How can I determine the equivalence with an axis of rotation?
1 Answer
Any two groups that can be exchanged by a proper axis of rotation are termed equivalent.
Explanation:
To repeat, (and I assume you ask this question on the basis of NMR spectroscopy) any groups that are exchanged by a proper axis of rotation (
On the other hand, any groups that are exchanged by an improper axis of rotation are termed enantiotopic. Nevertheless, in all ACHIRAL environments, enantiotopic nuclei should give rise to the ONE signal. In a chiral environment, for instance a chiral NMR solvent (these do exist), the interaction of the enantiotopic nuclei with the solvent renders these nuclei diastereotopic, and in principle differentiable in the NMR experiment.
The third such category, diastereotopic, refers to groups that are constitutionally equivalent (i.e. their connectivity is the same), yet cannot be interchanged by rotation or reflection. A pair of diastereotopic proton nuclei should thus give rise to 2 separate signals in the
