Diazo violet

Water as the solvent. Water may be used to dissolve tropeolin 00, methyl orange, p-nitrophenol, sodium alizarine sulfonate, propyl-a-naphthol orange, nile blue, alizarine yellow, diazo violet, and tropeolin 0. 

Diazo violet o-p-Dihydroxy-azo-p-nitrobenzene 10.1-12.0 yellow - violet Kolthoff... 

In contrast to direct dyes, metal-complex azo reactive dyes are almost always monoazo chromogens coordinated to one copper(II) ion per molecule. The important structural types include phenylazo J acid reds (5.47), phenylazo H acid violets (5.48) and naphthylazo H acid blues (5.49), where Z represents the reactive system attached through the imino group in the coupling component. Less often the reactive system is located on the diazo component, as in Cl Reactive Violet 5 (5.50) and analogous red to blue members of various ranges. 

Violets and heliotropes of the benzo, benzoform, bnlliant Congo, chloramine, chlorazol, Columbia, diamme, diaml, dianol, diazo, diphenyl, direct, formal, naphthamine, oxamme, oxydiamme, para, rosantbrene, tnsulphon, etc, senes Azo marne, azo violet, benzo fast heliotrope, chlorantme lilac, hessian purple V-olet ... 

In addition, the following have been described as diazo components 2,5-dichloro-4-nitroaniline (red) [49], 2-chloro-5-trifluoromethylaniline (yellow) [50], 4-nitro-2-trifluoromethylaniline (red) [51], 2-amino-5-trifluoromethyl-l,3,4-thia-diazole (red) [52], 3-methylmercapto-5-amino-l,2,4-thiadiazole (red) [53], 3-methyl-4-nitro-5-aminoisothiazole (blue-violet) [54], 2-amino-6-chlorobenzothia-zole (red) [55], and 3-amino-5-nitro-7-bromobenzisothiazole (blue with a red cast) [56],... 

Through the choice of suitably substituted diazo components, bluish red to blue wool dyes with good light- and wetfastnesses can be produced, e.g., C.I. Acid Violet 14, 17080 (7) [4404-39-1],... 

Nitro-4 toluidine (15.2 grams) is diazotized by the procedure given on page 246. Ice is added to the filtered diazo solution to lower the temperature to 2-5°C. The solution is then neutralized with sodium acetate to the point where Congo red paper is just turned violet. 

The dyes from diazo-compounds of the benzene series (Pon-ceaux R, RR, RRR, and Coccinines) form scarlet powders, which dissolve in strong sulphuric acid with a red colour. They give crystalline calcium salts which are soluble in hot water. Dyestuffs containing naphthalene rests on both sides dissolve in sulphuric acid with blue or violet colour. 

From /8-naphthol-a-monosulphonic acid [48] and o-diazo-naphthalenesulphonic acid. Is a beautiful scarlet dyestuff which dissolves in sulphuric acid with a reddish-violet colour. 

To a deep red-violet colored solution containing 1-phenyldiazoethane (5.5 g, 0.042 mol) was added a solution of methyl ( )-3-aryl-2-cyanoacrylate (0.03 mol) in CH2CI2 (25 mL) at — 5 to 0°C. The deep color of the diazo compound disappeared gradually and became light yellow. After the mixture stood overnight at rt, the solvent was evaporated under reduced pressure (20-25 Torr) at 40-50"C, and 12-15 g of crude product was obtained. The products were separated by chromatography on silica gel with a mixture of CHCI3 and CC as eluant. The isolated products that were solids were recrystallized from 95% EtOH or from benzene. Other similar examples are compiled in Table 4. 

Sorensen states that the triphenylmethane dyes also show a pronounced salt error. However, metanil yellow extra (diazo-sulfonic acid indicator) is serviceable. Sorensen examined three 0.01 N hydrochloric acid solutions with methyl violet, mauveine, methyl green, and metanil yellow extra. Solution A contained only acid, B contained in addition 0.1 N KCl, whereas C was 0.3 N with respect to this salt. The pH s measured colorimetrically with each of these four indicators are compared with those determined electrometrically and with the values calculated from the nature of the three solutions. These findings are summarized in the following table. 

Fig. 17.1. Protein patterns of different potato cultivars obtained by isoelectric focussing on polyacrylamide gel pH 3-10. a Protein bands stained with Coomassie Blue b Staining of trypsin and chymotrypsin inhibitors (Tl, CH) Incubation with trypsin or chymotrypsin, N-acetylphenylalanine-P-iraphthyl ester and diazo blue B inhibitor zones appear white on a red-violet background, (according to Kaiser, Bruhn and Belitz, 1974)...

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