Scanning tunneling spectroscopy of C-36

The local density of electronic states N(E) has been measured on C-36 thin films using scanning tunneling spectroscopy(STS). A 0.8 eV energy gap and s harp features in N(E) with widths as small as 0.2 eV can be ascribed to the discrete molecular energy levels predicted for the C-36 molecule, broadene d by intermolecular interactions. However, a more complete agreement betwee n the experimental results and theoretical predictions occurs if the system is modeled as covalently bonded C-36 dimers and trimers. These results con firm the molecular nature of C-36 as well as its higher reactivity as compa red to larger size fullerenes. [S0031-9007(98)08156-3].