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Topic: Resonance structure  (Read 6073 times)

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Offline sun725

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Resonance structure
« on: December 15, 2016, 01:58:54 PM »
I want to draw the resonance structure of the following drug
https://pubchem.ncbi.nlm.nih.gov/image/imgsrv.fcgi?cid=33741&t=l

I only came up with one resonance structure that it's able to make at the ether group. Is that correct, or is it possible to make more? And what's the importance of this resonance for the electron configuration? I think that it increases the stability by increasing the bonding between adjacent atoms. However, I have a hard time relating it to this example...

Thanks in advance.

Offline AWK

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Re: Resonance structure
« Reply #1 on: December 15, 2016, 02:34:33 PM »
Let's try.
Could you draw resonance structures for phenol or anisol?
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Offline sun725

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Re: Resonance structure
« Reply #2 on: December 15, 2016, 04:30:55 PM »
Okay, I tried with Phenol. Excuse my bad handwriting...
http://imgur.com/a/hpDbh

Offline AWK

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Re: Resonance structure
« Reply #3 on: December 15, 2016, 04:43:23 PM »
In resonance structure you cannot move or remove any atom. You can move only electron pairs (or single electron in the case of radicals). You lost 1 hydrogen atom.
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Offline sun725

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Re: Resonance structure
« Reply #4 on: December 15, 2016, 04:52:20 PM »
Yes, I see that now ...
I'll try to show you what I came up with the other molecule that I posted earlier. However, I only drew 1 structure ...

Offline sun725

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Re: Resonance structure
« Reply #5 on: December 15, 2016, 05:30:15 PM »

Offline Babcock_Hall

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Re: Resonance structure
« Reply #6 on: December 15, 2016, 05:33:20 PM »
In general the combination of resonance structures gives a better picture of where the electron density is than any single structure that we could draw.  I would not say that it necessarily increases the number of bonds between two atoms.  However for any particular example, the number of bonds between two atoms is usually different from one resonance structure to the next.

Offline AWK

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Re: Resonance structure
« Reply #7 on: December 15, 2016, 06:11:20 PM »
Oxygen atom in phenol or phenyl methyl ether in mesomeric structures cannot bear negative charge. It is against Lewis theory.
« Last Edit: December 15, 2016, 06:49:04 PM by AWK »
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Offline sun725

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Re: Resonance structure
« Reply #8 on: December 16, 2016, 11:06:02 AM »
Yes, I made that mistake. Tried to correct it and came up with something hopefully a little more correct??

Offline sun725

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Re: Resonance structure
« Reply #9 on: December 16, 2016, 11:08:13 AM »

Offline AWK

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Re: Resonance structure
« Reply #10 on: December 16, 2016, 03:37:58 PM »
One more resonance structure is needed. Then relocate these findings to your structure.
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Offline sun725

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Re: Resonance structure
« Reply #11 on: December 16, 2016, 07:11:43 PM »
Okay,
http://imgur.com/a/gJ2yu

Hoping I got it somehow right now..


Offline AWK

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Re: Resonance structure
« Reply #12 on: December 17, 2016, 12:53:50 AM »
Are you sure that carbon atom can be pentavalent?
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Offline sun725

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Re: Resonance structure
« Reply #13 on: December 17, 2016, 06:15:05 AM »
Okay, that's a huge mistake. That's not possible ...
Feeling very stupid, but that's what I think it should be now...
http://imgur.com/a/x66f4

Offline AWK

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Re: Resonance structure
« Reply #14 on: December 17, 2016, 08:46:17 AM »
On the last structure + and - are missing. Now find on the molecule of tramadol this part which looks like to anisole and draw resonance structures of this pain medication.
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