https://doi.org/10.1351/goldbook.E01886
Intramolecular
strain
present due to nonbonded interactions
between two eclipsed
atoms or groups. It is, for example, one of the interactions responsible for the existence of a rotational barrier
and hence restricted rotation
about the C–C bond in ethane. It has also been called Pitzer strain, torsional strain and bond opposition strain.