Delocalized Pi Bond

(Polar molecules, Non-polar molecules, etc.)

Moderators: Chem_Mod, Chem_Admin

Seraphina Joseph 1C
Posts: 102
Joined: Wed Sep 30, 2020 9:31 pm

Delocalized Pi Bond

Postby Seraphina Joseph 1C » Wed Nov 25, 2020 3:17 pm

What makes a Pi bond delocalized and how do you determine if a pi bond is regular or delocalized?

Isabelle Hales 1J
Posts: 91
Joined: Wed Sep 30, 2020 9:41 pm
Been upvoted: 1 time

Re: Delocalized Pi Bond

Postby Isabelle Hales 1J » Wed Nov 25, 2020 3:35 pm

A delocalized pi bond occurs in molecules that have resonance structures. When the double bond can occur in more than one place, the atoms bind in such a way that they share electrons, causing the bonds to be in between single and double. When this occurs, the pi bond is delocalized because it is not in one specific place. For example, in Benzene (C6H6), the 6 carbons in the middle ring have 3 double bonds spread out with amongst them. However, because Benzene has resonance structures, the electrons will be shared between all 6 carbons, leading to 3 delocalized pi bonds.

Anh Trinh 1J
Posts: 147
Joined: Wed Sep 30, 2020 9:55 pm
Been upvoted: 1 time

Re: Delocalized Pi Bond

Postby Anh Trinh 1J » Thu Nov 26, 2020 8:24 pm

A delocalized pi bond is only present in molecules with resonance structures. For example, have resonance structures. There is a single bond and a double bond in , but the double bond can be on either of the O atoms, so the molecule has two resonance structures. This means that this molecule has a delocalized pi bond because the pi orbitals extend over more than two atoms.

Seraphina Joseph 1C
Posts: 102
Joined: Wed Sep 30, 2020 9:31 pm

Re: Delocalized Pi Bond

Postby Seraphina Joseph 1C » Sat Nov 28, 2020 1:56 pm

I get it now! thank you so much

Madison Muggeo 3H
Posts: 95
Joined: Wed Sep 30, 2020 9:35 pm

Re: Delocalized Pi Bond

Postby Madison Muggeo 3H » Sat Nov 28, 2020 2:57 pm

This post was so helpful, I had a similar question. Thank you to all that responded!

Simi Kapila_3E
Posts: 90
Joined: Wed Sep 30, 2020 9:40 pm
Been upvoted: 1 time

Re: Delocalized Pi Bond

Postby Simi Kapila_3E » Sat Nov 28, 2020 3:00 pm

Delocalized pi bonds occur when a structure has resonance. They are considered delocalized because they do not have a single permanent location, due to the fact that the actual molecule is usually a mix of the resonance structures.

Lilly Catarozoli 1B
Posts: 109
Joined: Wed Sep 30, 2020 9:53 pm

Re: Delocalized Pi Bond

Postby Lilly Catarozoli 1B » Sat Nov 28, 2020 3:57 pm

I think delocalized correlates to if the structure has resonance or not. If it has resonance, then the electrons would be delocalized because they don't have one singular place.

Mackenzie Stockton 2H
Posts: 97
Joined: Wed Sep 30, 2020 10:11 pm

Re: Delocalized Pi Bond

Postby Mackenzie Stockton 2H » Sat Nov 28, 2020 4:00 pm

delocalized pi bonds occur when the molecule with the pi bond has resonance. Remember that resonance structures have atoms that all have the same bond lengths. For a resonance structure with double and single bonds, the actual bond length is in between double and single. Because all bond lengths have some double bond character, all bonds are delocalized pi bonds, in which the electrons are not localized/confined to a specific region of the molecule and are therefore free to move around.


Return to “Determining Molecular Shape (VSEPR)”

Who is online

Users browsing this forum: No registered users and 3 guests