Catalysis of Radical Coupling Reaction via Synergistic Action of Oriented External Electric Field and Light Irradiation
Abstract
Abstract Radical coupling reactions have been widely used in the synthesis of complex organic molecules, materials science, and drug research. However, restricted conditions or special catalysts are required to overcome the energy barrier and trigger the coupling reaction efficiently. In this study, we provide experimental evidence that the C─N radical coupling reactions can be significantly accelerated by an oriented external electric field (OEEF) under synchronous UV irradiation without a catalyst. By repeatedly forming thousands of single‐molecular junctions with reactant molecules in nonpolar solvents under a bias voltage, a new conductance plateau was observed upon UV irradiation, which was completely absent in polar solvents owing to the electrical shielding effect. This finding indicates that the radicals generated under light irradiation can timely participate in the coupling reaction under the in situ action of OEEF, leading to the high‐efficiency generation of the C─N radical coupling product, which was confirmed by the measured electron paramagnetic spectrum and high‐resolution mass spectrometry. With the assistance of theoretical calculations, the underlying mechanism was further revealed, i.e., OEEF can significantly decrease the reaction barrier and facilitate the intermolecular hydrogen atom transfer (HAT). This study provides a catalyst‐free paradigm for high‐efficiency radical reactions.
Article Details
Authors (11)
Hefa Feng
Institute of Modern Optics, Center of Single-Molecule Sciences, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology
Fenglu Hu
Institute of Modern Optics, Center of Single-Molecule Sciences, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology
Xin Zuo
Institute of Modern Optics, Center of Single-Molecule Sciences, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology
Haoyu Wang
Ramya Emusani
Institute of Modern Optics and Center of Single‐Molecule Science Tianjin Key Laboratory of Micro‐scale Optical Information Science and Technology Nankai University Tianjin 300350 China
Guangwu Li
Center of Single-Molecule Sciences, Institute of Modern Optics, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering
Weiwei Niu
Center of Single-Molecule Sciences, Institute of Modern Optics, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
Adila Adijiang
Institute of Modern Optics, Center of Single-Molecule Sciences, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology
Wanghong Deng
Institute of Modern Optics, Center of Single-Molecule Sciences, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology
Lichuan Chen
College of Materials & State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & IKKEM
Dong Xiang
Institute of Modern Optics, Center of Single-Molecule Sciences, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology