9-methoxy-2-(2-{1'-[2-(10-methoxy-7-methyl-7H-pyrido[4,3-c]carbazol-2-ium-2-yl)ethyl]-4,4'-bipiperidin-1-yl}ethyl)-7-methyl-7H-pyrido[4,3-c]carbazol-2-ium dichloride