Tunneling processes within a C₆₀ molecule

A description of the tunneling channels through a C60 molecule is presented with its implications for imaging the internal structure of C60 using scanning tunneling microscopy (STM). The approach of an STM tip from tunneling to mechanical and electrical contact with a C60 molecule adsorbed on a Au(110) surface is characterized using experimental and calculated current-distance parameters. The term 'electrical transparence' is introduced to describe the ability of a molecule in the tip apex-surface nanoscopic cavity to participate in the electron-transfer process. It is influenced both by the mechanics of the tip approach process and the modification of the electronic structure of the molecule interacting with the tip apex and the Au(110) surface in the cavity.