Revealing Supramolecular Interactions And Electron Transport In Single Molecular Junctions Of Cucurbit[N]Uril

Probing binding interaction and electron transport of supramolecules bridging metal electrodes are crucial to the design and construction of supramolecular electronic devices. Herein, scanning tunneling microscope break junction technique is employed to form single molecular junctions of cucurbit[n]uril (CB[n]) and their conductance is measured. It is found that the electrostatic interactions of the carbonyl portals contribute to form the molecular junctions of CB[n] family. As the number of the terminal carbonyl groups increases, the single-molecule conductance linearly decreases as CB[5] > CB[6] > CB[7], which arise from the different interfacial coupling. This conductance order is also further confirmed by calculated energy-dependent transmission coefficient T(E). The present work provides a single-molecule level picture of supramolecular interactions and electron transport of CB[n] for the future design of nanodevices using supramolecular assemblies.