Dyes synthetic Rhodamine

Nguyen, T. and Francis, M. B. (2003). Practical synthetic route to functionalized rhodamine dyes. Org. Lett. J, 3245-3248. 

TLC coupled with mass spectrometry employing desorption electrospray ionization has been used for the separation of synthetic dyes. The chemical structures of dyes included in the investigation are shown in Fig. 3.7. ODS HPTLC plates (10 X 10 cm) were used as the stationary phase the mobile phase consisted of methanol-tetrahydrofuran (60 40, v/v) containing 50-100 mM ammonium acetate for the positive-ion test and of methanol-water (70 30, v/v) for the negative-ion test. Test mixtures for negative- and positive-ion mode detection consisted of methyleneblue, crystal violet, rhodamine 6G... 

Mauveine, the original synthetic dye, was of the azine type, its principal component being compound 6.24. This particular group of dyes is now essentially only of historic interest. Xanthene dyes, such as Rhodamine B, Cl Basic Violet 10, 6.25, Rhodamine 6G, Cl... 

The research tasks of the central laboratory at BASF between 1890 and 1914 were related mainly to the well established requirements of the dye-using industries. Direct azo dyes and the rhodamines were major research fields. In 1897 these were supplemented by the sulphur dyes, at that time also a main research area. In 1899, azo lake dyes were a new and very successful form of application. The twentieth century started with novel research into the anthraquinones, until then completely dominated by the alizarin laboratory. This widened the research potential for research into the important indanthrene-type vat dyes. Just before World War I the main laboratory participated in diversification with catalytic hydrogenation and the invention of synthetic tanning agents. In this period, the central laboratory controlled the core technology, and the most important market of BASF, namely the dyestuff business. The research laboratories of the aniline and the alizarin departments continued with the same tasks in their respective fields. 

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