Ethane's Conformations There barrier to rotation between conformations is small (12 kJ/mol)The most stable conformation of ethane has all six C-H bonds away from each other(staggered) The least stable conformation has all six C-H bonds as close as possible (eclipsed)in a Newman projection- energy due to torsional strain Eclipsed conformers 4.0 kJ/mol HH 八 12 k,J/mol 4.0 kJ/mo 4.0 kJ/mol Ethane-eclipsed conformation Ethane’s Conformations „ There barrier to rotation between conformations is small (12 kJ/mol) The most stable conformation of ethane has all six C–H bonds away from each other (staggered ) „ The least stable conformation has all six C–H bonds as close as possible (eclipsed) in a Newman projection – energy due to torsional strain