Tube and Cage C₆₀H₆₀: A Comparison with C₆₀F₆₀

Abstract

Tube C₆₀H₆₀ (<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 C₆₀H₆₀ with C₆₀F₆₀ has been made.