| Boiling Point | 84°C |
| Melting Point | 97–99°C (lit.) |
| Color | Yellow |
| Formula Weight | 55.08 |
| Physical Form | Powder |
| Chemical Name or Material | Benzotriazole |
| UN Number | 3286 |
| Molecular Weight | 119.12 g/mol |
| SMILES String | c1ccc2[nH]nnc2c1 |
| CAS Number | 95-14-7 |
| EC Number | 202-394-1 |
| Empirical Formula | C6H5N3 |
| NACRES | NA.21 |
| PubChem Substance ID | 57653915 |
| UNSPSC Code | 12352100 |
| MDL Number | MFCD00005699 |
| InChI | 1S/C6H5N3/c1-2-4-6-5(3-1)7-9-8-6/h1-4H,(H,7,8,9) |
| InChI Key | QRUDEWIWKLJBPS-UHFFFAOYSA-N |
| Beilstein/REAXYS Number | 112133 |
| Quality Level | 200 |
| Reference Grade | ReagentPlus®, 99% |
Benzotriazole is a bicyclic heterocycle combining a benzene ring fused to a triazole ring — three nitrogen atoms in a five-membered ring. That nitrogen-rich structure lets the molecule bind strongly to copper surfaces, forming a thin protective film that blocks oxidation and tarnishing, which is the chemical basis for its role as a corrosion inhibitor for copper and its alloys.
Benzotriazole’s most widespread industrial use is protecting copper and copper-alloy components from corrosion, particularly in automotive antifreeze/coolant formulations and metalworking fluids, where even trace amounts significantly extend component life. Its ring system is also the structural core of a major class of UV light stabilizers used to protect plastics and coatings from photodegradation. In synthetic chemistry, it serves as a synthetic auxiliary and reactant — for example, in Mannich-type reactions to build β-aminocarbonyl compounds, and in forming acylbenzotriazoles as activated acylating agents.
