The Radical Anion and Dianion of Tetraazapentacene

The mono‐ and bis‐reduction of 6,13‐bis((triisopropylsilyl)ethynyl)quinoxalino[2,3‐b]phenazine (1) with potassium anthracenide in THF is reported. Both the radical anion 1.− and the dianion 12− were isolated and characterized by optical and structural (single‐crystal X‐ray diffraction) methods. Solutions of the radical anion 1.− were stable in air for several hours and characterized by EPR spectroscopy. Dianion 12− is highly fluorescent and photostable. Charged but not pinned down! The reduction of the symmetrical tetraazapentacene with potassium metal in THF gives the radical anion, a species critical in charge transport in field effect transistors. The negative charge is shown to be equally distributed over the whole molecule and not localized or pinned on the electronegative nitrogen atoms.