Tetramethyl orthosilicate
Also known as: TMOS, Methyl silicate, Tetramethoxysilane, Methyl orthosilicate, Silicon tetramethoxide, Tetramethyl silicate, Orthosilicic acid tetramethyl ester, Dynasil M, EINECS 211-656-4, MFCD00008341
Tetramethyl orthosilicate (CAS 681-84-5) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C4H12O4Si and a molecular weight of 152.221 g/mol. Key properties include a melting point of −4 °C(lit.), a boiling point of 121.2±8.0 °C at 760 mmHg, a density of 1.0±0.1 g/cm3 and a flash point of 28.9±0.0 °C. It is classified under GHS with signal word Danger and hazard statements H226 — Flammable liquid and vapour, H315 — Causes skin irritation and H318 — Causes serious eye damage. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 681-84-5
- Jingsj CID
- J-47492-0
- Molecular Formula
- C4H12O4Si
- Molecular Weight
- 152.221 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Melting Point | −4 °C(lit.) |
|---|---|
| Boiling Point | 121.2±8.0 °C at 760 mmHg |
| Density | 1.0±0.1 g/cm3 |
| Flash Point | 28.9±0.0 °C |
| Exact Mass | 152.050491 |
| PSA | 36.92000 |
| LogP | 2.97 |
| Additional Property | 5.25 (vs air) |
| Vapor Pressure | 17.7±0.2 mmHg at 25°C |
| Refractive Index | 1.382 |
| Additional Property | hydrolysis |
GHS Safety & Compliance
- H226 — Flammable liquid and vapour
- H315 — Causes skin irritation
- H318 — Causes serious eye damage
- H330 — Fatal if inhaled
Customs & Trade Information
| HS Code | 2920909090 |
|---|---|
| Summary | 2920909090 esters of other inorganic acids of non-metals (excluding esters of hydrogen halides) and their salts; their halogenated, sulphonated, nitrated or nitrosated derivatives。Supervision conditions:None。VAT:17.0%。Tax rebate rate:9.0%。MFN tariff:6.5%。General tariff:30.0% |
Frequently Asked Questions
What is the CAS number of Tetramethyl orthosilicate?
The CAS number of Tetramethyl orthosilicate is 681-84-5.
What are the molecular formula and molecular weight of Tetramethyl orthosilicate?
Tetramethyl orthosilicate has molecular formula C4H12O4Si and molecular weight 152.221 g/mol.
Is Tetramethyl orthosilicate hazardous?
Tetramethyl orthosilicate has GHS signal word Danger and hazard statements H226 — Flammable liquid and vapour; H315 — Causes skin irritation; H318 — Causes serious eye damage.
What are the upstream and downstream products of Tetramethyl orthosilicate?
For Tetramethyl orthosilicate, Upstream Products: Methanol, Tetrachlorosilane, Silicon; Downstream Products: 2,4-Dimethoxy-1-nitrobenzene, Tetrabutyl orthosilicate, Trimethoxy(3,3,3-trifluoropropyl)silane.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "Tetramethyl orthosilicate (CAS 681-84-5)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-47492-0 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.