disodium hydrogen bis[4-[[2,6-dihydroxy-3-[(2-hydroxy-3,5-dinitrophenyl)azo]phenyl]azo]-3- methylbenzenesulphonato(3-)]chromate(3-)

2-Amino-4,6-dinitrophenol diazo, acetic acid with Resorcinol coupling, 4-Amino-3-methylbenzenesulfonic acid?diazo, and the generation of single accidentally coupled nitrogen compounds, then with aqueous acid chromium heating, in 100 ~ 102 ℃ to keep four hours, create chromium complex.

dark red light brown.