Violet, Acid

Acid rhodamines are made by the iatroduction of the sulfonic acid group to the aminoxanthene base. The preferred route is the reaction fluorescein (2) with phosphorous pentachloride to give 3,6-dichlorofluoran (fluorescein dichloride) (23), which is then condensed with a primary aromatic amine in the presence of 2inc chloride and quicklime. This product is then sulfonated. For example, if compound (23) (fluorescein dichloride) is condensed with aniline and the product is sulfonated. Acid Violet 30 Cl45186) (24) is produced. 

In 1894 the first two anthraquinone acid dyes. Cl Acid Violet 43 [4430-18-6] (2) (Cl 60730) and Cl Acid Green 25 [4403-90-1] (3) (Cl 61570) were invented. This encouraged the subsequent development of various kinds of anthraquinone acid dyes, which were used to dye wool in fast, brilliant shades without need for pretreatment. 

Cl Acid Gieen 25 [4403-90-1] (3) (Cl 61570) was also invented in 1894. This dye shows improved wetfastness, and is prepared from leucoquinizarin by reaction with 2 moles of i)-toluidine in a similat manner to the preparation of Cl Acid Violet 43 (134). Wetfastness and leveling properties may be altered by choosing the substituents of arylamines. The introduction of alkyl groups into aromatic amines improves the wetfastness and affinity in neutral or weekly acid baths. Examples ate Cl Acid Blue 80 [4474-24-27] (131) (Cl 61585) and Cl Acid Gieen 27 [6408-57-7] (132) (Cl 61580). 

The most important 2 1 metal complex azo dyes are the 2 1 Cr3+ dyes. These may be symmetrical dyes, such as the water-soluble dye Cl Reactive Brown 10 (28), and the solvent-soluble dye Cl Solvent Yellow 21 (29), used in varnishes as a wood stain. They may also be unsymmetrical complexes, such as Cl Acid Violet 121 (30), used for dyeing wool and nylon. 

Pseudomonas putida mt-2 Acid Violet 7 Complete biodegradation of azo dye up to 200 mg L 1 was achieved in 49 h under shaking while the biodegradation time was reduced to 37 h under static conditions [81]... 

Ben-Mansour H, Mosrati R, Corroler D et al (2009) In vitro mutagenicity of Acid Violet 7 and its degradation products by Pseudomonas putida mt-2 correlation with chemical structures. Env Toxicol Phamacol 27 231-236... 

Pseudomonas st.s Acid violet 7 Acid red 151 Reactive black 5 Acid yellow 34 Flask Batch... 

Acid Violet 7 T. versicolor Activated carbon powder [49]... 

Complex mycelium pellets of Trametes versicolor with activated carbon powder were investigated for decolorization of Acid Violet 7 [49]. The complex pellets showed the best dye removal. The dye was almost completely removed in 6 h. For complex pellets, maximum decolorization rate (Vmax mg/L h) and half velocity concentration (Ks mg/L) was calculated 130.5 and 345.0 in batch system, respectively. 

Zhang FM, Yu J (2000) Decolourisation of acid violet 7 with complex pellets of white rot fungus and activated carbon. Bioprocess Eng 23 295-301... 

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. 

A suitable example is Cl Acid Blue 27 (6.37 X = NHCH3), which is made from 4-bromo-l-methylaminoanthraquinone by nucleophilic displacement followed by sulphonation. Some commercial acid dyes based on 1,4-diaminoanthraquinone contain substituents in both the 2- and the 3-positions. Thus, for example, Cl Acid Violet 41 (6.38) is produced by the condensation of l,4-diamino-2,3-dichloroanthraquinone with phenol in the presence of sodium sulphite and manganese dioxide. 

Aminohydroxyanthraquinone derivatives are available from leucoquinizarin by heating with an appropriate arylamine and boric acid in aqueous ethanol, followed by oxidation. The use of p-toluidine and subsequent sulphonation gives Cl Acid Violet 43 (6.37 X = OH). 

Crystal violet (0.5% w/v in glacial acetic acid) Violet Blue-green Yellowish green... 

Thus, RP-HPLC-MS has been employed for the analysis of sulphonated dyes and intermediates. Dyes included in the investigation were Acid yellow 36, Acid blue 40, Acid violet 7, Direct yellow 28, Direct blue 106, Acid yellow 23, Direct green 28, Direct red 79, Direct blue 78 and some metal complex dyes such as Acid orange 142, Acid red 357, Acid Violet 90, Acid yellow 194 and Acid brown 355. RP-HPLC was realized in an ODS column (150 X 3 mm i.d. particle size 7 /.an). The composition of the mobile phase varied according to the chemical structure of the analytes to be separated. For the majority of cases the mobile phase consisted of methanol-5 mM aqueous ammonium acetate (10 90, v/v). Subsituted anthraquinones were separated in similar mobile phases containing 40 per cent methanol. The flow rate was 1 ml/min for UV and 0.6 ml/min for MS detection, respectively. The chemical structure of dye intermediates investigated in this study and their retention times are compiled in Table 3.28. It was found that the method is suitable for the separation of decomposition products and intermediates of dyes but the separation of the original dye molecules was not adequate in this RP-HPLC system [162],... 

Acid violet 5 35% methanol 40% methanol for 20 min and linear gradient to 50% methanol at 30 min and kept at 50% methanol... 

C. J. Tredwell and A. D. Osborne, Viscosity dependent internal conversion in the rhodamine dye, fast acid violet 2R, J. Chem. Soc. Faraday Trans. II 76, 1627 (1980). 

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