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Sigma and Pi Bonds

Posted: Sat Nov 23, 2019 4:05 pm
by Shannon Asay 1C
Why is a sigma bond more stable than a pi bond?

Re: Sigma and Pi Bonds

Posted: Sat Nov 23, 2019 4:07 pm
by VioletKo3F
The orbitals that form sigma bonds overlap more than the orbitals forming the pi bonds so they are much stronger.

Re: Sigma and Pi Bonds

Posted: Sat Nov 23, 2019 4:14 pm
by Alan Wu
The orbitals forming a sigma bond overlap end to end. Just imagine 2 dumbbells flat on the floor, with one of their ends completely merged together. The orbitals forming a pi bond overlap side to side. Just imagine 2 dumbbells standing side by side on the floor, with each of their ends touching each other. Obviously, there is more overlapping in a sigma bond, so it is stronger than a pi bond.

Re: Sigma and Pi Bonds

Posted: Sat Nov 23, 2019 4:32 pm
by Lizette Noriega 1H
If the orbitals that form sigma bonds overlap more than the pi bonds, how is it that sigma bonds can rotate and have more flexibility than the pi bonds?

Re: Sigma and Pi Bonds

Posted: Sat Nov 23, 2019 4:34 pm
by Alan Wu
Lizette Noriega 1H wrote:If the orbitals that form sigma bonds overlap more than the pi bonds, how is it that sigma bonds can rotate and have more flexibility than the pi bonds?


Sigma bonds overlap in a different way. Use the dumbbell example I mentioned above. If 2 dumbbells are merged together on one end (like orbitals in a sigma bond), you can obviously rotate them. However, if 2 dumbbells are standing side by side with each end touching the other (like orbitals in a pi bond), rotating on dumbbell would cause the ends to detach from the ends of the other dumbbell.

Re: Sigma and Pi Bonds

Posted: Sat Nov 23, 2019 5:49 pm
by RobertXu_2J
The overlap of a pi bond is less than that of a sigma bond. However the sigma bond only overlaps at one area, whereas the pi bond overlaps at two. So because the pi bond overlaps at two areas, it cannot turn and thus keep the molecule in position.

Re: Sigma and Pi Bonds

Posted: Sat Nov 23, 2019 6:16 pm
by Rodrigo2J
Sigma bonds overlap end to end on the same internuclear axis and pi bonds form when the lobe of one atoms orbital overlaps another.