Yellow, Alizarin Brilliant

The applicability of the supramolecular approach for SRG recording has been demonstrated by combination of different charged azobenzene derivatives with different polyelectrolytes. Such azobenzene derivatives as Brilliant Yellow, Alizarin Yellow GG, and Methyl Red, all commercially available, have been used as active components. The chemical structures of the compounds are shown in Fig. 2.7. Note that the absorption may be tuned by a proper selection of the dye component that can match specific applications where given laser wavelengths must be used. 

Alizarin Alizarin Red S Alizarin Yellow R Benzopurpurine 4B 4,4 -Bis(2-amino-l-naphthylazo)-2,2 -stilbenedisulfonic acid 4,4 -Bis(4-amino-l-naphthylazo)-2,2 -stilbenedisulfonic acid Brilliant Yellow Bromocresol Green Bromocresol Purple Bromophenol Blue Bromothymol Blue Chlorophenol Red Clayton Yellow Congo Red o-Cresolphthalein Cresol Red Crystal Violet Curcumin (Turmaric) p-(2,4-Dihydroxyphenylazo) benzenesulfonic acid, sodium salt... 

When alizarin S is used as reagent, the sensitivity may be considerably increased by viewing the reaction picture in ultraviolet light. The solution of alizarin S in concentrated sulfuric acid is yellow in ultraviolet light, and is changed to brilliant red by boric acid Idn, Limit 0.02 y boron). The interferences due to colored ions and Be+ ions are obviated if the fluorescence colors are observed. 

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