Sigma bond is a chemical bond formed by the linear or co-axial overlapping of the atomic orbitals of two atoms. A pi bond is a type of covalent bond that exists between atoms where the electrons are on top and bottom of the axis connecting the nuclei of the joined atoms. It is formed by the parallel or lateral overlapping of the atomic orbitals.
Difference Between Sigma and Pi Bond
While sigma and pi bonds are used to describe some features of covalent bonds and molecules, there are significant differences between the two. We will look at some differences between sigma and pi bond below.
| Difference Between Sigma and Pi bond | |
|---|---|
| Sigma Bond | Pi Bond |
| During sigma bond formation overlapping orbitals can either be one hybrid orbital and a single pure orbital, or two pure orbitals and two hybrid orbitals. | During pi bond formation overlapping orbitals must be two unhybridized orbitals. |
| Sigma bonds are known to exist independently and allow free rotation. | Pi-bond must always exist along with sigma bond and the rotation is restricted. |
| Sigma bonds are stronger bonds. | Pi bonds are usually weaker compared to sigma bonds. |
| Sigma bonds are formed first when atoms interact. | Pi bonds between two atoms are formed after sigma bonds are formed between them. |
| During the bonding between two given atoms,Only one sigma bond is formed. | Here two pi bonds can exist between two atoms. |
| Sigma bonds are known to have cylindrical charge symmetry around the axis of the bond. | No symmetry exists in pi bonds. |
| Atoms with sigma bonds are less reactive. | Atoms with pi bonds are highly reactive when compared to those with only sigma bonds. |
| Sigma bond can be used to determine the shapes of molecules. | Pi bond cannot be used for the same purpose. |
These are some differences between Sigma and Pi bond.
