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Tuning Optical Properties of Covalent Organic Multicycles via Linkage Variation
Li-Peng Wu1, Tong Yang1, Lin-Zhuo He1
1State Key Laboratory of Natural Product Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu730000, China.
ACS Applied Materials & Interfaces
|August 13, 2026
Summary
Linkage chemistry, specifically vinylene versus imine, significantly tunes the optical and electronic properties of covalent organic multicycles (COMs). Vinylene-linked COMs show enhanced charge separation, transfer, and fluorescence compared to imine-linked counterparts.
Area of Science:
- Organic Chemistry
- Materials Science
- Photophysics
Background:
- Tuning optical properties of cyclic organic architectures typically relies on skeleton design.
- The influence of linkage chemistry on optoelectronic properties is underexplored.
Purpose of the Study:
- To investigate the impact of linkage chemistry (vinylene vs. imine) on the optoelectronic properties of covalent organic multicycles (COMs).
- To demonstrate linkage variation as a strategy for modulating COM properties.
Main Methods:
- Rational design and synthesis of two vinylene-linked and two imine-linked COMs.
- Utilized Knoevenagel and Schiff-base condensation for synthesis.
- Characterization using optical spectroscopy, femtosecond-transient absorption, and photocurrent measurements.
Main Results:
- Vinylene-linked COMs displayed narrower optical bandgaps and lower HOMO levels than imine-linked COMs.
- Higher photoluminescence quantum yields and longer fluorescence lifetimes were observed in vinylene-linked COMs.
- Superior charge separation and transfer efficiency were evident in vinylene-linked COMs.
Conclusions:
- Linkage chemistry is a critical, yet underexplored, factor in tuning COM optoelectronic properties.
- Vinylene linkages offer a promising route to enhance charge transport and fluorescence in COMs.
- This study provides a new strategy for designing advanced organic electronic materials.
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