N,N'-Bis(4-methoxy-2-methylphenyl)-N,N'-diphenylbenzidine;N,N'-Bis(4-methoxy-2-methylphenyl)-N,N'-diphenylbenzidine (purified by sublimation);N,N'-Bis(4-methoxy-2-methylphenyl)-N,N'-diphenylbenzidine;N,N'-Bis(4-methoxy-2-methylphenyl)-N,N'-diphenylbenzidine (purified by sublimation)