Eosin Y free acid

Also known as: 2',4',5',7'-Tetrabromofluorescein, C.I. 45380 (free acid), Bromofluoresceic acid, Eosin yellowish (free acid), Solvent Red 45

Eosin Y free acid (CAS 548-26-5) is a compound in the Organohalogen Compounds category listed in the Jingsj chemical database. It has the molecular formula C20H6Br4KO5 and a molecular weight of 684.97700 g/mol. Key properties include a boiling point of 682.3ºC at 760 mmHg, a density of 2.41 g/cm3 and a flash point of 366.5ºC. No supplier offers are currently listed; request a quote. Record last updated Nov 2, 2026.

CAS No.: 548-26-5
Jingsj CID: J-1517247-7
Molecular Formula: C₂₀H₆Br₄KO₅
Molecular Weight: 684.97700 g/mol
Category: Organohalogen Compounds
Last updated: 11/2/2026

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Physicochemical Properties

Boiling Point	682.3ºC at 760 mmHg
Density	2.41 g/cm3
Flash Point	366.5ºC
Exact Mass	643.71100
PSA	75.99000
LogP	6.71580
Refractive Index	1.842

Customs & Trade Information

HS Code	2932999099
Summary	2932999099. other heterocyclic compounds with oxygen hetero-atom(s) only. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:20.0%

Frequently Asked Questions

What is the CAS number of Eosin Y free acid?

The CAS number of Eosin Y free acid is 548-26-5.

What are the molecular formula and molecular weight of Eosin Y free acid?

Eosin Y free acid has molecular formula C20H6Br4KO5 and molecular weight 684.97700 g/mol.

What are the upstream and downstream products of Eosin Y free acid?

For Eosin Y free acid, Downstream Products: Eosin Y (alcohol soluble), Ethyl eosin.

Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.

Last updated: 11/2/2026

How to cite: Jingsj. "Eosin Y free acid (CAS 548-26-5)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1517247-7 (accessed 2026-11-06).

Data for reference only; verify product details with suppliers before purchase.