Eosin ether

EbuUioscopic method, 37 Electrolytic reduction, oxalic acid, 102 nitrobenzene, 144, 145 Eosin, 187 Epichlorhydrin, in Estimation of carbon and hydrogen, 4 halogens, 22 nitrogen, 13 sulphur, 28 Ether, 59... 

Rose Bengal differs in reactivity from fluorescein and Eosin because of the iodines at C-2, C-4, C-5, and C-7 which differentiate the reactivity of the phenoxide from the carboxylate and make substitution at C-2 possible in lieu of substitution at C-6. Essentially three different kinds of Rose Bengal derivatives have been synthesized. The most common include derivatives with gegen ions other than sodium at both C-2 and C-6. Many esters of C-2 have been synthesized and compounds with a number of different gegen ions at C-6 have been reported. The rarest derivatives of Rose Bengal are the C-6 ethers, of which only three have been reported. 

Eosin is detected by treating the carmine with dilute sulphuric acid, shaking with ether and evaporating the ethereal solution the eosin may then be identified in the residue. 

Some colouring matters containing chlorine, such as eosin, may leave ash containing haloid salts. In this case the solution of the colouring matter, addified with sulphuric acid, may be extracted with ether and the aqueous liquid tested for chlorine and sodium. 

By treating the potassium salt of eosin with methyl iodide or chloride, or with ethyl bromide, monomethyl- and monoethyl-ethers of eosin may be obtained, and these even surpass the eosins in brilliancy of shade, their tone being in general somewhat bluer. 

The ethyl ether, in form of its sodium or potassium salt, is extensively used in silk-dyeing as spirit eosin or primerose h kalcool/ For use, the commercial product is dissolved in spirit and gradually added to the dye-bath, which is acidified with acetic acid. 

Colourless ethers of eosin also exist, and may he prepared by heating the silver salt of eosin with alcoholic iodides [63],... 

Chloro-l-hydroxynaphthalene is converted into the sulphonate 246 on eosin-sensitized irradiation in the presence of sodium sulphite. A study of the chain substitution of the chloro group in 4-chloro-l-hydroxynaphthalene by aqueous sodium sulphite has shown that two mechanisms for the photoinitiation have been identified and two intermediates have been detected a radical anion of 4-chloro-l-naphthoxide and the sulphite radical anion. Thus, an SjjajI mechanism is suggested and is one that involves reaction with the radical anion of sulphite. An example of the S n 1 process between a phenol and the (2-cyanoaryl)azo-f-butylsulphides has been reported. The 1 reactivity of several compounds (Scheme 27) have demonstrated that 247 is a product however, this is also photochemically reactive and is converted into the cyclic ether 248 . 

Copper can be determined by use of ion associates, formed by the cationic complexes of Cu(I) with cuproine [63-65], neocuproine [65], bathocuproine [66] and thio-crown ethers [67,68], associated with the acid dyes such as Rose Bengal (e = 7.8-10 ) [63,65,66], the ethyl ester of eosin (e = 9.4-10 ) [64], and Erythrosin [63]. These ion-associates are extracted into chloroform [65,66], 1,2-dichloroethane [64,67,68], and other solvents. The ion-associates of cyanide [69] and chloride [70,71] complexes of Cu(I) with Methylene Blue (1,2-dichloroethane, = 9.8-10 ) [69], and Ethyl Violet (toluene, = 9.6-10 ) [70] are also worth mentioning. The halide complexes of Cu(I) with azo dyes have also been extracted. 

The cationic complex of silver and 1,10-phenanthroline (phen) has been found to react with Bromopyrogallol Red to yield an ion-associate which can be extracted into nitrobenzene (e = 3.2T0" at 590 nm) [31,32]. The cationic complex, Ag(phen)2 gives ion-associates also with acid dyes, such as Rose Bengal (formula 4.35) and eosin (formula 4.34) (nitrobenzene) [33]. Extractable ion-associates of cationic silver complex with 1,4,8,11-tetrathiacyclotetradecane (crown ether), and various chromogenic anions [34] should also be mentioned. 

A more recent example by Balzani and Vbgtle provided an additional chro-mophore for cascade energy transfer [115]. Poly(aryl ether) dendrons with naphthyl groups at the periphery were attached to the sulfonamides of the second generation dansyl terminated dendrimers to create a super dendrimer 86 consisting of three different types of chromophores 32 naphthyls, 24 alkoxybenzenes, and 8 dansyls (Scheme 44). When eosin is extracted into... 

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. 

Eosin Y. See Acid red 87 Eosin YS. See D C Red No. 22 Acid red 87 EOTMPTA. SeeTrimethylolpropane ethoxytriacrylate EP 2220 TC. See Epoxy resin EP. See p-Ethylphenol Propylene glycol ethyl ether... 

A wide assortment of additional electron-transfer PSs for diaryliodonium salts have been described in the journal and patent literature. These include ketocoumarins [FOU 88], 9,10-phenanthraquinone [BAU 86], Mannich bases [DE 88b], 1,3-indanediones [TEH 13], benzoquinonylsulfanyl derivatives [SUG 03], acridinediones [SEE 01] and dimethylaminobenzylidine derivatives [ICH 87], In addition, the use of dyes such as eosine and Rhodamine [DE 88a, DE 89] have been employed to provide photosensitization in the visible region of the spectrum. A particularly interesting system devised by Yagci et al. [AYD 08] is the dithienothiophene, 48, used with diphenyliodonium hexaflurophosphate to carry out the cationic photopolymerizations of cyclohexene oxide, 3,4-epoxycyclohexylmethyl 3, 4 -epoxycyclohexane carboxylate, N-vinyl carbazole, n-butyl vinyl ether and styrene. These investigators have further applied this system to the preparation of metallic silver-filled epoxy nanocomposites [YAG 11]. 

Eosine YS 9713 1-Ethoxyhexane 5061 Ethylene glycol monobenzyl ether 817... 

Karatsu and co-workers recently reported that, Hke the corresponding oxime O-methyl ether and imine, a 2-anthryl group attached to an azo group appreciably influenced the Z E ratio, rich in the E-isomer, at the photostationary state 2-phenylazoanthracene in an EPA matrix in the presence of eosin as a triplet sensitizer upon irradiation at 273K with 520-nm light resulted in a 9 1 E Z-mixture of the... 

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