.html |url-status=dead }} It causes severe skin burns and eye damage, is harmful if inhaled due to the destruction of respiratory tissues, is toxic if swallowed, and can be fatal in contact with skin. Its median lethal dose is 246 mg/kg, oral (rat), and 117 mg/kg, dermal (rabbit). It is also combustible.{{cite web | url=https://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do?country=US&language=en&productNumber=225630&brand=ALDRICH&PageToGoToURL=https%3A%2F%2Fwww.sigmaaldrich.com%2Fcatalog%2Fproduct%2Faldrich%2F225630%3Flang%3Den | title=Safety Data Sheet | publisher=Sigma-Aldrich | date=July 1, 2014 | accessdate=April 7, 2019}}