Direct Observation of Distinctive Electronic States and Mechanical Function of Ferrocene Moieties in Ferrocene-bridged Trisporphyrin Using Scanning Tunneling Microscopy/Spectroscopy

Abstract

The mechanical and electronic properties of ferrocene-bridged trisporphyrin, which consists of three porphyrin units bridged via a ferrocene (Fc) moiety, and adsorbed onto Au(111) by a pulse injection method, were investigated using low temperature scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). The electronic states originating from the ferrocene group were clearly observed by bias voltage dependent STM images, as well as by STS. Sequential submolecular resolution STM images and conformational analyses using a simple molecular model revealed that the ferrocene moiety acts as a molecular ball bearing.