Mixed‐Valence BN‐Doped Corannulene Trimer Radical Cations

Abstract

AbstractMixed‐valence (MV) dimers have been extensively investigated, however, the structure and properties of purely organic MV trimers based on open‐shell polycyclic aromatic hydrocarbons remain elusive. Herein, unprecedented MV BN‐doped corannulene radical cations [BN‐Cor1]3⋅⋅2+ ⋅ 2[BArylF4]− and [BN‐Cor2]3⋅⋅2+ ⋅ 2[BArylF4]− were synthesized via chemical oxidation, and their structures were unambiguously confirmed by single‐crystal X‐ray diffraction. These uncommon radical cations consist of three corannulene cores and two [BArylF4]− anions, and three corannulene motifs [BN‐Cor1]3⋅⋅2+ and [BN‐Cor2]3⋅⋅2+ in the unit cell exhibit a trimer structure with a slipped π‐stacking configuration. Detailed structural analyses further revealed that the corannulene cores exhibit an infinite layered self‐assembly configuration, allowing their potential applications as building blocks for molecular conductors. The detection of a forbidden transition (Δms=±2) by electron paramagnetic resonance (EPR) spectroscopy further confirmed the existence of two unpaired electrons in the π‐trimers and the MV characteristic of these two species. Variable‐temperature EPR and conductivity measurements suggested that the BN‐doped π‐trimers exhibited antiferromagnetic coupling and conductivity properties.