Triphenylmethane colorants

Synonyms Acid blue 3, calcium salt (2 1) Cl 42051 N-[4-[[4-(Diethylamino) phenyl] (5-hydroxy-2,4-disulfophenyl) methylene]-2,5-cyclohexadien-1 -ylidene]-N-ethylethanaminium, hydroxide, inner salt, calcium salt (2 1) Ethanaminium, N-[4-[[4-(diethylamino) phenyl] (5-hydroxy-2,4-disulfophenyl) methylene]-2,5-cyclohexadien-1-ylidene]-N-ethyl-, hydroxide, inner salt, calcium salt (2 1) Food blue 5 m-HydroxytetraethyIdiaminotriphenylcarbinol anhydride disulfonic acid calcium salt Patent blue Patent blue V Patent blue violet Ciassification Triphenylmethane color Empiricai Cs4H62CaN40i4S4 Properties M.w. 1159.52 Toxicoiogy LD50 (IV, rat) 5 g/kg, (IV, mouse) 1200 mg/kg mod. toxic by IV route TSCA listed Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of NOx and SOx Uses Dye for wool colorant in foods, hair dyes Manuf./Disthb. AB R Lundberg Dudley... 

Classification Triphenylmethane color Empirical C37H34N2O9S3 2Na Properties Greenish-blue powd., gran. sol. (oz/gal) 52 oz propylene glycol, 36 oz glycerin, 25 oz dist. water, 2 oz 95% ethanol sol. in ether, cone, sulfuric acid pract. insol. in veg. oils m.w. 792.86 m.p. 283 C (dec.)... 

Classification Azobenzene triphenylmethane color Empirical C33H40CIN3 Properties M.w. 514.15 Toxicology TSCA listed Uses Dye for paper pigment in printing inks solvent dye for ballpen inks, printer ribbons colorant in hair dyes... 

Victoria blue Victoria blue B Classification Triphenylmethane color Empirical C33H32N3 Cl... 

Ciassification Azobenzene triphenylmethane color Empihcai C20H20CIN3... 

Classification Triphenylmethane color Definition Ammonium salt of FD C Blue No. 1 Empirical C37H42N4O9S3 Formula C37H36N2O9S3 2H3N Properties M.w. 783.01... 

Hydroxy-2-Naphthalenecarboxylic Acid. l-Hydroxy-2-naphthoic acid is made similarly to the isomer (2-hydroxy-1-naphthoic acid) by reaction of dry sodium 1-naphthalenolate with CO2 in an autoclave at ca 125°C. It has been used in making triphenylmethane dyes and metalli able a2o dyes. Alkylamides and arylamides of l-hydroxy-2-naphthalenecarboxyhc acid are cyan couplers, ie, components used in indoaniline dye formation in color films (see Color PHOTOGRAPHY). 

The mechanism of reaction with steroids has not been elucidated. Various nonquantitative reactions occur simultaneously. Cyclopentenyl cations have been postulated as intermediates which condense with anisaldehyde to yield colored compounds [4]. It is probable that triphenylmethane dyes are also formed with aromatic compounds. 

Methylsulfinyl carbanion (dimsyl ion) is prepared from 0.10 mole of sodium hydride in 50 ml of dimethyl sulfoxide under a nitrogen atmosphere as described in Chapter 10, Section III. The solution is diluted by the addition of 50 ml of dry THF and a small amount (1-10 mg) of triphenylmethane is added to act as an indicator. (The red color produced by triphenylmethyl carbanion is discharged when the dimsylsodium is consumed.) Acetylene (purified as described in Chapter 14, Section I) is introduced into the system with stirring through a gas inlet tube until the formation of sodium acetylide is complete, as indicated by disappearance of the red color. The gas inlet tube is replaced by a dropping funnel and a solution of 0.10 mole of the substrate in 20 ml of dry THF is added with stirring at room temperature over a period of about 1 hour. In the case of ethynylation of carbonyl compounds (given below), the solution is then cautiously treated with 6 g (0.11 mole) of ammonium chloride. The reaction mixture is then diluted with 500 ml of water, and the aqueous solution is extracted three times with 150-ml portions of ether. The ether solution is dried (sodium sulfate), the ether is removed (rotary evaporator), and the residue is fractionally distilled under reduced pressure to yield the ethynyl alcohol. 

Primary alcohols can be selectively detected using reagent sequences involving an initial oxidation to yield aldehydes that are then reacted in acid medium with electron-rich aromatics or heteroaromatics, according to the above scheme, to yield intensely colored triphenylmethane dyes. 

Classical examples of this type of reaction are the various dimethylaminobenz-aldehyde reagents (q.v.) and vanillin-acid reagents, of which one, the vanillin-phosphoric acid reagent, is already included in Volume 1 a. The aldol condensation of estrogens is an example for the reaction mechanism (cf. Chapter 2, Table 6). According to Maiowan indole derivatives react in a similar manner [1]. Longo has postulated that catechins yield intensely colored triphenylmethane dyes [2]. 

