Syntheses and Physical Properties of Cationic BN‐Embedded Polycyclic Aromatic Hydrocarbons

Cationic BN‐embedded polycyclic aromatic hydrocarbons (BN‐PAH + s) were synthesized from a nitrogen‐containing macrocycle via pyridine‐directed tandem C−H borylation. Incorporating BN into PAH + resulted in a remarkable hypsochromic shift due to an increase in the LUMO energy and the symmetry changes of the HOMO and LUMO. Electrophilic substitution or anion exchange of BN‐PAH + possessing tetrabromoborate as a counter anion ( BN + [BBr 4 − ] ) afforded air‐stable BN‐PAH/PAH + s. Of these, BN + [TfO − ] allowed reversible two‐electron reduction and the formation of two‐dimensional brickwork‐type π‐electronic ion pair with 1,2,3,4,5‐pentacyanocyclopentadienyl anion, demonstrating the potential application of BN‐PAH + as electronic materials.