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[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
ConPET-Driven Aryl Halide Reduction with a Donor-Acceptor-Donor Anion Radical
Abul Mansur Muhammed Fahim1, Habtom B Gobeze1, Kanyashree Jana1
1Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas78249, United States.
Journal of the American Chemical Society
|August 12, 2026
Summary
This study shows that the TBT anion radical acts as a potent photosensitizer for consecutive photoinduced electron transfer reactions. It efficiently reduces aryl halides under visible light, demonstrating its potential in organic synthesis.
Area of Science:
- Photochemistry
- Organic Electronics
- Materials Science
Background:
- Donor-acceptor-donor molecules are crucial in photochemistry.
- Photosensitizers drive electron transfer reactions.
- Understanding excited states is key to designing new catalysts.
Purpose of the Study:
- Investigate the 4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TBT) anion radical as a photosensitizer.
- Elucidate its role in consecutive photoinduced electron transfer (conPET) reactions.
- Determine its potential as a visible light mediator for aryl halide reduction.
Main Methods:
- Femtosecond transient absorption spectroscopy to measure excited state lifetime.
- Cyclic voltammetry and E00 analysis to determine excited state potential.
- 19F-NMR and HPLC to monitor model reduction reactions.
Main Results:
- The TBT anion radical (TBT-•) exhibits a doublet excited state lifetime of 250 ± 6 ps.
- Its excited state potential was determined to be -2.80 V vs SCE, confirmed by Rehm-Weller analysis.
- TBT-• effectively mediated visible light reduction of aryl bromides via conPET.
Conclusions:
- The TBT anion radical is a powerful, strongly reducing photosensitizer.
- It facilitates visible light-driven aryl halide reduction through a conPET mechanism.
- This highlights its utility in synthetic organic chemistry and photocatalysis.
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