Tetrabromo fluorescein

POPAM dendrimers bearing up to 32 photoswitchable azobenzene groups at the periphery were used as host compounds for eosin Y (2, 4, 5, 7 -tetrabromo-fluorescein dianion) (see also Section 5.1.2). One reason for the choice of this dye was that it shows strong fluorescence which should be influenced by being enveloped by the dendrimer. The other reason was that the energy of its lowest triplet state is higher than that of the lowest triplet state of azobenzene, leading... 

B4. Balkisson, B., Sheltun, T. G., and Spellman, M. W., The rapid determination of plasma volume with simultaneous estimation of excretory liver function in patients by the rose bengal dye (tetraiodo tetrabromo fluorescein) method. Ann. Svrg.tVt, 505-514 (1958). 

Beilstein Handbook Reference) acid eosin BRN 0063410 Bromeosin Bromoeosin C.l. 45380 2 C.l. Solvent Red 43 CCRIS 4904 Cl 45380 2 D C Red no. 21 D and C Red No. 21 D C Red No. 21 2-(3,6-Dihydroxy-2,4,5,7-tetrabromoxanthen-9-yl)-benzoic acid 3,6-Dihydroxy-2,4,5,7-tetrabromospiro-(xanthene-9,3 -phthalide) EINECS 239-138-3 Eosin Eosin A Eosin acid Eosin 3J Eosin 4J extra Eosin A extra Eosin B Eosin C Eosin DH Eosin G Eosin G Extra Eosin GGF Eosin JJS Eosin KS Eosin yellowish Eosin Y spirit soluble Eosine acid Fluorescein, 2, 4, 5 ,7 -tetrabromo- Japan Red 223 Japan Red No. 223 NSC 244436 Red No. 223 Solvent Red 43 Spira(isobenzofuran-1(3H),9 -(9H)-xanthen)-3-one, 2, 4, 5, 7 -tetrabromo-3 ,6 -di-hydroxy- Water soluble eosin. The alkali salts of tetrabromo-fluoresceine, dyes wool and silk yellowish red used as a microscopic stain and a fluorescent tracer dye red writing ink cosmetic products and a colorant for motor fuel. Red solid. 

A number of derivatives of fluorescein are useful dyes. Uranin is the disodium salt of fluorescein. ChrysoUn is a salt of benzyl-fluorescein, which is formed from phthalic anhydride and benzyl-resorcinol. It dyes silk and wool a fast yellow, and is used in cotton dyeing. Eosin is the disodium salt of tetrabromo-fluorescein, which is prepared by the action of bromine on fluorescein. Its dilute alkaline solution is rose-colored, and exhibits an intense yellow-green fluorescence. Other dyes related to fluorescein are tetrabromo-dichlorofluorescein and various ethers of fluorescein and its substitution-products. The dyes of this class produce on silk and wool shades from yellow to reddish yellow, cherry-red, and purple. 

PEGs can be used in hpsticks as solubilizers for tetrabromo-fluorescein and its derivatives. According to Nowak (95), the solubility in PEG 400 is about 10%. Higher additions of PEG should be avoided because of their good solubility in water, since dyes then tend to bleed. 

The basis of this method is that when normal seawater is chlorinated at the usual levels of 1 to 10mg/l of chloride, the bromine in seawater (8.1 x 10 4 M, 65 mg/1 at salinity = 35%o) is rapidly and quantitatively oxidised to Br() and HBrO. If 50 mg/1 of bromide is added to distilled or fresh waters containing HCIO plus C1CT, then HBrO plus BrO" are both formed. The HBrO plus BrO" will in turn rapidly brominate fluorecein (9-[o-carboxyphenyl]-6-hydroxy-3-isoxanthenone) to give the pink tetrabromo derivative eosin yellow (2,4,5,7-tetrabromo-9-[o-carboxyphenyl]-6-hydroxy-3-isoxanthenone), provided the molar ratio of bromide to fluorescein is 4 1. The resultant increase in eosin can be measured visually or spectrophotometrically, and the decrease in fluo-roscein measured fluorometrically. If the molar ratio of bromide to fluoroscein is < 4 1, then the mono-, di-, and tri-bromo derivatives are formed repro-ducibly. These derivatives have extinction coefficients close to eosin and are accounted for in the standardisation. 

Brominating fluorescein in the presence of sodium chlorate affords the red tetrabromo derivative, whose sodium salt is known as eosine (Caro 1871). Sodium chlorate reoxidizes, evolving hydrogen bromide, to bromine which can react again ... 

Reaoroin-phthalein—FluoreKHn——bears the same relation to resorcin that phenol-phtbalein does to phenol, and is obtained from resorcin by a corresponding method. It is a dark-brown ciystallins powder, which dissolves in ammonia to form a red solution, exhibiting the most brilliant greeu fluorescence. A tetrabromo-derivative of fluorescein is used as a dye under the name eorin. 

Fluorescein, 2, 4, 5, 7 -tetrabromo-4,5,6,7-tetrachloro-, disodium salt. See Acid red 92 Fluorescein, 2, 4, 5, 7 -tetraiodo-, disodium salt. See Acid red 51... 

Paucescu, S. D. lonescu-Ioan, C. Microscopy xanthine dyes. II. Fluorescein bromination to tetrabromo compounds. Rev. Chim. 1980, 31,339—341 Chem Abstr. 1980,93, 96775. 

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