Dihedral angle of least stable conformer of ethane is [2021]
(1)
Dihedral angle of least stable conformer of ethane is 0°. Magnitude of torsional strain depends upon the angle of rotation about C–C bond. This angle is also called dihedral angle or torsional angle. Of all the conformations of ethane, the staggered form has the least torsional strain and the eclipsed form, the maximum torsional strain.