Conformational isomerism concerns spatial arrangements interconverted by internal motion, such as turning about a single chemical bond. Moving the entire molecule or applying a rotation changes its position or viewing direction, not its internal arrangement.
A conformational form distinguished by rotation about a specified bond. Interconversion can be slow when resonance gives that bond partial multiple-bond character.
Antiperiplanar geometry places two specified bonds at a torsion near . It often enables favorable orbital alignment in E2 elimination and supports large vicinal proton couplings in an appropriate calibrated Karplus relation.
A gauche interaction concerns groups separated by an approximately torsion about a bond. Its energetic effect depends on the groups and electronic environment; not every gauche geometry is unfavorable.
Ring inversion interconverts ring conformations while preserving covalent connectivity and configurational stereochemistry. In a cyclohexane chair flip, axial and equatorial labels exchange, while the up/down face of a given substituent is retained.
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Conformational isomerism, also known as conformers or conformational isomers, refers to the different spatial arrangements of a molecule that can be achieved by rotation around single bonds. Unlike structural isomers, which differ in the connectivity of atoms, conformational isomers differ only in their three-dimensional shapes due to the rotation around single sigma (σ) bonds.