Benzenamine,4,4',4'',4''',4'''',4'''''-[(9,9-diethyl-9H-fluorene-2,4,7-triyl)tris[2,1-ethenediyl(9,9-diethyl-9H-fluorene-4,2,7-triyl)di-2,1-ethenediyl]]hexakis[N,N-diphenyl-