Synthesis and Structures of Oxygen‐Bridged Triphenylamine in Neutral, Radical Cation, and Dication States

Abstract We have designed and synthesized a highly electron‐rich compound, an oxygen‐bridged triphenylamine incorporating methylthio groups. The radical cation and dication salts were successfully obtained by oxidation reactions of this compound as isolable solids. X‐ray crystallographic analyses of these oxidized species revealed planarized triphenylamine π‐electronic structures compared to the neutral species. Bond length variations suggest that resonance structures in the π‐electron system of the oxidized species contribute to their stability. The electronic spectra of the oxidized species exhibited strong near‐infrared absorption bands. Additionally, the spectra remained nearly unchanged under the measurement conditions and in air‐saturated solution, confirming the stability of these species.