Facile Route to Novel Diazaphosphinine‐Based Polycyclic Aromatic Hydrocarbons.

Doping main‐group elements has become a unique strategy to fine‐tune optoelectronic properties of organic π‐conjugated molecules. Herein, we report the first example of diazaphosphinine based polycyclic hydrocarbons (DP‐PAHs) via facile synthetic protocols. Synthesis of diazaphosphinine heterocycles harnesses mild and efficient P−N chemistry. The heterocycles readily undergo photocyclizations by using only oxidants. The photocyclization protocol is applicable to the heterocycles with various P‐centers. We successfully extended the protocols in extended DP‐PAHs with 13‐fused aromatic rings. Further adjusting P‐chemistry allows to efficiently fine‐tune the singlet and triplet emission characteristics. More importantly, single‐molecule white‐light‐emitting character was achieved via the balanced singlet and triplet emission of DP‐PAH. Therefore, this work opens up new horizons in the area of organic π‐conjugated materials. [ABSTRACT FROM AUTHOR]