Synonyms: 1H-Benz[e]indolium,3-butyl-2-[5-(3-butyl- 1,3-dihydro-1,1-dimethyl-2H-benz[e]indol- 2-ylidene)-1,3-pentadienyl]-1,1-dimethyl-,perchlorate;NK 3219;NC 22;3-butyl-2-[(1E,3E)-5-(3-butyl-1,1-dimethyl-1,3-dihydro-2H-benzo[e]indol-2-ylidene)-1,3-pentadienyl]-1,1-dimethyl-1H-benzo[e]indolium perchlorate;