Nigrosines

The violet dyestuffs of magenta residues differ from the indulines in so far that they give a brown solution with sulphmde acid, while all the latter give a blue. 

Sulphonic acids of the indulines and nigrosines are also known. 

The sodium salts of the sulphonic acids of various indulines come into commerce under the names of Fast Blues, Blackley Blue, Indigo substitute, c. The diflerence of the various marks depends on the shade of the induline sulphonated and the number of sulpho-groups introduced. 

The indulines are mostly insoluble in water both in form of bases and salts, but are soluble in alcohol. The solutions of the bases are red to reddish violet, the salts are bluish violet, blue, or bluish grey. They are soluble in concentrated sulphuric acid with a pure blue colour, the sulpho-acids have the same colour as the salts of the original induline, and the salts of the sulpho-acids have the same colour as the free bases. 

The Indulines are destroyed on oxidation, quinone being formed reducing agents produce easily oxidisable leuco-compounds. 

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TuU Chemical Co. (Oxford, Alabama) is the only producer of sodium fluoroacetate. It is sometimes colored with the black dye nigrosine. It is usually packed in 8 oz (227 g) or 5 kg cans and is almost exclusively exported. There is very limited use in the United States. 

A smaller volume use of PAP is the production of dyestuffs and resins. Nigrosine dyes are widely used as black colorants in plastics, inks (qv), textiles, and shoe poHshes. 

Dyes in these classes are generally basic dyes ie, the chiomophoie is cationic. Some stmctures have been sulfonated to acid dyes, eg, the Nigrosine, (Cl Solvent Black 5 Cl 50415), (8) to Cl Acid Black 2 [8005-03-6] (Cl 50420) (9). 

Azine Dyes. Azine dyes (qv) include induline and nigrosines. They produce jet blacks unobtainable with carbon black. This was particularly tme of Induline Base in nylon before its manufacture was discontinued because of a carcinogenic impurity (4-aminobiphenyl). The nigrosines are used in ABS, polypropylene, and phenohcs. 

Numerous dyes structurally related to the safranines, such as the eurodines, e.g. (141), the indulines, e.g. (142), the nigrosines (143) and aniline black, a pigment of unknown structure used in the printing industry, are well known and a detailed account of their chemistry and applications has been presented (57HC(ll)l). 

Malachite green Metanil yellow Nigrosine Orange Y Paramido phenol Paraphenylendiamine Pyrogene violet brown Rosaniline Safranine... 

Nigrosine. A dye consisting of a mixt of aniline, aniline hydrochloride and nitrophenol, or nitrobenzene and Fe. It was used in Ballistite pro pints in 0.05—0.10% concn (see under Ballistite in Vol 2, B9-R)... 

The less important positive CCAs are metal-free cationic molecules, such as the black dye nigrosine and the colorless quaternary compound cetyl pyridinium chloride.35,36... 

Fig. 4. — Monitoring of the Multiple Molecular Forms of Tomato Pectinesterase by Starch-gel Electrophoresis.98 [ENZ, detection of pectinesterase activity by paper print with pectin and Bromothymol Blue PROT, protein staining with nigrosin O, origin. Key A, 1 crude tomato extract after ammonium sulfate salting-out, and dialysis 2 pectinesterase fraction from column of DEAE-Sephadex A-50 3 and 4 pectinesterase fractions from column of Sephadex G-75. B, Two parts of the same gel after horizontal slicing 1, 500 fig of the isolated form of pectinesterase from a column of CM-Seph-adex C-50 with 175 mM phosphate-sodium chloride buffer 2, active fraction at 150 mM buffer 4 and 5, 250 fig and 1 mg of the isolated form of pectinesterase, respectively.]...

Example with nigrosine paste and silver electrodes, a storage of 1.5 mAh/cm3 and, at a mean voltage of 0.9 V with a discharge time of about 11 min, a volumetric storage capacity of 1.3 mWh/cm3 were measured. The corresponding capacity of a lead starter battery is 11 mAh/cm3 or 15 mWh/cm3. 

The open-shutter method was used and the photolight had a duration of useful illumination of about 1 microsecond. The water cell contained a solution of nigrosin... 

In Ref 23 is given the compn of Ballistite JP, which is practically the same as for JP 204 except that JP apparently does-not contain methyl-cellulose but does contain 0.1% nigrosine dye... 

Addnl Ref L.Pauling et al, OSRD Rept 3783 (1944)(Ballistitesof approx compn NC 52, NG 43, K nitrate 1.5, DEtPh 3.0 DPhA 0.5% exhibited better thermal stability with added carbon black, ca 0.1%, than with Nigrosine dye. These substances serve as opacifying agents)... 

Assess cell viability using nigrosin exclusion (see Note 18). 

Nigrosin, dissolved to a final concentration of 0.1% w/v in phosphate-buffered saline containing 2% FBS, filter-sterilized, and stored at 4°C (BDH, Merck, Poole, Dorset, UK). 

Calculate the cell density by diluting 10 pL of suspension in 90 pL of nigrosin then count the cells using a haemocytometer. Adjust the density to 5 x 105 cells/mL in production medium and inoculate the reactor with 35 mL of this suspension using the following procedure (see Note 12). 

Polyamines as Coupling Components. Chrysoidines are obtained by coupling dia-zonium salts of aniline, toluidines, or mixtures thereof to polyamine coupling components such as 1,3-phenylenediamine, 2,4- or 2,6- toluylenediamine, or mixtures of these diamines. These dyes confer muted yellow to orange shades to paper, leather, and polyacrylonitrile fibers. When they are mixed with malachite green and fuchsin, medium-fast black shades are obtained on polyacrylonitriles. A mixture of chrysoidine with Crystal Violet or Victoria Pure Blue is used to adjust the color of nigrosine hectograph inks [1]. 

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