4-amino-5-hydroxy-3-[(4-nitrophenyl)diazenyl]-6-[(4-sulfonatophenyl)diazenyl]naphthalene-2,7-disulfonate
4-amino-5-hydroxy-3-[(4-nitrophenyl)diazenyl]-6-[(4-sulfonatophenyl)diazenyl]naphthalene-2,7-disulfonate
An organosulfonate oxoanion obtained by deprotonation of the sulfonic acid groups of naphthalene blue black CS (acid form).