Pi Bonds Cannot Rotate


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Inderpal Singh 2L
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Pi Bonds Cannot Rotate

Postby Inderpal Singh 2L » Wed Dec 02, 2020 1:25 pm

Why can Pi Bonds not Rotate? I cannot visualize it properly.

Leo Naylor 2F
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Re: Pi Bonds Cannot Rotate

Postby Leo Naylor 2F » Wed Dec 02, 2020 1:27 pm

Pi bonds cannot rotate because they are p-orbitals overlapping side-by-side, so that both electron density areas are "touching." Hope this helps.

Jagveer 1I
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Re: Pi Bonds Cannot Rotate

Postby Jagveer 1I » Wed Dec 02, 2020 1:32 pm

To add on, for the molecule to rotate about the double bond, the π-bond would need to break and then reform. It is not possible for a π-bond to remain intact and rotate.

SahajDole_1C
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Re: Pi Bonds Cannot Rotate

Postby SahajDole_1C » Wed Dec 02, 2020 1:48 pm

Pi bonds cannot rotate because the p orbitals overlap and cause a double bond which is more stronger and thus it cannot rotate

Melis Kasaba 2B
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Re: Pi Bonds Cannot Rotate

Postby Melis Kasaba 2B » Wed Dec 02, 2020 2:48 pm

For a pi bond, there has to be a parallel orientation of the p orbitals so they overlap. If the bond were to rotate, that would break it.

BKoh_2E
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Re: Pi Bonds Cannot Rotate

Postby BKoh_2E » Wed Dec 02, 2020 5:05 pm

Here is an image that may help you visualize it!

Image

105618850
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Re: Pi Bonds Cannot Rotate

Postby 105618850 » Thu Dec 03, 2020 1:54 am

Pi bonds overlap parallel to one another meaning that rotation is not possible. If there was any form of rotation, the bond would be broken as a result.

Navdha Sharma 3J
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Re: Pi Bonds Cannot Rotate

Postby Navdha Sharma 3J » Thu Dec 03, 2020 5:23 am

Pi-bonds overlap side-by-side. If they rotate, they will break. Hence, pi bonds do not rotate.

Annette Fishman
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Re: Pi Bonds Cannot Rotate

Postby Annette Fishman » Thu Dec 03, 2020 12:34 pm

Rotation around a single bond occurs readily, while rotation around a double bond is restricted. The pi bond prevents rotation because of the electron overlap both above and below the plane of the atoms.

Jason Knight - 1F
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Re: Pi Bonds Cannot Rotate

Postby Jason Knight - 1F » Thu Dec 03, 2020 1:23 pm

Pi bonds are present in double and triple bonded molecules. For example, a double bond has one pi bond and a triple bond has two pi bonds. Pi bonds cannot rotate because that would require the break of the parallel orientation of the p-orbitals.

apurva-3E
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Re: Pi Bonds Cannot Rotate

Postby apurva-3E » Thu Dec 03, 2020 1:46 pm

They cannot rotate because there are p orbitals overlapping side by side. Try to visualize this in your head after looking at a picture of the pi bond.

David Y
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Re: Pi Bonds Cannot Rotate

Postby David Y » Sun Dec 06, 2020 4:24 pm

if the bond were to rotate it would break because they are parallel

Chance Herbert 3A
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Re: Pi Bonds Cannot Rotate

Postby Chance Herbert 3A » Sun Dec 06, 2020 4:43 pm

I remember in Dr. Lavelle's lecture on types of bonds he held a marker in his hands parallel to demonstrate how pi bonds do not allow for rotation. If rotation were to occur, the bond would have to be broken which was represented by the marker falling from his hands. I am totally visual as well and I feel like this video gives a great representation if you are still struggling! Hope this helps! https://www.youtube.com/watch?v=7tH8Xe5u8A0
Last edited by Chance Herbert 3A on Sun Dec 06, 2020 4:49 pm, edited 1 time in total.

