Direct observation of hindered eccentric rotation of an individual molecule:: Cu-phthalocyanine on C60 -: art. no. 033404

Individual Cu-phthalocyanine molecules have been investigated by scanning tunnel microscopy on a closed packed film of C-60 at various temperatures. The molecules are found to bind asymmetrically to one C-60. While they remain in one position at low temperature, they can hop between six equivalent positions at higher temperatures performing a hindered eccentric rotation around the binding C-60 molecule. At room temperature only the time average over different positions is observed.