Tetraethyl pyrophosphite
Also known as: Bis(diethoxyphosphino) ether, Bis(phosphorous acid diethyl)anhydride, Diphosphorous acid tetraethyl ester, Oxybis(diethoxyphosphine), Oxybis(phosphonous acid diethyl) ester, diethoxyphosphanyl diethyl phosphite, tetraethyldiphosphite
Tetraethyl pyrophosphite (CAS 21646-99-1) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C8H20O5P2 and a molecular weight of 258.18900 g/mol. Key properties include a boiling point of 237.9ºC at 760mmHg, a density of 1.057 g/mL at 25 °C(lit.) and a flash point of 115.2ºC. It is classified under GHS with signal word Warning and hazard statements H315 — Causes skin irritation, H319 — Causes serious eye irritation and H335 — May cause respiratory irritation. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.
- CAS No.
- 21646-99-1
- Jingsj CID
- J-1993530-9
- Molecular Formula
- C8H20O5P2
- Molecular Weight
- 258.18900 g/mol
- Category
- Organic Acids
- Last updated
- 8/21/2026
No offers for this compound yet.
Request a quotePhysicochemical Properties
| Boiling Point | 237.9ºC at 760mmHg |
|---|---|
| Density | 1.057 g/mL at 25 °C(lit.) |
| Flash Point | 115.2ºC |
| Exact Mass | 258.07900 |
| PSA | 73.33000 |
| LogP | 3.60280 |
| Vapor Pressure | 0.0674mmHg at 25°C |
| Refractive Index | n20/D 1.434(lit.) |
GHS Safety & Compliance
- H315 — Causes skin irritation
- H319 — Causes serious eye irritation
- H335 — May cause respiratory irritation
Frequently Asked Questions
What is the CAS number of Tetraethyl pyrophosphite?
The CAS number of Tetraethyl pyrophosphite is 21646-99-1.
What are the molecular formula and molecular weight of Tetraethyl pyrophosphite?
Tetraethyl pyrophosphite has molecular formula C8H20O5P2 and molecular weight 258.18900 g/mol.
Is Tetraethyl pyrophosphite hazardous?
Tetraethyl pyrophosphite has GHS signal word Warning and hazard statements H315 — Causes skin irritation; H319 — Causes serious eye irritation; H335 — May cause respiratory irritation.
What are the upstream and downstream products of Tetraethyl pyrophosphite?
For Tetraethyl pyrophosphite, Upstream Products: Diethyl phosphite, Diethyl chlorophosphite, Triethyl phosphite; Downstream Products: Diethyl acetylphosphonate, Diethyl chlorophosphite, Diethyl (trichloromethyl)phosphonate.
Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.
Last updated:
How to cite: Jingsj. "Tetraethyl pyrophosphite (CAS 21646-99-1)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1993530-9 (accessed 2026-11-09).
Data for reference only; verify product details with suppliers before purchase.