Tris(2-aminoethyl)amine (TREN, CAS 4097-89-6) is a branched tetraamine: three 2-aminoethyl arms built on a single tertiary nitrogen. PolyBlueChem supplies it as a pale yellow to colourless liquid at 98.0% min by GC with 0.5% max water, with per-batch COA and SDS.
TREN matters because of a single structural fact: it is a branched isomer of triethylenetetramine (TETA). Same molecular formula C6H18N4, same molecular weight 146.2, same amine equivalent weight 24.4 g/eq – and yet a different molecule in use, because TREN carries one tertiary nitrogen where TETA carries a secondary one. That single substitution changes cure catalysis, chelate geometry and the way the molecule picks up CO2.
Specifications
| Property | Specification |
|---|---|
| Appearance | Pale yellow to colourless liquid |
| Purity (GC) | 98.0% min |
| Moisture (Karl Fischer) | 0.5% max |
| CAS number | 4097-89-6 |
| Formula | C6H18N4 |
| Molecular weight | 146.23 g/mol |
| PubChem CID | 77731 |
| SMILES | NCCN(CCN)CCN |
| Nitrogen content (calculated) | 38.3% |
| Amine equivalent weight (calculated, 6 active H) | 24.4 g/eq |
Both calculated figures are derived from the formula and are useful as cross-checks on a supplier’s assay: 4 x 14.007 / 146.23 = 38.3% nitrogen, and 146.23 / 6 = 24.4 g per equivalent of active hydrogen.
TREN vs TETA: same formula, different molecule
| Property | TREN (this product) | TETA |
|---|---|---|
| CAS | 4097-89-6 | 112-24-3 |
| Formula / MW | C6H18N4 / 146.23 | C6H18N4 / 146.24 |
| Structure | Branched: (H2NCH2CH2)3N | Linear: H2N(CH2)2NH(CH2)2NH(CH2)2NH2 |
| Amine types | 3 primary + 1 tertiary | 3 primary + 1 secondary |
| Active hydrogens | 6 | 6 |
| Amine equivalent weight | 24.4 g/eq | 24.4 g/eq |
| Epoxy behaviour | Self-accelerating (tertiary N catalyses the epoxy ring opening) | Not self-accelerating; usually needs an accelerator for thin-film or low-temperature cure |
| Chelation geometry | Pre-organised tetradentate N4 pocket – one ligand wraps one metal ion | Linear chain that must fold around the metal; weaker pre-organisation |
| Quantity normally traded | Distilled speciality grade, usually 98% plus | Bulk commodity ethyleneamine, several grades |
The practical consequence: the stoichiometric calculation is identical, but the cure behaviour is not. If you substitute TREN for TETA weight-for-weight, the gel time and the low-temperature cure will both change. Substitute on an equivalent basis only, and re-check pot life.
Why the 0.5% water limit is a real specification
Polyamines are hygroscopic and, more importantly, carbon dioxide scavengers. Absorbed CO2 reacts with the primary amines to form carbamates and carbonates, which show up as haze, sediment or a falling titration. In an epoxy system that means a cure that looks under-cured at correct stoichiometry, and in a chelation or gas-treating system it means active amine you have paid for but cannot use. Moisture and CO2 pickup go together, so the Karl Fischer figure on the COA is the cheapest proxy for how well the drum has been kept sealed.
On receipt: keep the drum closed, blanketed with dry nitrogen where available, and store under dry, ventilated conditions away from acids, oxidising agents and copper or aluminium (amines attack these). Do not decant into unlabelled containers – TREN is corrosive and its hazard profile is not visible from the liquid itself.
Main uses
- Epoxy curing agent and chain extender – 6 active hydrogens per molecule, self-catalysing through the tertiary nitrogen. Used in coatings, adhesives and composites where a fast, room-temperature or low-temperature cure is wanted.
- Chelating ligand and chelate intermediate – a classic tetradentate N4 ligand for Cu(II), Zn(II) and Ni(II), and the starting scaffold for ligands, catalysts and chelating polymers.
- Gas treating and CO2 capture – the three primary amines react with CO2; TREN is one of the polyamines studied as a high-capacity absorbent in amine scrubbing research.
- Dendrimer and polymer building block – the branch point for PAMAM-type and other hyperbranched architectures.
- Intermediate for surfactants, lubricant additives and asphalt emulsifiers – where a multifunctional amine head group is required.
Buying notes
- Buy on GC assay, not on total nitrogen. Nitrogen titration cannot tell TREN from TETA, DETA or EDA – and the price difference is entirely in the isomer.
- Ask for the isomer distribution if the application is epoxy curing or chelation. A "98% tetraamine" can still be a mixture of branched and linear cuts.
- Check water and colour together. A water figure inside specification with a darker-than-expected liquid usually means CO2 pickup rather than a moisture problem.
- State the end use so the documentation matches – a coatings buyer and a chelate-synthesis buyer need different paperwork for the same CAS.
- Small volumes are normal for this product. TREN is a speciality cut, not a bulk solvent; 1 kg, 5 kg and 25 kg packs are standard alongside 200 kg drums.
Packaging and supply
Supplied in 200 kg steel or HDPE drums, 25 kg jerricans and, for development work, 1 kg and 5 kg packs – all under dry nitrogen where the pack format allows. Every lot ships with a COA and a current SDS, FOB or CIF against destination. Because the material degrades through CO2 and moisture pickup rather than through freezing, pack integrity and headspace matter more than warehouse temperature; keep drums sealed and use them in rotation.
Hazard notice: TREN is corrosive. It causes severe skin burns and eye damage, is harmful if inhaled or swallowed, and can cause an allergic skin reaction. Handle with chemical-resistant gloves, eye and face protection and adequate ventilation; avoid breathing vapour or mist. Never work with it while wearing alcohol-based hand sanitiser residue or in contact with nitrites – secondary and tertiary amines are nitrosamine precursors, and the handling rules for this class exist for that reason. Refer to the SDS for full transport, first-aid and disposal information.
Further reading
- Tris(2-aminoethyl)amine (TREN), CAS 4097-89-6: properties, manufacture and applications
- TREN vs TETA vs DETA: choosing a polyamine for curing and chelation
- How to buy tris(2-aminoethyl)amine: grades, packaging and acceptance tests
FAQ
Is TREN the same as TETA?
No. They share the formula C6H18N4 and the molecular weight 146.2 but are structural isomers: TREN is branched with a tertiary nitrogen, TETA is linear with a secondary nitrogen. The amine equivalent weight is the same; the cure and chelation behaviour is not.
What grade do you supply?
98.0% min by GC, water 0.5% max, pale yellow to colourless liquid, in 1 kg to 200 kg packs. Higher-assay distilled grades and custom water limits are available against enquiry.
Can you supply a COA with the isomer distribution?
Yes – state the requirement at enquiry stage and the batch documentation is issued against the specification you need, including residual linear polyamine where the application is sensitive to it.
PolyBlueChem supplies tris(2-aminoethyl)amine (TREN, CAS 4097-89-6) at 98.0% min GC with 0.5% max water, in development packs through to 200 kg drums, with per-batch COA and SDS and FOB/CIF delivery. Tell us the application and the pack size, and we will confirm the grade and the documentation.
