Chapter 5: Stereochemistry of Confined Molecules

The translational consequence of molecular encapsulation is fairly obvious: the guest molecule's entropy is reduced as a result of its confinement in a small space. But what about its other motions — spinning, tumbling, internal rotations and vibrations? While there is never a fit between host and guest that is snug enough to effectively alter vibrations, we will see that other internal motions such as sigma bond rotations can be profoundly affected and result in otherwise unknown contorted conformations.