Stable Radical Cations of N,N'-Diarylated Dihydrodiazapentacenes.
Gaozhan XieVictor BrosiusJie HanFrank RomingerAndreas DreuwJan FreudenbergUwe H F BunzPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2019)
A series of quinoidal N,N'-diaryldiaza-N,N'-dihydropentacenes (Quino) was prepared in a two-step reaction, starting from quinacridone. Oxidation of Quino furnishes stable radical cations, isoelectronic to the radical anions of the azaacenes, whereas the dicationic species are isoelectronic to neutral azapentacenes. The spectroscopic properties of the diaryldiazapentacenes and their oxidized mono- and dications are equivalent to that of the dianion of tetraazapentacene (TAP), its radical anion and the neutral TAP.