## Sigma bonds

$sp, sp^{2}, sp^{3}, dsp^{3}, d^{2}sp^{3}$

Arkinrao3A
Posts: 11
Joined: Wed Sep 21, 2016 2:58 pm

### Sigma bonds

Why is it that there can not be more than one sigma bond, or is there a case where you can have two or more sigma bonds?

Simon Kapler 3I
Posts: 15
Joined: Mon Sep 26, 2016 3:01 am

### Re: Sigma bonds

The hybridization theory of bonding differentiates between sigma and pi bonds based on how they overlap, which depends on their orientation in space. In a sigma bond, two orbitals pointing toward each other (along the internuclear axis) overlap end-over-end, whereas in a pi bond, two parallel orbitals (both perpendicular to the internuclear axis) overlap side-by-side. Since the orbitals of an atom all point in different directions away from the nucleus, there would not be a situation in which two different orbitals from each atom overlapped end-to-end (a sigma bond) between a pair of atoms. Hope this is helpful/makes sense!