Anthraquinone sulphonates

Sodium anthraquinone- -sulphonate ( silver salt ). Place 60 g. of fuming sulphuric acid (40-50 per cent. SOj) in a 250 or 500 ml. round-bottomed flask and add 50 g. of dry, finely-powdered anthraquinone (Section IV, 145). Fit an air condenser to the flask and heat the mixture slowly in an oil bath, with occasional shaking, so that at the end of 1 hour the temperature has reached 160°. Allow to cool and pour the warm mixture carefully into a 2 htre beaker containing 500 g. of crushed ice. Boil for about 15 minutes and filter off the unchanged anthraquinone at the pump. Neutrahse the hot filtrate with sodium hydroxide and allow to cool, when the greater part of the sodium anthraquinone- -sulphonate separates as silvery glistening plates ( silver salt ). Filter these with suction and dry upon filter paper or upon a porous plate. A second crop of crystals may be isolated by concentration of the fitrate to half the original volume. The yield is 40-45 g. 

A mixture of 2 g. of potassium chlorate, 30 g. of commercial sodium hydroxide, 10 g. of finely powdered sodium /3-anthraquinone-sulphonate ( silver salt ), and 40 c.c. of water is heated for twenty hours at 170° (oil bath) in an autoclave or in an iron tube with screwed-on cap. The cooled melt is repeatedly extracted with hot water and the extracts, after being combined and filtered, are acidified while hot with excess of hydrochloric acid, which precipitates the alizarin. When the mixture has cooled the precipitate is collected at the pump, washed successively with dilute hydrochloric acid and water, and dried. 

Fig. 3.130. HPLC chromatograms of the test mixture detected by DAD (270 nm, upper lane) by APCI-MS-TIC (middle) and by ESI-MS-TIC (lower lane). Peak identification l=benzene sulphonic acid sodium salt 2=2-naphtalene sulphonic acid sodium salt 3=2-anthraquinone sulphonic acid sodium salt 4 = sulphorhodamine D sodium salt 5=crocein orange G 6=eriochrome black T 7=2,6-anthraquinone disulphonic acid disodium salt 8 = 1,5-naphtalene disulphonic acid disodium salt 9 = azophloxine 10 = 1,2-benzene disulphonic acid dipotassium salt. Reprinted with permission from G. Socher et al. [178].

As an example, the polymerization of vinyl monomers by anthraquinone sulphonates (AS) in the presence of reducing agents [72] is presented. 

CT complexes are formed and electron transfer occurs from excited molecules of anthracene derivatives to methylviologen in aqueous micellar media. Methylene blue quenches pyrene fluorescence by electron transfer in SDS micelles . E.lectron transfer between anthraquinone sulphonate radicals and duroquinone in SDS micellar solution occurs in the aqueous phase there is no evidence of intramicellar transfer. Photoionisation of... 

Alizarin, the dyestuff contained in madder, is made from anthracene, another coal tar product, by the action of "sodium bichromate and sulphuric acid to form antbraquinone this is traniSformed by the action of sulphuric acid into anthraquinone sulphonic acid, the sodium salt of which when fused with soda and a little potassium chlorate yields a compound of alizarin containing sodium, from which alizarin itself is made by the action of acid. 

Skuratova 97 has put forward an alternative mechanism for the primary step in the extensively studied photochemical reduction and hydroxylation of anthraquinone sulphonates. In distinction to the conventionally accepted mechanism it is proposed that hydroxyl radicals are involved. 

Irradiation of sodium anthraquinone sulphonates in micelles leads to photoreduction to the corresponding radical anions, whose lifetimes are much lengthened compared with those obtained in the absence of surfactants.31 It is reported that photoreduction of anthraquinone sulphonates in basic water-alcohol solutions can lead on to desulphonation of the 9,10-dihydroxyanthracenes which are produced.32 Photoreduction of sodium l,2-naphthoquinone-4-sulphonate in water gives the 1,2-dihydroxy-compound.33 In this reaction,... 

Alizarin is reduced to anthracene when heated with zinc-dust—a transformation which was the first step taken in determining the structure of the dye contained in madder-root. The view that alizarin is a dihydroxyl derivative of anthraquinone, follows from the fact that it is formed as the result of the fusion of anthraquinone-sulphonic acid with caustic alkalies, and from the synthesis of the dye by heating phthalic anhydride and pyro-catechol with sulphuric acid at 150° —... 

Mayer [12] has discussed a very interesting case from our studies [32] involving anthraquinone sulphonates (mono- and di-), where the mono-sulphonate showed an increase in the value of log K q for the reaction (23) on either side of pH of about 8.5, while the di-sulphonates showed a continuous drop in log K q with pH, ending in a plateau at pH 14. These observations could also be explained on the basis of the redox characteristics. 

ABSTRACT. The complex formation between cyclodextrins (a-,3-,y-CD s and dimethyl-3-CD) and quinones (three 9,10-anthraquinone sulphonates and two 1,4-naphthoquinones) in the water-ethylene glycol 1 1 mixture solution at 77 K was investigated using the n7T phosphorescence spectra and their excitation spectra and lifetimes of the quinones. It was concluded on the basis of the experimental results that the complexes have various structures according to the CD-quinone combination used. Vitamin K3 was found to form the photodimer very effi-... 

Anthraquinone sulphonic acid C6H4(CO)2CeH3S03H, an intermediate in the synthesis of dyestuffs in solution, has no action on aluminium, even at elevated temperatures. 

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