The Shape of Cycloalkanes

The Baeyer strain theory is useful to us in identifying angle strain as a destabilizing effect. Its fundfflnental flaw is its assumption that the rings of cycloalkanes are planar-. With the exception of cyclopropane, cycloalkanes are nonplanar. Sections 3.5-3.13 describe the shapes of cycloalkanes. We ll begin with cyclopropane. 

In the early studies, the cycloalkane holes were viewed as molecular radical cations that undergo rapid resonant charge transfer. At any given time, the positive charge was assumed to reside on a single solvent molecule and, once in 0.5-2 psec, to hop to a neighboring molecule. The low activation energy was explained by the similarity between the shapes of cycloalkane molecules and their radical cations [60]. 

The shape of cycloalkanes is determined by torsional strain, steric strain and angle strain. 

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