Electronic manipulation of boron centers in polycyclic aromatic hydrocarbon (PAHs) frameworks often leads to unique redox and photophysical properties. Herein, we report the first isolation and redox investigation of carbene-stabilized 6,12-diboraanthanthrenes 3/4 with electron-rich boron centers. Combining experimental and theoretical studies confirms that 3/4 exhibits a closed-shell singlet ground state and strong global aromaticity. Oxidation of 3/4 with TEMPO led to the oxidized product 5. Furthermore, the reversible one or two-electron oxidation process for 3/4 has been confirmed by cyclic voltammetry. Sequential oxidation of 3/4 with AgSbF6 results in the isolable radical monocations 6/7, and dications 8/9. The radical character of 6/7 is confirmed by multi-line EPR spectra, with the hyperfine coupling splitting mainly attributed to the two boron nuclei. As rare diboron-doped dicationic PAHs, 8/9 display bright yellowish fluorescence. Reduction of 3/4 with 2 equivalents of KC8 leads to the formation of the dianionic species 10/11, where the carbene ligands are initially reduced and subsequently reconstructed, confirming the electron-rich nature of boron centers.
