1-butyl-2-((E)-2-((E)-3-((Z)-2-(1-butylbenzo[cd]indol-2(1H)-ylidene)ethylidene)-2-chlorocyclopent-1-en-1-yl)vinyl)benzo[cd]indol-1-ium iodide, Benz[cd]indolium, 1-butyl-2-[2-[3-[2-(1-butylbenz[cd]indol-2(1H)-ylidene)ethylidene]-2-chloro-1-cyclopenten-1-yl]ethenyl]-, iodide (1:1)