(benzyl)[4-[[4-[(benzyl)ethylammonio]phenyl](2,4-disulphonatophenyl)methylene]cyclohexa-2,5-dien-1-ylidene](ethyl)ammonium

N-[4-[(2-Sulfonato-4-sulfophenyl)[4-[ethyl(phenylmethyl)amino]phenyl]methylene]-2,5-cyclohexadien-1-ylidene]-N-ethylbenzenemethanaminium