Why can geometric isomers occur?

1 Answer
Jul 8, 2016

Because of restricted rotation about a double bond.

Explanation:

if a compound only has single bonds then, ignoring any steric effects (ie due to the size of a group) geometric isomers are not possible because you simply rotate the isomer back to the original configuration. A double bond does not permit rotation about the axis and therefore the four groups around the C=C centre can be arranged in 2 ways provided there is more than one different group.