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Updated: Oct 18, 2025
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Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
Published on: August 7, 2018
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Exciton Coupling in Redox-Active Salen based Self-Assembled Metallacycles
Khrystyna Herasymchuk1, Magali Allain2, Gregory A MacNeil1
1Department of Chemistry, Simon Fraser University, Burnaby, V5A 1S6, Canada.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|October 1, 2021
Summary
Researchers created novel supramolecular structures using nickel and ruthenium complexes. These self-assembled metallacycles, including rectangles and catenanes, showed tunable formation and unique electronic properties upon oxidation.
Area of Science:
- Supramolecular Chemistry
- Coordination Chemistry
- Materials Science
Background:
- Nickel salen complexes are redox-active building blocks.
- Homobimetallic ruthenium complexes offer versatile bridging ligands.
- Coordination-driven self-assembly enables the construction of complex architectures.
Purpose of the Study:
- To incorporate redox-active nickel salen complexes into supramolecular assemblies.
- To investigate self-assembly with ruthenium complexes using different bridging ligands.
- To characterize the electronic structure and stability of the resulting oxidized metallacycles.
Main Methods:
- Coordination-driven self-assembly
- Electrochemical experiments (cyclic voltammetry)
- UV-Vis-Near-Infrared (NIR) absorption spectroscopy
- Electron Paramagnetic Resonance (EPR) spectroscopy
- Density Functional Theory (DFT) calculations
Main Results:
- Formation of discrete rectangles and catenanes through self-assembly.
- Solvent and concentration dependence observed for interlocked structures.
- Confirmation of ligand radical formation in oxidized metallacycles.
- Evidence of exciton coupling in near-infrared ligand radical intervalence charge transfer (IVCT) bands.
Conclusions:
- Successful integration of redox-active nickel salen units into supramolecular metallacycles.
- Demonstration of tunable self-assembly leading to diverse architectures.
- Detailed characterization of the electronic properties and stability of oxidized species, revealing ligand radical character.
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