Indigoid dyes

Indigoid Dyes. Like the anthraquinone, ben2odifuranone, and polycycHc aromatic carbonyl dyes, the indigoid dyes also contain carbonyl groups. They are also vat dyes. 

Indigoid dyes represent one of the oldest known classes of dyes. For example, 6,6 -dibromoindigo [19201 -53-7] (44) is Tyrian Purple, the dye made famous by the Romans. Tyrian Purple was so expensive that only the very wealthy were able to afford garments dyed with it. Indeed, the phrase "bom to the purple" is still used today to denote wealth. 

Hsynthesis from, 3, 767 Indenobenzazepines pharmacological properties, 7, 546 Indenone oxide, 2,3-diphenyl-photochromic compound, 1, 385 In deno[ 1,2-c][ 1,2,4]triazines synthesis, 3, 434 Indicated hydrogen nomenclature, 1, 33 Indigo, I, 317, 318-319, 4, 370 Baeyer synthesis, 1, 319 colour and constitution, 1, 344-345 molecular structure, 4, 162 photochromic compound, 1, 386 synthesis, 4, 247 Indigoid dyes... 

Selenobiotin synthesis, 4, 968 Seleno indigo synthesis, 4, 959 Seleno indigoid dyes applications, 4, 971 Selenolane, octafiuoro-synthesis, 4, 967 Selenolane, tetrafiuoromethyl-synthesis, 4, 967 Selenolo[3,4-b]benzofuran, aryl-synthesis, 4, 1076... 

In context with the formation of peraminosubstituted 1,4,5,8-tetraazaful-valenes of type 85 it must be mentioned that the bis-vinylogous compounds 94 can be easily prepared by reaction of acetamidine with bisimidoylchlo-rides derived from oxalic acid (96S1302). In the course of a complex reaction a cyclic ketene aminal was produced it immediately underwent an oxidative dimerization to yield deeply colored TAFs. Tlieir high chemical stability can be compared with that of indigoid dyes and manifests itself, for example, by the fact that they are soluble in hot concentrated sulfuric acid without decomposition. Tire same type of fulvalene is also available by cy-... 

HPLC-UV-Vis-ESI MS was used to identify indigoid dyes in blue fibre extracts taken from a Japanese tapestry (nineteenth century). Two main colourants were recognized as indigotin and Methylene Blue, [44] a thiazine cationic dye first synthesized at the end of the nineteenth century, commonly used for silk and cotton dying (Figure 13.9). 

M. Puchalska, K. Polec Pawlak, I. Zadrozna, H. Hryszko and M. Jarosz, Identification of indigoid dyes in natural organic pigments used in historical art objects by high performance liquid chromatography coupled to electrospray ionization mass spectrometry, J. Mass Spectrom., 39, 1441 1449 (2004). 

Indigenous biocontrol species, 13 347 Indigo, color, 7 332 Indigoid dyes, 9 256... 

C. Galindo, P. Jacques and A. Kalt, Photochemical and photocatalytical degradation of an indigoid dye a case study of acid blue 74 (AB74). J. Photochem. PhotobioLA Chem., 141 (2001) 47-56. 

---