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Homework Help: Why is this showing resonance?

  1. Jan 20, 2012 #1
    1. The problem statement, all variables and given/known data
    Why does the following structure show resonance?

    2. Relevant equations

    3. The attempt at a solution
    The question was given by my teacher and he said that yes it will show resonance. But i still can't able to make it out why would it show resonance? The point is Nitrogen is more electronegative than Carbon and therefore should not show resonance but yet it does. It passes one of its electron from the lone pair to the carbon and makes a covalent bond. I don't agree with this because nitrogen is more electronegative and should avoid giving its electron to the carbon.

    Any help is much appreciated.
    Thanks! :smile:
  2. jcsd
  3. Jan 21, 2012 #2
    Can i expect a reply? :uhh:
  4. Jan 21, 2012 #3

    I like Serena

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    Homework Helper

    Hi Pranav-Arora! :smile:

    I just looked up the wikipedia definition of resonance.

    Turns out that if you can form covalent bonds in different ways, the actual molecule is neither, but a hybrid form in between.

    As it is, benzeen (C6H6) has 2 different covalent bond structures as you can see here:
    Resonance structures of benzene

    The same would be true if you replace one of the carbon atoms by a nitrogen atom.
  5. Jan 21, 2012 #4
    *At least somebody cared to reply, thanks! :smile:*

    I already know about the things you just posted and that's not the main problem for me. I asked why the nitrogen atom would ever pass its electron to carbocation even if it is more electronegative. Nitrogen should not give its electron to carbon due to higher electronegativity character.
  6. Jan 21, 2012 #5


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    Staff: Mentor

    The difference is not that high, around 0.5 unit.
  7. Jan 21, 2012 #6

    I like Serena

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    Have you considered that there's just not that many people around PF that know about this stuff? :wink:
    I only know because I looked it up.

    Now if you had some more questions on math or physics...

    Seems to me that nitrogen can form different bonds with the 2 carbon atoms next to it regardless of its electronegativity.
    This would imply a resonance structure.
    (But I'm not a specialist. :shy:)
  8. Jan 21, 2012 #7
    Only 0.5? lol

    What if we replace Nitrogen with Oxygen?

    Don't talk about that stuff, i have already lost interest in it. :smile:
    Last edited: Jan 21, 2012
  9. Jan 21, 2012 #8
    you can make a triple bond on nitrogen making it positive so yes there is resonance.
    EN doesn't stop anything from performing resonance. Except most likely your prof will say not to touch the benzene ring.
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