Stilbene Dyes

Abstract

Stilbene dyes of importance are mostly direct yellow dyes for cellulosic fibers, especially paper. There have been several red and blue stilbene‐containing dyes reported but none have been developed to commercial importance. There are brown leather dyes which are stilbene‐based. Most stilbene dyes are derived from 4‐nitrotoluene‐2‐sulfonic acid which is oxidized under alkaline conditions to 4,4′‐dinitro‐2,2′‐stilbenedisulfonic acid, which can be further condensed to yellow dyes or reduced to 4,4′‐diamino‐2,2′‐stilbenedisulfonic acid. The latter can be tetrazotized and coupled to yield dyes of reasonably definitive structure. 4,4′‐Diamino‐2,2′‐stilbenedisulfonic acid is more important as an intermediate for fluorescent brighteners than for dyes. Dyes produced by alkaline condensation of 4‐nitrotoluene‐2‐sulfonic acid or 4,4′‐dinitro‐2,2′‐stilbenedisulfonic acid are listed as a subclass of azo dyes. Those dyes derived from coupling the tetrazo of 4,4′‐diamino‐2,2′‐stilbenedisulfonic acid are listed as regular azo dyes. Since 1980 activity has been reported in all known areas of stilbene dye chemistry, but it is minuscule compared to other dye chemistries. There were reports of using 4,4′‐diaminostilbene‐2,2′‐disulfonic acid as a bridging group in reactive dyes and one report of stilbene participating in the chromophore. Basic dyes reported were made by coupling the tetrazo of 4,4′‐diaminostilbene and quaternizing. The most important stilbene dyes are those known for more than fifty years. The commercial importance of Direct Yellow 11 (1883), Direct Orange 15 (1888), Direct Yellow 4 (1886), and Direct Yellow 106 (1936) attests to the value, properties, and durability of stilbene yellow dyes.

A review of semi-rigid, stilbene-containing alternating copolymers

“…optical brighteners, dyes, etc. [1,40]. Many applications of stilbene derivatives have resulted in a large library of substituted stilbene small molecules and facile synthetic techniques to enable synthesis of a variety of derivatives many of which can serve as copolymerizable monomers.…”