Answer and Explanation:
The relationship between the given molecules can be described as follows:
1. Meso Compound:
A meso compound is a stereoisomer that possesses an internal plane of symmetry. Although meso compounds may contain stereocenters, they are not chiral because they have an internal mirror image that cancels out the chirality. Meso compounds are not identical to other molecules on the list because they have a specific characteristic of internal symmetry.
2. Identical Molecules:
Identical molecules are exactly the same in terms of their chemical structure and properties. This means that they have the same connectivity and arrangement of atoms. Identical molecules are the same molecule and not different from each other in any way.
3. Conformational Isomers:
Conformational isomers are different spatial arrangements of the same molecule due to rotation around single bonds. Conformational isomers do not involve changes in connectivity or the presence of different functional groups.
4. Constitutional Isomers:
Constitutional isomers, also known as structural isomers, are different molecules with the same molecular formula but different connectivity. They have different arrangements of atoms and can possess different functional groups.
5. Diastereomers:
Diastereomers are stereoisomers that are not mirror images of each other and have different configurations at one or more stereocenters. Unlike enantiomers, which are discussed next, diastereomers do not possess overall mirror symmetry.
6. Enantiomers:
Enantiomers are mirror-image stereoisomers that are non-superimposable. They have identical connectivity but differ in their spatial arrangement, specifically at all chiral centers. Enantiomers have opposite configurations at every chiral center and exhibit different optical activity.
To summarize, the relationship between the given molecules involves various types of isomers: meso compounds, identical molecules, conformational isomers, constitutional isomers, diastereomers, and enantiomers. Each of these terms represents a specific relationship or characteristic between the molecules.