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.