Electronic structures of two-dimensional π-conjugated boroxine covalent organic frameworks

Boroxine covalent organic frameworks (boroxine COFs) can be referred to as two-dimension (2D) polymer networks with cores of boroxine connected with rigid linker and extended in x or y dimensions, which might be good candidates for organic electronic and luminescence material. However, the engineering COFs with improved charge transfer and conduction properties based on pore size and linker structure still confront various challenges. Here, we investigate the geometrical structure and electronic properties with linkers from phenyl to biphenyl and the replacement of H with F atom in 2D scale with the CRYTSTAL17 software at the density functional theory (DFT) level with the global-hybrid PBE0 functional and POB-TZVP basis set, using a 5 × 5 k-point mesh. The increased pore diameter reduced their energy gap. Replacing the F atom with the H atom lowered their VBMs and conduction band minimums (CBMs). Computation results can assist the experimental scientist in producing highly conductive 2D boroxine COFs.