Fluoranthene and benzo [k] fluoranthene (3) are nonalternant polyaromatic hydrocarbons. Their derivatives, 3-acetyl, 8-acetyl, 3-nitro, and 3-aminofluoranthenes (4, 5, 7, and 8) were reacted in FSO 3 H/SO 2 ClF and the solutions were observed by NMR measurements at low temperatures, which showed the formation of PAH-substituted onium ions. The most deshielded 13 C peaks in fluoranthene frames were observed at 155.7 and 148.7 ppm for ...