117.

Define the terms conformation and conformational isomerism.

The conformation of a molecule refers to different three-dimensional positions of atoms or groups relative to each other, arising from rotation about single (σ) bonds. The energy required for rotation about C-C bond or a bond is very low and such rotations usually occur readily. So, the various conformations of a molecule are freely interconvertible. This phenomenon of getting different conformations arising from rotation about a single or sigma bond is called conformational isomerism.