Applications thiazine dyes

Oxazine, azine and thiazine dyes are named for the characteristic heterocyclic ring systems 1,4-oxazine, 1,4-diazine, and 1,4-thiazine. The dyes are generally cationic (basic) or acid dyes. They also can be reduced to colorless forms, then oxidized back to the dye, as in vat dyeing. The dyes also have been used to a limited extent in disperse and fiber reactive applications. They are used as titration indicators and may be applied to acrylic fibers and leather. 

Azine, oxazine, and thiazine dyes were historically more important than they are at present. However, at least one example of each, introduced more than 100 years ago, is still offered commercially today (1,2). Azo and anthraquinone dyes have largely displaced them in commercial application. Azo dyes (qv) offer better fastness and broader shade ranges at more economical prices. 

Luo, H. Q. Liu, S. R Liu, Z. F. Liu, Q. Li, N. B. Resonance Rayleigh scattering spectra for studying the interaction of heparin with some basic pheno-thiazine dyes and their analytical applications. Anal Chim. Acta 2001, 449, 261-270. 

Phenazine leuco dyes, like their thiazine and oxazine analogues, have also found application in electrolytic recording, overhead transparencies, and Color Dry Silver. The phenazine leuco 48 is employed in electrolytic recording,17 whereas compounds 49, 50 are described as useful in thermographic and photothermographic systems.18... 

The third chapter deals with leuco derivatives of the oxazine, thiazine, and phenazine dyes, and is written by Tran Van Thien, who has had many years experience in photoimaging at the 3M Research Center, Harlow. His industrial experience in leuco dyes has enabled him to produce a collation of material impossible to find elsewhere in a single review, and again recipes for the synthesis of representative examples abound. Consideration is also given to the numerous applications of these molecules in thermal and photo-imaging systems. 

The book is divided into seven chapters. Chapter 1 describes photo-chromic materials which have critical applications in memory technology. These compounds generally are activated by light. Chapter 2 covers leuco quinones which, in many cases, when oxidized, have their absorption maxima in the near-infrared region. Chapter 3 describes leuco dyes of a common group of compounds—oxazine, thiazine, and phenazines—that have found applications in color photography. Chapters 4-6 describe arylmethine-type compounds that can be triggered to dyes by common chemistry. Chapter 7 describes a special class of leuco dyes, namely, tetra-... 

Dye Classification Based on chemical structure or chromophore, 20-30 different groups of dyes can be discerned. Azo (monoazo, disazo, triazo, polyazo), anthraquinone, phtha-locyanine and triarylmethane dyes are quantitatively the most important groups. Other groups are diarylmethane, indigoid, azine, oxazine, thiazine, xanthene, nitro, nitroso, methine, thiazole, indamine, indophenol, lactone, aminoketone and hydroxyketone dyes and dyes of undetermined structure (stilbene and sulphur dyes). The vast array of commercial colourants is classified in terms of colour, structure and application method in the Colour Index (C.I.), which has been edited since 1924 (and revised every three months) by the Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists. Each dye is given a C.I. generic name determined by... 

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