The Case for Steric Repulsion Causing the Staggered Conformation of Ethane

Abstract

The barrier to rotation in ethane (see picture) is considered a prototypical case of steric hindrance. This view has been recently contradicted, and hyperconjugation has been put forward as the right explanation. The authors argue that there is no reason to abandon the steric repulsion explanation, and discuss why different electronic structure analyses yield different views.