Three-Supercenter\nTwo-Electron Bonds in C<sub>16</sub>H<sub>10</sub>: Two-Dimensional\nAnalogue of Halogen-Bridge Bonding

Three-center two-electron bridging bonding plays a vital\nrole in\nrationalizing structures and stabilities of certain molecules. Herein,\nthe π electron rule of pyrene (C<sub>16</sub>H<sub>10</sub>)\nwas unraveled based on a newly proposed two-dimensional (2D) superatomic-molecule\ntheory, where the superatomic sextet rule was regarded as a π\nelectron counting target. C<sub>16</sub>H<sub>10</sub> can be taken\nas a <sup>◊</sup>N<sub>2</sub><sup>◊</sup>F<sub>2</sub> superatomic molecule, where <sup>◊</sup>N and <sup>◊</sup>F denote 2D superatoms bearing 3π and 5π electrons, respectively.\nInterestingly, it represents the first 2D superatomic halogen-bridge\nmolecule, which realizes π electronic shell-closure via two\nthree-supercenter two-electron bridging bonds. Additionally, a N-doped\nnanoporous graphene with a wide band gap (1.22 eV) was designed based\non C<sub>16</sub>H<sub>10</sub>, which can be considered as a periodic\naggregate of 2D superatomic wires composed of 2π-<sup>◊</sup>C and bridging <sup>◊</sup>F superatoms. This work enriches\nthe 2D superatomic-molecule chemistry and provides a practicable bottom-up\nassemble approach to obtain 2D functional materials with tunable band\ngaps.