A Trithia‐Bridged <i>N</i>‐Heterotriangulene: The Hitherto Missing Electron Donor

Abstract The very first representative of trithia‐bridged N ‐heterotriangulene, a triphenylamine with sulfur atoms bridging the ortho ‐positions, was synthesized by a sequence of regioselective sulfenylation with phthalimidesulfenyl chloride followed by Lewis acid‐catalyzed electrophilic cyclization. X‐ray crystallography revealed a saddle‐shaped geometry of the polycyclic scaffold. UV/Vis absorption spectroscopy and cyclic voltammetry were used to characterize the optoelectronic properties. The title compound is a particularly strong electron donor forming a perfectly stable radical cation, which was analyzed by electron paramagnetic resonance spectroscopy and X‐ray crystallography. The electron donor properties were further highlighted by the formation of crystalline donor‐acceptor complexes with strong cyano‐based acceptors.