Conformational gating of single-molecule conductance in crown ether junctions by Li+ coordination

Abstract

Herein, we report the Li⁺-induced modulation of single-molecule conductance in a crown ether derivative using the scanning tunnelling microscope break junction (STM-BJ) technique. Upon Li⁺ coordination, the conductance decreases from 10^−3.7G₀ to 10^−4.2G₀. Experimental results reveal that the conductance decrease arises from a coordination-induced conformational transition, which extends the molecular junction and weakens the molecule–electrode coupling. These findings establish a clear structure–conductance correlation in crown ether systems and provide insights into the design of ion-responsive molecular electronic devices.