Soluble indigo blue

At ordinary temperatures, pure ozone is a pale blue gas (d — 2.1415 g/L at 0°C and 101.3 kPa (1 aim)) that can be condensed to an indigo blue liquid, which freezes to a deep blue-violet solid. The solubility of gaseous ozone at atmospheric pressure and 0°C is 1.1 g/I, H20. Gaseous ozone can be adsorbed by porous solid substrates such as silica gel and is often used in this form in organic synthesis. 

Synonyms 2-(l,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene)-2,3-dihydro-3-oxo-lH-indole-5-sulfonic acid disodium salt disodium 5,5 -indigotin disulfonate E132 FD C blue 2 indigotine sodium indigotin disulfonate soluble indigo blue. 

The free acid is obtained by saponification of the ether with an alkali. It forms a crystalline precipitate, sparingly soluble in water. It splits up into indoxyl and carbonic acid on heating. Oxidising agents convert it to indigo blue, W hile on heating with concentrated sulphuric acid indigo sulphonic acid is formed. 

On heating indigo blue with acetic anhydride, sodium acetate, and zinc powder, a diacetylindigo white is obtained. On oxidation with nitrous acid in presence of acetic acid, diacetylindigo blue is formed. This compound forms small glittering red crystals, soluble in benzene with a beautiful red colour. Its constitution is expressed by the formula ... 

The compound 5) was converted into its sodium salt with the appropriate quantity of sodium hydroxide and this proved to be stable, soluble in water, substantive to cellulose, and capable of being oxidized, on the fibre, to Indigotin (Indigo Blue). The anthraquinone dyes react similarly, an example being solubilized Indanthrone, (36). 

Isatiu——obtained by oxidation of indigo-blue, forms shining, transparent, red-brow n prisms. Ik is odorless, sparingly soluble in water, readil soluble in alcohol. 

Indigo-blue powder soluble in methanol, ethanol, acetone and pyriding, giving a deep, inky blue color insoluble in water, benzene and ether. The solution is oxidized almost instantly in air, becoming lighter in color. The dry product reacts spontaneously with atmospheric O3 with considerable evolution of heat and loss of the 2,2 -dipyridyl. 

Indigo carmine (El 32) Indigotine Indigoid Blue Soluble Solid and oral dosage forms... 

Indigo blue org chem C16H10O2N2 A component of the dye indigo, crystallizing as dark-blue rhomboids that break down at 30°C, that are soluble in hot aniline and hot chloroform, and that are also made synthetically used as a reagent and a dye. Also known as Indigo. in-da-go blu ... 

Indigo carmine org chem Ci6H8N2Na208S2 A dark blue powder with coppery luster used as a dye in testing kidney function and as a reagent in detecting chlorate and nitrate. Also known as soluble indigo blue. in-da-go kar-man ... 

Di-Na salt [860-22-0]. Indigo carmine. Soluble indigo blue. C.I. Acid blue 74. C.I. Food blue I. Amacid brilliant blue. Carmine blue. Indigotine. C.I. Pigment blue 63. C.I. 

There are three color additives of the indigoid type, including D C Blue No. 6 (35) (an insoluble pigment), FD C Blue No. 2 (2) (the water-soluble disodium sulfonate derivative of indigo), and D C Red No. 30 (23) (an insoluble thioindigoid). AH are related to indigo [482-89-3] which has stmcture (35) (Fig. 3). 

Vat Dyes. Vat dyes are insoluble in water. Indigo, for example, an ancient blue dye, is probably the best-known example of an ancient vat dye others include woad and Tyrian purple. Since the process of dyeing requires that the dye be in solution, dyeing with a vat dye (or vat dyeing, as the process is known) is possible only after the vat dye has been made soluble by a relatively long and somewhat complicated chemical procedure. The terms vat dye and vat dyeing are probably derived from the large tanks or "vats", in which the process was carried out in ancient times. 

Chloro-triaquo-diammino-cobaltic Sulphate, [Co(NH3)2(H30)3 Ci]S04.H.,0, is obtained by decomposing an aqueous solution of acid dichloro-diaquo-diammino-cobaltic sulphate, [Co(b IIg)2(H20)2Cl2]S04H, with a small quantity of sulphuric acid and evaporating the solution in vacuo. It separates in indigo-coloured crystals and is soluble in water, giving a blue solution. 

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