Tatyana Bonnet 2H
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Re: Pi Bonds Cannot Rotate

Postby Tatyana Bonnet 2H » Sun Dec 06, 2020 4:48 pm

They don't rotate because they are connected side by side, if one atom were to rotate they would no longer be side to side breaking the pi bond. Therefore, pi bonds keep a structure in its plane unless broken.

Joel Meza 3I
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Re: Pi Bonds Cannot Rotate

Postby Joel Meza 3I » Sun Dec 06, 2020 5:24 pm

Image
This picture does a pretty good job at showing how a pi bond would break.

Nathaly Cruz 2D
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Re: Pi Bonds Cannot Rotate

Postby Nathaly Cruz 2D » Sun Dec 06, 2020 5:53 pm

When rotating, would the pi bond break because it is no longer parallel?

Caelin Brenninkmeijer 1G
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Re: Pi Bonds Cannot Rotate

Postby Caelin Brenninkmeijer 1G » Sun Dec 06, 2020 6:01 pm

Nathaly Cruz 2D wrote:When rotating, would the pi bond break because it is no longer parallel?

Correct! Pi bonds don't allow atoms to rotate, so if the atom is no longer parallel, there is no pi bond. This is because pi bonds have electron densities on each side of the internuclear axis, preventing the bond to exist if the atoms bonded are not 180º.

David Facio 1K
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Re: Pi Bonds Cannot Rotate

Postby David Facio 1K » Sun Dec 06, 2020 6:06 pm

Think of it like the base you make when you lock arms with another person to give your friend a boost over a fence. If one of the persons serving as the base tried rotating their arms, it would be less stable, and under pressure, the base would break. Similarly, Pi bonds can't rotate, or else they'd simply break.

LovepreetSran_3H
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Re: Pi Bonds Cannot Rotate

Postby LovepreetSran_3H » Sun Dec 06, 2020 6:10 pm

Pi-bonds overlap in a parallel, making it unable to rotate.

Hannah Lechtzin 1K
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Re: Pi Bonds Cannot Rotate

Postby Hannah Lechtzin 1K » Sun Dec 06, 2020 6:20 pm

Pi bonds rely on two p orbitals overlapping side by side. Think of two figure eights overlapping long side to long side. If one of those two figure eights were to turn, then they would no longer overlap side to side. If this occurs with two p-orbitals the bond breaks so pi bonds cannot rotate.

Gian Boco 2G
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Re: Pi Bonds Cannot Rotate

Postby Gian Boco 2G » Sun Dec 06, 2020 10:18 pm

In a pi bond orbitals are overlapping outside of the intermolecular axis. Thus, rotating the bond about that axis would break the pi bond. On the other hand, sigma bonds overlap along this axis and thus allowing rotation.

Charlie Russell 2L
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Re: Pi Bonds Cannot Rotate

Postby Charlie Russell 2L » Sun Dec 06, 2020 10:23 pm

The two p-orbitals overlap. Think of a LADDER. You cannot move 1 ring of the ladder without moving the other unless you break it (the bond breaks).

Nathaly Cruz 2D
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Re: Pi Bonds Cannot Rotate

Postby Nathaly Cruz 2D » Wed Dec 16, 2020 6:46 pm

Caelin Brenninkmeijer 1H wrote:
Nathaly Cruz 2D wrote:When rotating, would the pi bond break because it is no longer parallel?

Correct! Pi bonds don't allow atoms to rotate, so if the atom is no longer parallel, there is no pi bond. This is because pi bonds have electron densities on each side of the internuclear axis, preventing the bond to exist if the atoms bonded are not 180º.


Thank you for the explanation :)

America Ramirez 3H
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Re: Pi Bonds Cannot Rotate

Postby America Ramirez 3H » Thu Dec 17, 2020 8:36 am

you basically have two regions of the p-orbital overlapping and you cant rotate one without rotating another and thus breaking the pi bond.


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