Ethane-1,2-diol, also known as ethylene glycol, has the molecular formula HO–CH₂–CH₂–OH. It exhibits different conformations due to rotation around the C–C single bond.
Important Conformations
- Gauche Conformation: The two –OH groups are separated by a dihedral angle of approximately 60°.
- Anti Conformation: The two –OH groups are separated by a dihedral angle of 180°.
- Eclipsed Conformation: The bonds on the front and rear carbon atoms overlap when viewed along the C–C bond.
Most Stable Conformation
The gauche conformation is particularly stable because it allows intramolecular hydrogen bonding between the two –OH groups. The anti conformation does not favour the same intramolecular hydrogen bond, while eclipsed conformations generally have greater torsional strain.
Conclusion: The gauche conformation of ethane-1,2-diol is especially stable due to intramolecular hydrogen bonding between its hydroxyl groups.
Add Newman projection descriptionsClarify the stability comparison
