Electron Density-Dependent Mallory Photocyclization Constructs Rigid Saddle-Shaped Polycyclic Aromatic Hydrocarbons
Beibei Xiao1, Hongbo Li2, Mengjie An1
1Key Laboratory of Cluster Science, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Ministry of Education of China, Beijing, 102488, P. R. China.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|August 28, 2025
Summary
Researchers synthesized three novel saddle-shaped polycyclic aromatic hydrocarbons (PAHs) using Mallory photocyclization. The study details their synthesis, kinetics, and unique photophysical properties, offering a design strategy for luminescent materials.
Area of Science:
- Organic Chemistry
- Materials Science
Background:
- Polycyclic Aromatic Hydrocarbons (PAHs) are crucial in organic electronics.
- Developing nonplanar PAHs with tailored photophysical properties remains a challenge.
Purpose of the Study:
- To synthesize novel saddle-shaped PAHs via Mallory photocyclization.
- To investigate the structure-property relationships governing their luminescence.
Main Methods:
- Mallory photocyclization of bisfluorenylidene-dihydroacene precursors.
- Kinetic studies, UV-Vis absorption, fluorescence spectroscopy, electrochemistry, and low-temperature phosphorescence.
- Structural characterization of synthesized PAHs.
Main Results:
- High yields (77-88%) achieved for three PAHs: bFT-C, bFP-C, and bFP2-C.
- Fastest reaction kinetics observed for anthracene-containing bFP2 due to high electron density.
- Strong solution fluorescence (PLQY: 45-48%) with aggregation-caused quenching (ACQ) in solids.
- Deep-red phosphorescence observed with long lifetimes (72.6–270.0 ms).
Conclusions:
- Precursor architecture significantly influences reaction kinetics and photophysical behavior.
- Demonstrated a design strategy for nonplanar PAHs with tunable luminescence.
- Synthesized PAHs exhibit potential for applications in organic electronics and optoelectronics.
Keywords:
Mallory photocyclizationaggregation‐caused quenchingaromaticitybisfluorenylidene‐dihydroacenessaddle‐shaped PAHsMore Related Videos
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