Tube and Cage C<sub>60</sub>H<sub>60</sub>: A Comparison with C<sub>60</sub>F<sub>60</sub>

Tube C<sub>60</sub>H<sub>60</sub> (<b>5</b>) with fused five-membered rings is more stable than the cage isomer (<b>1</b>) with isolated five-membered rings. Introduction of <i>endo</i> C−H bonds into structure <b>5</b> results in further stabilization, but the most stable tube structure with four <i>endo</i> C−H bonds (<b>7</b>) is higher in energy than the most stable cage structure with ten <i>endo</i> C−H bonds (<b>3</b>) by 74.2 kcal/mol. A comprehensive comparison of C<sub>60</sub>H<sub>60</sub> with C<sub>60</sub>F<sub>60</sub> has been made.