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![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
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[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
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Solvent Dependency of Catalyst-Substrate Aggregation Through π-π Stacking in Photoredox Catalysis
Luke Wylie1, Joshua P Barham2, Barbara Kirchner1
1University of Bonn, Clausius Institute of Physical and Theoretical Chemistry, Mulliken Center for Theoretical Chemistry, Beringstr. 4, D-53115, Bonn, Germany.
Summary
Photocatalyst-substrate assemblies form via π-stacking interactions, influencing reactivity. Solvents like MeCN promote these assemblies, enhancing photocatalytic reactions, while DMF hinders them.
Area of Science:
- Photochemistry
- Catalysis
- Supramolecular Chemistry
Background:
- Pre-photoexcitation assemblies of photoredox catalysts and substrates are often overlooked.
- These non-covalent assemblies can significantly impact reactivity and selectivity in photocatalysis.
Purpose of the Study:
- To investigate the aggregation states of triarylamine radical cationic photocatalysts with arene substrates.
- To elucidate the role of solvents in mediating catalyst-substrate assembly formation and stability.
- To determine the dynamic behavior and lifetimes of these assemblies in solution.
Main Methods:
- Specifically parameterized polarizable molecular dynamics (MD) simulations were employed.
- Investigated interactions between triarylamine radical cations and arene substrates.
- Analyzed solvent effects (acetonitrile vs. dimethylformamide) on assembly formation.
Main Results:
- Confirmed π-stacking interactions between photocatalysts and substrates, consistent with prior quantum calculations.
- Demonstrated that acetonitrile promotes catalyst-substrate assemblies, enhancing reactivity, while dimethylformamide disfavors them.
- Calculated assembly lifetimes exceeding 60 picoseconds in both ground and photoexcited states.
Conclusions:
- Solvent choice critically influences photocatalytic reaction outcomes by controlling catalyst-substrate assembly.
- The observed long-lived assemblies are suitable for intra-assembly electron transfer upon photoexcitation.
- This study provides novel insights into the dynamics of non-covalent assemblies in synthetic photocatalysis.
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