1-Vinylimidazole (CAS 1072-63-5) is the smallest molecule that combines two useful functions: a polymerisable vinyl group and an imidazole ring that is basic, coordinating and hydrogen-bonding. That combination makes it the monomer behind polyvinylimidazole, vinylpyrrolidone copolymers, polymerised ionic liquids and a family of polymer electrolytes. PolyBlueChem supplies it as a colourless to yellowish liquid, purity 98.0% min, water 0.5% max, with per-batch COA and SDS.
Specifications
| Property | Specification |
|---|---|
| Appearance | Colourless to yellowish liquid |
| Purity (assay) | 98.0% min |
| Water content | 0.5% max |
| CAS number | 1072-63-5 |
| Formula / MW | C5H6N2 / 94.11 g/mol |
| Boiling point | About 192-194 °C (typical literature value) |
| Density | About 1.04 g/cm3 at 25 °C (typical) |
| Refractive index | About 1.53 (nD20, typical) |
| Inhibitor | Supplied with a polymerisation inhibitor – confirm type and level on the COA |
| Storage | Sealed, cool, dark, inert gas preferred; keep below the recommended storage temperature |
Physical constants are quoted as typical literature values because they vary slightly by lot and by measurement method; the three figures that define the commercial product are appearance, assay and water. The fourth, unlisted item is the polymerisation inhibitor – see below, because it matters more than most buyers expect.
Basic Information
| CAS number | 1072-63-5 |
| Chemical name | 1-Vinylimidazole; 1-ethenyl-1H-imidazole; N-vinylimidazole |
| Formula / MW | C5H6N2 / 94.11 g/mol |
| PubChem CID | 66171 |
| Functional groups | N-vinyl (radical and cationic polymerisation) + imidazole (weak base, metal coordination, hydrogen bonding) |
| Type | Polymerisable heterocyclic monomer |
Why this molecule is useful: two functions in one small package
| Part of the molecule | What it does | What it enables |
|---|---|---|
| Vinyl group on the ring nitrogen | Undergoes free-radical (and cationic) polymerisation | Can be homopolymerised or copolymerised into a backbone, so the imidazole becomes a pendant group on a polymer chain |
| Imidazole ring | Weak base (pKa around 7 on the conjugate acid), coordinates metal ions, forms hydrogen bonds, can be quaternised | Metal capture, buffering, catalysis, CO2 interaction, and a handle for making ionic liquids |
| Secondary nitrogen in the ring | Can be alkylated or protonated | Turns the polymer into a cationic polyelectrolyte or a polymerised ionic liquid |
A buyer who needs an imidazole that cannot polymerise uses 1-methylimidazole (CAS 616-47-7) instead; a buyer who needs a polymerisable amide uses N-vinylpyrrolidone (CAS 88-12-0). 1-Vinylimidazole is the intersection of the two, which is precisely why it is more expensive than either.
Where it goes
- Polyvinylimidazole (PVIm) – a water-soluble, weakly basic polymer used for metal-ion capture, as a flocculant and as a polymer support for catalysts.
- Copolymers with N-vinylpyrrolidone – PVP/PVI copolymers combine the film-forming and complexing behaviour of PVP with the cationic character of the imidazole; used in personal care, pharmaceutical carriers, membranes and surface modification.
- Polymerised ionic liquids (PILs) – quaternisation of the ring nitrogen gives an imidazolium salt; polymerisation then gives a solid ionic conductor used in gas separation, CO2 capture and electrochemistry.
- Crosslinked adsorbent resins – copolymerised with acrylamide or acrylic acid to give chelating resins for heavy metals.
- Polymer electrolytes and membranes – the imidazole ring can act as a proton carrier, which is why it appears in anhydrous proton-conducting membranes and fuel-cell work.
- Grafting and surface functionalisation – the vinyl group allows covalent attachment onto a substrate or a pre-formed polymer.
The handling problem that defines this product
1-Vinylimidazole polymerises spontaneously – slowly at room temperature, faster with heat, light or trace radical initiators. Everything about buying and storing it follows from that.
| Issue | Practical consequence | What to do |
|---|---|---|
| The product ships with an inhibitor | Assay is measured on the inhibited material; the inhibitor is not part of the purity figure but it does enter your reaction | Confirm the inhibitor type and level, and confirm whether it must be removed before your polymerisation |
| Inhibited material still ages | A drum held hot for months can show viscosity rise or gel particles even though the assay passes | Buy to consumption; store cool, dark and sealed; consider nitrogen padding |
| Inhibitor interferes with some polymerisations | Radical polymerisation can show a long induction period or a low molecular weight | Remove the inhibitor by distillation or by passing over a suitable adsorbent – established practice, but a step to plan for |
| Water content matters | Water affects polymerisation kinetics, the purity of the ionic-liquid salts made from it, and corrosion in metal equipment | Keep the 0.5% limit on the specification and check it on receipt |
This is the single most useful thing to ask a supplier beyond the assay: which inhibitor and how much. Two suppliers can both deliver 98% product and behave completely differently in a reactor.
Buying notes
- Ask for the inhibitor identity and concentration, and whether the material can be supplied uninhibited against a specific requirement.
- Specify water content – it is on the certificate for a reason, and it is the cheapest early warning of a drum that has been opened repeatedly.
- Check colour: a shift from colourless towards yellow-brown is the first visible sign of oligomerisation.
- Consider packaging size against consumption: a large drum of a self-polymerising monomer is an inventory risk, not an economy.
- Handle as a corrosive, flammable liquid – follow the SDS for storage segregation, personal protective equipment and spill response.
Packaging and supply
Supplied in steel or HDPE drums and in smaller sealed containers, under nitrogen where requested. Store cool, dry and out of direct light, keep containers closed, and respect the shelf-life declared on the certificate – for a self-polymerising monomer this is not a formality. Each lot ships with a COA and SDS, with FOB or CIF terms quoted against destination. Where the material feeds a regulated application, say so at enquiry stage so the documentation package is built with the first lot.
Further reading
- 1-Vinylimidazole: from monomer to polyvinylimidazole, ionic liquids and polymer electrolytes
- 1-Vinylimidazole vs 1-methylimidazole vs N-vinylpyrrolidone: which monomer you actually need
- Polyvinylimidazole: how it is made and where it is used
PolyBlueChem supplies 1-vinylimidazole (CAS 1072-63-5), purity 98.0% min, water 0.5% max, colourless to yellowish liquid, with per-batch COA and SDS and FOB/CIF delivery. Tell us the polymerisation route and your inhibitor requirement, and we will confirm the grade and the packaging.
