carbopolycyclic compound 6-Nitrochrysene C18H11NO2 273.07898 CAS:7496-02-8 chebi_ontology 273.28540 CHEBI:82351 [O-][N+](=O)c1cc2c3ccccc3ccc2c2ccccc12 UAWLTQJFZUYROA-UHFFFAOYSA-N 0 InChI=1S/C18H11NO2/c20-19(21)18-11-17-13-6-2-1-5-12(13)9-10-15(17)14-7-3-4-8-16(14)18/h1-11H KEGG:C19271