The molecule is an organosulfonate oxoanion which is the trianion obtained by the deprotonation of the sulfo groups of tetrasulfocyanine acid. It is a conjugate base of a tetrasulfocyanine acid.
(2E)-2-[(2E,4E,6E)-7-[3,3-dimethyl-5-sulfonato-1-(2-sulfonatoethyl)indol-1-ium-2-yl]-4-methylhepta-2,4,6-trienylidene]-3,3-dimethyl-1-(2-sulfonatoethyl)indole-5-sulfonate