Eosin B

Structural formula
General
Surname	Eosin B
other names	2,7-dinitro-4,5-dibromofluorescein 4 ', 5'-dibromo-3', 6'-dihydroxy-2 ', 7'-dinitro-spiro [phthalan-1,9'-xanthene] -3-one CI 45400
Molecular formula	C 20 H 6 Br 2 N 2 Na 2 O 9
Brief description	brownish green solid
External identifiers / databases
CAS number 548-24-3 (disodium salt) 56360-46-4 (free acid) EC number 208-943-1 ECHA InfoCard 100.008.131 PubChem 29090 Wikidata Q59767930
properties
Molar mass	624.09 g mol −1
Physical state	firmly
solubility	good in water (300 g l −1 at 20 ° C)
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Eosin B is a brownish green dye from the group of xanthene dyes and triphenylmethane dyes . It can be used to dye textiles and paper. In addition to eosin B, eosin Y is also known, which has a wider range of applications than eosin B. Eosin Y has the same basic structure as eosin B, but the nitro groups have been replaced by bromine atoms. The structure of Eosin B is derived from fluorescein .

presentation

The reaction of eosin Y with nitric acid can be used to synthesize eosin B. Here, two bromine atoms are exchanged for nitro groups.

use

Eosin B can be used for hematoxylin-eosin staining in histology and clinical cytology . In preparations, the cytoplasm , collagen and elastin stained with eosin B appear red, while erythrocytes appear red-orange.

Web links

Commons : Eosin B  - Collection of Images, Videos and Audio Files

Individual evidence

1. ↑ ^{a b c d} Eosin B data sheet (PDF) from Merck , accessed December 9, 2010.
2. ↑ A. Baeyer : About the compounds of phthalic acid with phenols , in: Liebigs Ann. , 1876 , 183 , pp. 1-74; doi : 10.1002 / jlac.18761830102 .
3. ↑ Merck KGaA : Hematoxylin-Eosin Staining ( Memento from May 18, 2015 in the Internet Archive ).