Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic devices.However,designing an all-electrically-driven molecular switch is a great challen...Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic devices.However,designing an all-electrically-driven molecular switch is a great challenge.Here,we experimentally and theoretically investigated the charge transport characteristics of isoindigo(ISO)-molecules at the single-molecule level using the scanning tunneling microscope break junction technique.We find that the single-molecule junctions of ISO-molecules display bias voltage-driven switching characteristics.These switches are realtime,reversible,and nondestructive under low-bias voltages.Experimental results show that the mechanism of the switch is not the transition from nonresonant charge transport to resonant charge transport,but it is the shift of the frontier orbital energy levels of ISO-molecules and the change of the interfacial electronic coupling with bias voltage.Our results will advance the design of high-performance bias voltage-driven molecular switches.展开更多
To monitor and investigate chemical reactions in real time and in situ is a long-standing,challenging goal in chemistry.Herein,an electric potential-promoted oxidative coupling reaction of organoboron compounds withou...To monitor and investigate chemical reactions in real time and in situ is a long-standing,challenging goal in chemistry.Herein,an electric potential-promoted oxidative coupling reaction of organoboron compounds without the addition of base is reported,and the transmetallation process involved is monitored in real time and in situ with the scanning tunneling microscopy break single-molecule junctions(STMBJ)technique.We found that the electric potential applied determined the transmetallation.At low-bias voltage,the first-step transmetallation process occurred and afforded Au─C-bonded aryl gold intermediates.The electronic properties of organoboron compounds have a strong influence on the transmetallation process,and electron-rich compounds facilitate this transformation.At high-bias voltage,the second-step transmetallation process took place,and the corresponding intermediate(highly reactive diaryl metal complex)was detected with the assistance of Pd(OAc)_(2).Our work demonstrates the applications of STMBJ on in situ monitoring and catalyzing of chemical reactions and provides a new methodology to fabricate singlemolecule devices.展开更多
基金supported by the National Natural Science Foundation of China(grant nos.21875279,22075080,and 52273176)the Shanghai Municipal Science and Technology Major Project(grant no.2018SHZDZX03)the Fundamental Research Funds for the Central Universities,and East China University of Science and Technology.
文摘Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic devices.However,designing an all-electrically-driven molecular switch is a great challenge.Here,we experimentally and theoretically investigated the charge transport characteristics of isoindigo(ISO)-molecules at the single-molecule level using the scanning tunneling microscope break junction technique.We find that the single-molecule junctions of ISO-molecules display bias voltage-driven switching characteristics.These switches are realtime,reversible,and nondestructive under low-bias voltages.Experimental results show that the mechanism of the switch is not the transition from nonresonant charge transport to resonant charge transport,but it is the shift of the frontier orbital energy levels of ISO-molecules and the change of the interfacial electronic coupling with bias voltage.Our results will advance the design of high-performance bias voltage-driven molecular switches.
基金This work was supported by the National Natural Science Foundation of China(grant nos.21875279,21790362,and 22075080)the Shanghai Municipal Science and Technology Major Project(grant no.2018SHZDZX03)+1 种基金the Fundamental Research Funds for the Central Universities,the Programme of Introducing Talents of Discipline to Universities(grant no.B16017)the Program of Shanghai Academic/Technology Research Leader(grant no.19XD1421100).
文摘To monitor and investigate chemical reactions in real time and in situ is a long-standing,challenging goal in chemistry.Herein,an electric potential-promoted oxidative coupling reaction of organoboron compounds without the addition of base is reported,and the transmetallation process involved is monitored in real time and in situ with the scanning tunneling microscopy break single-molecule junctions(STMBJ)technique.We found that the electric potential applied determined the transmetallation.At low-bias voltage,the first-step transmetallation process occurred and afforded Au─C-bonded aryl gold intermediates.The electronic properties of organoboron compounds have a strong influence on the transmetallation process,and electron-rich compounds facilitate this transformation.At high-bias voltage,the second-step transmetallation process took place,and the corresponding intermediate(highly reactive diaryl metal complex)was detected with the assistance of Pd(OAc)_(2).Our work demonstrates the applications of STMBJ on in situ monitoring and catalyzing of chemical reactions and provides a new methodology to fabricate singlemolecule devices.
