Butane’s Anti, Gauche, and Eclipsed Forms

Butane has several conformations, or shapes made by rotation around a carbon-carbon bond. Unlike ethane and propane, which have only two major conformations, butane shows more than two conformers.

The lowest-energy form is the staggered anti conformer. In this shape, the two bulky methyl groups s...

In butane, rotations about the central carbon-carbon bond generate different conformations of the molecule. The conformers, when viewed along the C2–C3 bond, show the various Newman projections.

Energy changes that result from the C2–C3 bond rotations generate several staggered and eclipsed conformations of butane, with varying dihedral a...