Bond rotations

[Kellylin_4D]

If single bonds can rotate, and double bonds can’t rotate, do resonance rotate?

[Sahil Jog 1F]

I would assume that resonance structures would not rotate, since their electrons are still delocalized throughout the molecule, which expresses a similar 3 dimensional structure as a double bond (1 sigma and 1 pi bond), and thus not allowing for rotation.

[605208780]

When one or more lewis diagram can be drawn, the molecule is said to have resonance. Resonance isn't about the rotation of bonds, but about the delocalization of electrons that contribute to the overall structure. The idea that resonances rotate isn't really valid.

[Blake Ballew 1H]

What exactly makes single bonds capable of rotation and double bonds unable to do so?

[keely_bales_1f]

What exactly makes single bonds capable of rotation and double bonds unable to do so?

I definitely would rewatch Lavelle's Week 7 Friday Lecture (11/20/20). He draws out sigma and pi bonds and does a demonstration with a pencil that explains why double bonds are incapable of rotating. I have attached my notes of this part of the lecture below if you don't have the time to rewatch Lavelle's lecture. However I highly recommend rewatching this part of the lecture because Lavelle does a great job explaining it in a way that helps you visualize what is happening. Hope this helps you!

[Nina Tartibi 1F]

I don't believe that resonance structures would rotate, because there is still a delocalized electron that makes the double bond in resonance structures. Therefore, with that pi-bond in the double bond, it would restrict the molecule from rotating.

[Inderpal Singh 2L]

I don't believe that resonant bonds can rotate.

[205323697]

Isnt this why we draw a circle in Benzene?

[405509920]

Because of the delocalized pi-bond in resonance structures there would be no rotation. Think of it like an ultimatum: no pi-bonds whatsoever for there to be rotation

[605721741]

Resonance bonds do not rotate!

[305607822]

Yeah resonance bonds don't rotate.