Basic Rhodamine

Description

Rhodamine B · CAS 81-88-9 · C28H31N2O3.Cl. UNII K7G5SCF8IL. Other Experimental Properties: 165 °C (anhydrous); Color Additive Status: 81.10; Color Additive Status: 81.30.

Identification

CAS Registry Number	81-88-9
PubChem CID	6694
Molecular formula	C28H31N2O3.Cl
IUPAC name	[9-(2-carboxyphenyl)-6-(diethylamino)xanthen-3-ylidene]-diethylazanium chloride
UNII (FDA)	K7G5SCF8IL

Computed Descriptors

Molecular Weight	479.0
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	7
Exact Mass	478.2023205
Monoisotopic Mass	478.2023205
Topological Polar Surface Area	52.8
Heavy Atom Count	34
Formal Charge	0
Complexity	811

Physical & Chemical Properties

Other Experimental Properties	165 °C (anhydrous)
Color Additive Status	81.10
Color Additive Status	81.30

Physical description & handling notes

• C.i. food red 15 appears as green crystals or reddish-violet powder. Used as a dye, especially for paper, as a metal chelating reagent, and in drugs and cosmetics.
• Green crystals or red-violet powder soluble in water; Dilute solutions are fluorescent. [CAMEO]
• Green crystals or reddish-violet powder.
• GREEN CRYSTALS OR REDDISH-VIOLET POWDER; WATER SOLN WITH BLUISH-RED COLOR, DIL SOLN STRONGLY FLUORESCENT
• LEAFLETS FROM DILUTE HYDROCHLORIC ACID
• SOL IN WATER, ALCOHOL & ETHER, BENZENE /BASIC ANHYDROUS FORM/

Regulatory Status

Regulatory & Food Contact	COLOUR: Food Additives CI FOOD RED 15 NMRS 38/TRS 309-JECFA 8/24 D AND C RED No. 19
GHS notification summary	0.9% (22 / 2557)

GHS Hazard Classification

GHS notification summary	0.9% (22 / 2557)
Reported hazard statements	H302 (13.6%), H318 (98.2%), H412 (93.9%), H335

Documented Uses

• Used as a paper dye, a metal chelating agent, and an additive to drugs and cosmetics; [CAMEO] Rhodamine dyes (aminoxanthenes) are xanthene dyes that are very important commercially. They are brilliant, blue-red, fluorescent dyes used as colorants in inks, paper, and plastics. Sulfonated derivatives are used as wool and polyamide dyes. Red fluorescent pigments are produced from Rhodamine dyes, and some of these are used as laser dyes. Rhodamine B is used to make pink fluorescent pigments. [Ullmann]
• Pulp and Paper Processing [Category: Industry]
• Painting (Pigments, Binders, and Biocides) [Category: Paint]
• AS DYE, ESP FOR PAPER; AS REAGENT FOR ANTIMONY, BISMUTH, COBALT, NIOBIUM, GOLD, MANGANESE, MERCURY, MOLYBDENUM, TANTALUM, THALLIUM, TUNGSTEN; AS BIOLOGICAL STAIN.
• RED DYE FOR WOOL & SILK WHERE BRILLIANT FLUORESCENT EFFECTS ARE DESIRED.
• Food Additives -> COLOUR -> JECFA Functional Classes

Synonyms

RHODAMINE B; 81-88-9; Basic Violet 10; Brilliant Pink B; Tetraethylrhodamine; Rhodamine B chloride; Calcozine Red BX; Symulex Magenta F; Rhodamine; Rhodamine O; Rheonine B; Rhodamine FB; Geranium lake N; Rhodamine BA; Rhodamine BF; Rhodamine BL

Frequently Asked Questions

What are the CAS number and molecular formula of Rhodamine B?

CAS 81-88-9; molecular formula C28H31N2O3.Cl; molecular weight — g/mol.

What other names is Rhodamine B known by?

RHODAMINE B, 81-88-9, Basic Violet 10, Brilliant Pink B, Tetraethylrhodamine, Rhodamine B chloride.

What is the regulatory status of Rhodamine B?

Documented regulatory listings: COLOUR: Food Additives; CI FOOD RED 15; NMRS 38/TRS 309-JECFA 8/24.

Is Rhodamine B classified as hazardous?

0.9% of GHS notifications report no hazard classification (22 of 2557).

What are the key physical properties of Rhodamine B?

Other Experimental Properties: 165 °C (anhydrous); Color Additive Status: 81.10; Color Additive Status: 81.30.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.