fig7

Figure 7. DFT calculations (A) HOMO and LUMO orbitals and energy levels of the TANB-Py-COF fragment; (B) ESP map with dipole moment of the TANB-Py-COF fragment; (C) Electron-hole distribution of the TANB-Py-COF fragment. DFT: Density functional theory; HOMO: highest occupied molecular orbital; LUMO: lowest unoccupied molecular orbital; ESP: electrostatic potential; COF: covalent organic framework.