Electron-Deficient Polycyclic π-System Fused with Multiple B←N Coordinate Bonds

An extensive polycyclic pi-system with 23 fused rings is synthesized via a highly efficient borylation reaction, in which four B-N covalent bonds and four B <- N coordinate bonds are formed in one pot. B <- N coordinate bonds not only lock the backbone into a near-coplanar conformation but also decrease the LUMO energy level to around -3.82 eV, demonstrating the dual utility of this strategy for the synthesis of extensive rigid polycyclic molecules and the development of n-type conjugated materials for organic electronics and organic photovoltaics.

Automated summary

An extensive polycyclic pi-system with 23 fused rings was synthesized via a highly efficient borylation reaction, forming four B-N covalent bonds and four B <- N coordinate bonds. The B <- N coordinate bonds not only lock the backbone into a near-coplanar conformation but also decrease the LUMO energy level, demonstrating the dual utility of this strategy for the synthesis of rigid polycyclic molecules and the development of n-type conjugated materials for organic electronics and photovoltaics.