The boat conformation

So far we didn't meet the boat conformation yet. It doesn't appear in the interconversion process that we animated.
Like the half-chair, it is an energy maximum: it is a low lying transition state (much lower than the half-chair!) between two twist-boat structures.

Use these animation control buttons, or click on a red dot in the graph. Select two atoms to measure distance Select three, to measure angle Select four, to measure torsion angle

Note the very low energy barrier. So in fact all the possible chairs, and all twist-boat minima, are connected via these pathways.
Don't get the idea that one chair always moves straight to the 'other' chair: a twist-boat intermediate can move 'sideways' to another twist-boat, and another one, and from there select any other route. The result is a continuously 'wobbling' cyclohexane ring.

A point to philosophize:
Talking about symmetry: what is the symmetry of the boat conformation? If we distinguish between all the atoms (e.g. number them), how many different boat structures can we draw? How many different chairs? How many different twist-boats?

Energies are from AM1 calculations and are for qualitative discussion only. Better calculations would give different quantitative results. This page was adapted by Bob Hanson for Internet Explorer 4 and Netscape 7 from the original, written by Hens Borkent