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Class: Fluorone
Ionisation: Acid

Common Name: Eosinol
Suggested Name: Eosinol Y
Other Names:

Eosine acid Tetrabromofluorescein Eosin Y, spirit soluble

C.I. Number: 45380.2
C.I. Name: Solvent red 43
Color: Red
Solubility Aqueous: Slight
Solubility Ethanol: Slight
Absorption Maximum: 524 (Aldrich), 537 (Gurr)
Empirical Formula: C20H8Br4O5
Formula Weight: 647.9


The colored anion of eosin Y, and sometimes that of eosin B, are referred to as eosinol. They may be sold under the name eosin Y, spirit soluble and eosin B, spirit soluble. Eosin Y and Eosin B themselves are the sodium salts of these anions.

Compare the formula of the eosinols above to that of fluorescein.

Although eosinol is used to refer to the eosin Y anion primarily, the anion of many of the eosin homologs probably could be made in a similar fashion.


  1. Susan Budavari, Editor,
    The Merck Index, Ed. 12
    Merck & Co., Inc., Whitehouse Station, NJ, USA
  2. Aldrich chemical catalogue, 1992
    Aldrich Chemical Company, Milwaukee, WI, USA.
  3. Edward Gurr, 1971
    Synthetic dyes in biology, medicine and chemistry
    Academic Press, London, England.