122 / 2023-10-10 23:34:29

Exploring P-N Chemistry in Six-Membered Phosphinines: Synthesis and Photophysical Properties

Diazaphosphinine; Phosphorus Heterocycles; Photophysical Properties; Polycyclic Hydrocarbons

Phosphorus Material Chemistry and Applied Science > 2) Phosphorus chemistry in agriculture and food science

Organic π-conjugated molecules (OCMs) have attracted significant attention in the areas of organic catalysts, bio-imaging/sensing, and organic optoelectronics.^1-3 Rich chemical diversity of OCMs maintains their unique positions in the applications mentioned above. Recently, introducing main-group elements (such as B, N, S, Si, P, etc.) into OCM has become a powerful strategy for fine-tuning photophysics, redox characteristics, molecular organizations, and optoelectronic functionalities of the OCMs. 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.