The general aspects of the aldehyde-acid reaction were discussed in Chapter 2. Thus it is readily understood that catechins, for example, can react with aromatic aldehydes in the presence of strong acids to yield colored triphenylmethane dyes [26]. 

Mechanisms depending on carbanionic propagating centers for these polymerizations are indicated by various pieces of evidence (1) the nature of the catalysts which are effective, (2) the intense colors that often develop during polymerization, (3) the prompt cessation of sodium-catalyzed polymerization upon the introduction of carbon dioxide and the failure of -butylcatechol to cause inhibition, (4) the conversion of triphenylmethane to triphenylmethylsodium in the zone of polymerization of isoprene under the influence of metallic sodium, (5) the structures of the diene polymers obtained (see Chap. VI), which differ. both from the radical and the cationic polymers, and (6)... 

Triphenylmethane dyes show inferior lightfastness properties. They are, however, still one of the most important groups of synthetic dyes due to their brilliance, high tinctorial strength, and low cost. Several reviews have appeared on di- and triphenylmethane dyes.1-5 However, the color-forming precursors — leuco dyes — have received less attention in the literature. 

Anodic oxidation has been employed for water-soluble triphenyl-methane dyes. It has been shown that the formation of dye is an irreversible two-electron oxidation process.21-23 This method has been used for the oxidation of diamino triphenylmethane leuco compounds containing two to four sulfonic acid groups to obtain food-grade colored materials.24... 

The formation of color from triheteroarylmethanes differs from the methodology employed for triphenylmethane leuco dyes40 (Scheme 4). Dyes are initially formed by alkylation of the pyridyl nitrogen, followed by deprotonation at the central methine carbon. Thus, treatment of the colorless 3,3 -diindolyl-4-pyridylmethane 22 with excess methyl iodide produces colorless compound 23. Subsequent treatment of 23 with hydroxide... 

Pressure-sensitive recording materials are obtained by dissolving a triphenylmethane leuco dye in a solvent composed of paraffin oils. The microcapsules are formed from a water-soluble106 or water-dispersible material.107,108 Leuco dyes dissolved in sunflower oil are microencapsulated in a solution containing a melamine-HCHO precondensate and coated on the back side of a paper sheet. Contact of the microcapsule-coated sheet with an acid-coated receptor sheet allows the color formation to occur. 

Derivatives of triphenylmethane were among the earliest synthetic colorants, and are still in demand where bright, intense colours are needed without the necessity for outstanding fastness to light and chemical reagents. Basic dyes of this type, as well as other cationic dyes, are suitable for dyeing conventional acrylic fibres, on which they show better fastness properties than on natural fibres. The photodegradation of triphenylmethane dyes has been reviewed [42]. 

Nonchelating dyes include basic triphenylmethane dyes (e.g., Brilliant Green, Malachite Green, Crystal Violet), xanthene dyes (e.g., Rhodamine B, Rhodamine 6G), azine dyes (e.g., Methylene Blue), and acid dyes (e.g., Eosin, Erythrosin). These are intensely colored and when paired with an oppositely charged analyte ion lead to high sensitivities. 

Triarylmethane dyes are derivatives of triphenylmethane and diphenylnaphthylmethane. The presence of one or more primary, secondary, or tertiary amino or -OH groups in the para position to the methane carbon determines the dye color. Halogen, carboxyl, or sulfonic acid substituents also may be present on the aromatic rings. Triarylmethane colorant applications include basic, acid, solvent, and mordant dyes. Major uses are in printing inks. 

Introduction of an oxygen bridge into the triphenylmethane dye molecule leads to the xanthene dyes. The color is shifted from blue to red. The restricted rotation of the phenyl groups inhibits radiationless de-excitation and gives rise to very strong fluorescence. Rhodamine B (14) is used for dyeing paper [11] and as a laser dye. 

Standard cyan ink-jet dyes are C.I. Acid Blue 9, 42090 [3844-45-9] and C.I. DirectBlue 199, 74190 [12222-04-7], C.I. Acid Blue 9 is characterized by a superior brilliancy of shade and high color strength, but this triphenylmethane dye exhibits a low lightfastness. Copper phthalocyanine dye C.I. DirectBlue 199 is suited for many applications due to its superior lightfastness and thermal stability. To improve its moderate waterfastness on plain paper, novel cyan dyes have been launched based on the differential solubility approach by introducing carboxyl groups into the phthalocyanine moiety [3,12],... 

Positively charging CCAs are organic molecules with a positive charge. Colored positive CCAs tend to be the black Nigrosine dyes, which are mixtures of compounds in which highly arylated phenazines (8) are the major component. Colorless positive CCAs tend to contain a quaternary nitrogen atom cetylpyridi-nium chloride (9), also found in antiseptic mouthwashes, is one of the most widely used [2,3], Triphenylmethane, benzimidazolium and beta di- and tri-car-bonyl compounds are also used [6],... 

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