Sigma and Pi bonds

[Andrea_Torres]

Can someone please explain to me what are sigma and pi bonds?

[Jiyoon_Hwang_2I]

You can think of sigma bonds as basically a single bond. So, if two atoms have a single bond between them that means it has one sigma bond. On the other hand, every other bond after the single bond is considered a pi bond. For example, a double bond is a sigma bond and 1 pi bond and a triple bond is a sigma bond and 2 pi bonds.

[VLi_2B]

A sigma bond is a bond formed by the overlap of orbitals in an end-to-end fashion, with the electron density concentrated between the nuclei of the bonding atoms.

A pi bond is a bond formed by the overlap of orbitals in a side-by-side fashion with the electron density concentrated above and below the plane of the nuclei of the bonding atoms.

In general, single bonds between atoms are always sigma bonds. Double bonds are comprised of one sigma and one pi bond. Triple bonds are comprised of one sigma bond and two pi bonds.