The molecule is an aminonaphthalenesulfonic acid that is 3,3'-[[1,1'-biphenyl]-4,4'-diylbis(diazene-2,1-diyl)]di(naphthalene-1-sulfonic acid) in which the two hydrogens at the 4-positions on the naphthalene rings are placed by amino and hydroxy groups. The disodium salt is the histological dye 'Congo corinth'. It has a role as a fluorochrome and a histological dye. It is an aminonaphthalenesulfonic acid, a member of azobenzenes, a bis(azo) compound, a member of naphthols and a ring assembly. It is a conjugate acid of a Congo corinth(2-).
4-amino-3-[[4-[4-[(1-hydroxy-4-sulfonaphthalen-2-yl)diazenyl]phenyl]phenyl]diazenyl]naphthalene-1-sulfonic acid