Scanning Tunneling Spectroscopy in an Ionic Liquid

摘要

In this communication,we report,for the first time,the application of an ionic liquid,1-butyl-3-methylimidazoliumhexafluoro-phosphate(BMI),as an electrochemical gate medium for tunneling spectroscopy at the single-molecule scale.In a proof-of-principle experiment,we use the Os(II)/Os(III)redox transition of a hetero-leptic redox-active Os bisterpyridine complex(Ossac)to achieve tunneling current modulation at room temperature.One terpy-ridine ligand is functionalized with a 6-acetylthiohexyloxy linker to achieve efficient binding to Au(111)electrode surfaces.The surface redox potential of Ossac is determined by monolayer cyclic voltammetry(CV)(Figure 1).The black CV was measured in aqueous 0.1 M HClO_4.