Synthesis, post-functionalization, and photoluminescence of contorted diazaphosphepine-based polycyclic aromatic heterocycles?

Dalton Transactions Pub Date: 2023-06-02 DOI: 10.1039/D3DT00958K

Abstract

Heteroatom-doped organic π-conjugated molecules (OCMs) have become one type of emerging optoelectronic material with intriguing functionalities. Phosphorus (P)-doped OCMs are a special member of heteroatom-doped OCMs where rich P-chemistry is able to fine-tune their optoelectronic properties. Herein, we report a new series of nonplanar diazaphosphepine-based polycyclic aromatic heterocycles (DPP-PAHs). Efficient and mild double P–N cyclization allowed one to readily incorporate two P-centers in DPP-PAHs. With nonplanar diazaphosphepine rings, DPP-PAHs exhibit contorted structures in single crystal structures. The functionalization of double P-centers by H2O2 and S8 gave DPP-PAHs with P[double bond, length as m-dash]O and P[double bond, length as m-dash]S centers, respectively. Compared with the parent small molecule, the DPP-PAHs exhibit high photoluminescence quantum yields. Our experimental and theoretical studies further revealed that both P-environments and conjugated backbones have impacts on the photophysical properties of the DPP-PAHs.

Graphical abstract: Synthesis, post-functionalization, and photoluminescence of contorted diazaphosphepine-based polycyclic aromatic heterocycles
Recommended Literature