The following are the differences between sigma and pi-bonds:
Sigma (σ) Bond Pi (π) Bond
(a) It is formed by the end to end overlap of orbitals. It is formed by the lateral overlap of orbitals.
(b) The orbitals involved in the overlapping These bonds are formed by the overlap of p–p orbitals only.
are s–s, s–p, or p–p.
(c) It is a strong bond. It is weak bond.
(d) The electron cloud is symmetrical about The electron cloud is not symmetrical.
the line joining the two nuclei.
(e) It consists of one electron cloud, which is There are two electron clouds lying above and below the plane of
symmetrical about the internuclear axis. the atomic nuclei.
(f) Free rotation about σ bonds is possible. Rotation is restricted in case of pi-bonds.
