4 : 4 -Diaminostilbene-2 : 2 -disulphonic acid

Approximately 75% of fluorescent brighteners belong to the stilbene class. These are almost invariably derived from 4,4, diaminostilbene 2,2, disulphonic acid (1.6 X = NH2), often condensed with cyanuric chloride to take advantage of the further contribution of the s-triazine rings to substantivity for cellulose. 

The TLC of optical brighteners or bleaches, derived from 4,4 -diaminostilbene-2,2 -disulphonic acid, has been described by Theidel [86]. He was able to separate the cis and trans isomers on polyamide layers, using methanol-ammonium hydroxide-water (66 + 27 + 7) surprisingly the cis-compound migrated ahead of the trans-. The opposite order was found in TLC experiments of Latestak [50] on silica gel G, using the solvents n-propanol-5% sodium bicarbonate solution (66 + 33), n-butanol-pyridine-water (33 + 33 + 33) and amyl alcohol-p3n idine-25 % ammonium hydroxide (33 + 33 + 33). The substances were detected by observation in UV light. 

CCRIS 4430 Diaminostilbene disulphonate disodium salt 4,4 -Diamino-2.2 -stilbenedisulfonic acid, disodium salt p.p -Diaminostilbene-o,o -disulfonio acid disodium salt Disodium 4,4 -diaminostilbene-2,2 -disulphonate 2,2 -Disulfo4,4 -slilbenediamine disodium salt EINECS 230-847-3 Flavonic acid disodium salt 2,2 -Stilbenedisulfonic acid, 4,4 -diamino-, disodium sail. 

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