An extremely redox-active air-stable neutral π radical: dicyanomethylene-substituted triangulene with a threefold symmetry

Radically active: A redox-active air-stable neutral π radical (1(·)) with three dicyanomethylene groups introduced with threefold symmetry into a triangulene π skeleton instead of the oxygen atoms of TOT(·) was designed, synthesized, and characterized (see figure). The enhanced electron-accepting ability and extended π-electronic system of this chemical modification gave an extremely small SOMO-LUMO gap and significantly lowered the frontier orbital energies, leading to the remarkable increase in the redox stages.