Cyclopropyl group

The group has an empirical formula of C3H5 and chemical bonds from each of the three carbons to both of the other two.

Due to the unfavoured bond angles (60°), cyclopropyl groups are highly strained.

Two orbital models were proposed to describe the bonding situation.

Here the two sp-hybrids forming the ring bond are separated into one sp2-hybrid and one pure p-orbital.

Cyclopropyl groups are good donors in hyperconjugation resulting in a considerable stabilization of carbocations.