Synonyms: 3H-Indolium,2-[2-[2-chloro-3-[(1,3- dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)- ethylidene]-1-cyclohexen-1-yl]ethenyl]-1,3,3- trimethyl-,perchlorate;CY 2;2-(2-{2-Chloro-3-[2-(1,3,3-trimethyl-1,3-dihydro-2H-indol-2-ylidene)ethylidene]-1-cyclohexen-1-yl}ethenyl)-1,3,3-trimethyl-3H-indolium perchlorate;