Tube and Cage C60H60: A Comparison with C60F60

Tube C60H60 (5) with fused five-membered rings is more stable than the cage isomer (1) with isolated five-membered rings. Introduction of endo C−H bonds into structure 5 results in further stabilization, but the most stable tube structure with four endo C−H bonds (7) is higher in energy than the most stable cage structure with ten endo C−H bonds (3) by 74.2 kcal/mol. A comprehensive comparison of C60H60 with C60F60 has been made.