Quasi-Continuous Efficient Regulation of Single-Molecule Electronic Distribution.

The electronic distribution characteristics of molecules significantly influence the charge transport properties and the device performance of molecular electronic devices. These characteristics are closely related to subtle molecular structures, forming a formidable challenge for effective control. Here, a flexible crown ether moiety is integrated into the single-molecule junction, where its spatial structure can be regulated by an external electric field, enabling efficient tuning of the electronic characteristics. It is found that the transformation barriers between different structures and the conductance of single-molecule junctions can be adjusted by the external electric field. Both theoretical and experimental results consistently demonstrate that the interaction between the external electric field and the intrinsic molecular dipole can alter the molecular energy and stabilize a series of metastable molecular configurations, allowing for the quasi-continuous manipulation of the electronic characteristics. This study unveils efficient control of the single-molecule electronic characteristics by external electric fields, advancing a deeper understanding of molecular electronics and supramolecular chemistry.