Organic Chemistry
Conformations (Conformational Isomerism)
Differences in atom arrangements due to the rotations of single bonds (does not have to be C-C bonds,
but usually will be)
There is a barrier for this to occur, but its so small in energy that the molecule can get over this easily
many times per second
Ex. Ethane – the C-C bond can rotate easily
Staggered conformation:
Eclipsed conformation – poorer (higher in energy by 12kJ/mol):
The eclipsed conformation is higher in energy because the electrons in the filled C-H σ bonding orbitals
repel each other = tortional strain
If we keep rotating:
Conformations (Conformational Isomerism)
Differences in atom arrangements due to the rotations of single bonds (does not have to be C-C bonds,
but usually will be)
There is a barrier for this to occur, but its so small in energy that the molecule can get over this easily
many times per second
Ex. Ethane – the C-C bond can rotate easily
Staggered conformation:
Eclipsed conformation – poorer (higher in energy by 12kJ/mol):
The eclipsed conformation is higher in energy because the electrons in the filled C-H σ bonding orbitals
repel each other = tortional strain
If we keep rotating:
