Direct imaging of Sc2@C84 molecules encapsulated inside single-wall carbon nanotubes by high resolution electron microscopy with atomic sensitivity

Intramolecular structure of the scandium dimetallofullerene (Sc-2@C-84) has been clearly revealed by high resolution transmission electron microscopy with the single-atom sensitivity. Direct observation of two Sc atoms inside each fullerene molecule has led to a successful determination of the molecular symmetry among the three possible structural isomers for the Sc-2@C-84. The present work introduces a new electron microscopic approach to investigate individual molecular structures and demonstrates the possibility for determining the molecular isomer on a single-molecular basis.