8183. Rhodamine B

Nomenclature

CAS number: 81-88-9
9-(2-carboxyphenyl)-3,6-bis(diethylamino)xanthylium chloride; N-[9-(2-Carboxyphenyl)-6-(diethylamino)-3H-xanthen-3-ylidene]-N-ethylethanaminium chloride; tetraethylrhodamine; D & C Red No. 19; C.I. Basic Violet 10; C.I. 45170.
C28H31ClN2O3; mol wt 479.01.
C 70.21%, H 6.52%, Cl 7.40%, N 5.85%, O 10.02%.

Description and references

Prepn: Colour Index vol. 4 (3rd ed., 1971) p 4420. Toxicity study: J. M. Webb et al., Toxicol. Appl. Pharmacol. 3, 696 (1961).

Chemical structure

Properties

Green crystals or reddish-violet powder. Very sol in water with a bluish-red color, dil solns being strongly fluorescent; very sol in alcohol; slightly sol in HCl, NaOH. LD50 i.v. in rats: 89.5 mg/kg (Webb).

Use

As a dye, especially for paper; as a reagent for antimony, bismuth, cobalt, niobium, gold, manganese, mercury, molybdenum, tantalum, thallium, tungsten; as biological stain. Provisionally listed for use in drugs and cosmetics.