What is the relationship between the structures depicted below?
Show Hint
When dealing with Newman or Sawhorse projections, always check if a simple rotation of one or both carbons around the central \(\text{C}-\text{C}\) bond can match the configurations.
If yes, the relationship is always conformational isomers.
To determine the relationship between the structures depicted in the image, let's analyze the characteristics of each option given:
Conformational Isomers: Conformational isomers are stereoisomers that can be interconverted by rotation around single bonds. These isomers typically involve different spatial orientations that are accessible through rotation around the sigma bonds without breaking any bonds.
Structural Isomers: Also known as constitutional isomers, these are isomers that have the same molecular formula but different connectivity of atoms in the molecule, essentially different bonding arrangements.
Enantiomers: These are a type of stereoisomer that are non-superimposable mirror images of each other, generally involving chiral centers where the spatial arrangement around the center is different.
Positional Isomers: Positional isomers have the same molecular formula but differ in the position of the functional group or substituent on the parent chain.
Now, let's inspect the structures:
The two structures shown have the same molecular formula and connectivity but differ in spatial orientation due to rotation around a single bond.
The C–C bond revolutions cause differences in the orientation of groups attached to the carbons in terms of staggered and eclipsed formations.
This is a classic example of conformational isomerism, where two isomers can be interconverted freely with simple rotations, usually visualized as Newman projections.
Given that the two structures differ purely by rotation around single bonds and do not differ in connectivity or configuration, the correct classification is Conformational isomers.
