1,12-Diazadibenzo(a,i)pyrene 16566-64-6 3,14-Diazabenzo(d,l)pyrene Dipyrido(2,3-d,2,3-l)pyrene NAPHTHO(1,8-gh:4,5-g'h')DIQUINOLINE Naphtho(1,8-sh:4,5-s'h')diquinoline