The molecule is an organosulfonate oxoanion resulting from the removal of a proton from both of the sulfo groups of 4,5-dihydroxy-3-(phenyldiazenyl)naphthalene-2,7-disulfonic acid. It is a conjugate base of a 4,5-dihydroxy-3-(phenyldiazenyl)naphthalene-2,7-disulfonic acid.
4,5-dihydroxy-3-phenyldiazenylnaphthalene-2,7-disulfonate