New Sulfur Dyes (Hyaman Colors)

Natural Dyes, Our Global Heritage of Colors

Sulfur Dyes and Their Application

Part 1 of this chapter covers the chemical development of sulfur dyes and the general principles of their application to cotton. Sulfur dye reduction and oxidation are compared with those of vat dyes. The effect of different chemicals on each part of the dyeing process is discussed with respect. to their cost, benefits and environmental impact.

Synthesis of new asymmetric xanthene dyes via catalyst-free S(N)Ar with sulfur nucleophiles.

Addition of a single functional handle to the tricyclic moiety of fluorescein results in asymmetric xanthene dyes. Our synthesis of a new class of asymmetric xanthenes proceeds via an unusual SNAr with sulfur nucleophiles on electron rich aromatic xanthenes scaffolds in the absence of a metal catalyst. The resulting 3'-thioethers exhibit high photostability and are conveniently converted into r...

New energy transfer dyes for DNA sequencing.

We have synthesized a set of four energy transfer dyes and demonstrated their use in automated DNA sequencing. The donor dyes are the 5- or 6-carboxy isomers of 4'-aminomethylfluorescein and the acceptor dyes are a novel set of four 4,7-dichloro-substituted rhodamine dyes which have narrower emission spectra than the standard, unsubstituted rhodamines. A rigid amino acid linker, 4-aminomethylbe...

New squaraine dyes for photodynamic therapy

Photodynamic therapy (PDT) [1]consists in the activation of molecular oxygen under irradiation by light in the presence of photodrugs (photosensitizers, PS) that have been previously selectively accumulated in the target tissues. In comparison with conventional treatment methods, PDT is considered to be a clinical treatment with high safety, few side effects, reliable repeatability, and relativ...