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Published on: December 27, 2018
Engineering Cofacial Trizinc(II)porphyrin Trimers: Linking Molecular Architecture with Excited-State Dynamics
Chandrani Pal1, Dolly Chandel1, Jiyeon Lee2
1Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Inorganic Chemistry
|June 29, 2026
Summary
We designed donor-acceptor-donor Zn(II)porphyrin trimers with distinct conformations. The "closed" ABA form shows enhanced charge transfer and superior photocatalysis, while the "open" ACA form exhibits weaker coupling and monomer-like fluorescence.
Area of Science:
- Supramolecular Chemistry
- Photochemistry
- Materials Science
Background:
- Donor-acceptor-donor (D-A-D) Zn(II)porphyrin trimers are investigated for their electronic and photophysical properties.
- Conformational flexibility in molecular systems can significantly influence their excited-state behavior and reactivity.
Purpose of the Study:
- To rationally design D-A-D Zn(II)porphyrin trimers with distinct conformational architectures (ABA and ACA).
- To investigate the impact of conformational changes on electronic coupling, excited-state dynamics, and photocatalytic activity.
Main Methods:
- Synthesis and characterization of D-A-D Zn(II)porphyrin trimers with ABA ('closed') and ACA ('open') conformations.
- Spectroscopic analysis (UV-Vis absorption, fluorescence) to probe electronic coupling and excited-state behavior.
- Photocatalytic experiments to assess oxidation efficiency.
Main Results:
- The 'closed' ABA conformer exhibits strong excitonic coupling and enhanced intramolecular charge-transfer (ICT) interactions.
- The 'open' ACA conformer shows weaker coupling, minimal spectral distortion, and monomer-like fluorescence with a longer excited-state lifetime.
- ABA demonstrates a higher singlet oxygen quantum yield and superior photocatalytic activity compared to ACA.
Conclusions:
- Conformational modulation of D-A-D Zn(II)porphyrin trimers significantly impacts their electronic coupling and excited-state properties.
- The 'closed' ABA architecture facilitates efficient ICT, leading to enhanced photooxidation capabilities.
- This study highlights conformational control as a viable strategy for designing efficient photocatalysts for selective photooxidation.
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