Difference Between Sigma and Pi bond

The primary differences between sigma and pi bonds lie in their formation and strength. Sigma bonds are created by the direct head-to-head overlap of orbitals, whereas pi bonds are formed by the side-to-side overlap, typically between p orbitals. This distinct formation method results in varying bond strengths. Sigma bonds are stronger than pi bonds because the direct head-to-head overlap leads to a larger and more robust overlap compared to the side-to-side overlap of pi bonds. Moreover, sigma bonds form single bonds and can exist independently, while pi bonds require the presence of an existing sigma bond to form.