Sodium 4-((4-((2-phenyl-1H-indol-3-yl)azo)phenyl)azo)benzenesulphonate, Sodium 4-[[4-[(2-phenyl-1H-indol-3-yl)azo]phenyl]azo]benzenesulphonate, Benzenesulfonic acid, 4-(2-(4-(2-(2-phenyl-1H-indol-3-yl)diazenyl)phenyl)diazenyl)-, sodium salt, Benzenesulfonic acid, 4-[2-[4-[2-(2-phenyl-1H-indol-3-yl)diazenyl]phenyl]diazenyl]-, sodium salt