3602. Eosine I Bluish

Nomenclature

CAS number: 548-24-3
4′,5′-Dibromo-3′,6′-dihydroxy-2′,7′-dinitrospiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one disodium salt; 4′,5′-dibromo-2′,7′-dinitrofluorescein disodium salt; hydroxydibromodinitro-o-carboxyphenylfluorone sodium; C.I. Acid Red 91; C.I. 45400.
C20H6Br2N2Na2O9; mol wt 624.06.
C 38.49%, H 0.97%, Br 25.61%, N 4.49%, Na 7.37%, O 23.07%.

Description and references

Prepd by nitration of 4′,5′-dibromofluorescein: Colour Index vol. 4 (3rd ed., 1971) p 4427.

Chemical structure

Properties

Red powder. Freely sol in water with green fluorescence; sol in alc.

Use

Dyeing wool, cotton, and paper. In histology as a stain for epithelia, muscular fibers, nuclei, etc.