Benz[cd]indolium,1-ethyl-2-[2-[3-[(1-ethyl- 6-methoxybenz[cd]indol-2(1H)-ylidene)ethylidene]- 2-phenyl-1-cyclopenten-1-yl]ethenyl]- 6-methoxy-,salt with 4-methylbenzenesulfonic acid (1:1)