Question about Resonance.....

[rak173]

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In the link above, aren't the first 2 structures exactly same? Like if you flip the first structure around, it would become the 2nd structure. I thought you won't count them (the first 2 structures) as resonance as they are the same exact structure. Am I missing something here? Thanks.

 

[dentalstudent2021]

I believe you are confusing structural isomers with resonance structures. resonance structures are a combination of the same structure where electrons are delocalized.

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https://socratic.org/questions/how-do-resonances-and-isomers-differ
https://answers.yahoo.com/question/index?qid=20090822143038AAWg9pV

 

[rdub]

I see what you are saying...but drawing both of them indicates that the electrons are shared between all three oxygens. Even though it looks like the same structure, I think the important thing is to realize that the electron density is spread out between all of them. If only two of them were drawn, it might be misleading as to how stable they actually are due to multiple resonance forms.

 

[rak173]

I believe you are confusing structural isomers with resonance structures. resonance structures are a combination of the same structure where electrons are delocalized.

.
https://socratic.org/questions/how-do-resonances-and-isomers-differ
https://answers.yahoo.com/question/index?qid=20090822143038AAWg9pV

So resonance structure can be the same structures?

 

[rdub]

Look at the resonance forms for benzene. Its obviously the same structure when you rotate it, but it is still a resonance form because it shows the delocalization of electrons on every carbon in the ring.

 

[DAT Destroyer]

http://www.coursesaver.com/images/quizzes/questions/437/f4b69e5b9354b55834f8c3c5389385e0.jpg

In the link above, aren't the first 2 structures exactly same? Like if you flip the first structure around, it would become the 2nd structure. I thought you won't count them (the first 2 structures) as resonance as they are the same exact structure. Am I missing something here? Thanks.

My professor was nominated for the 1969 Nobel Prize in Theoretical Organic Chemistry......I think he said it best and I will share it with you, as I do my students. Resonance is describing the indescribable in terms of the describable . They do INDEED look the same. I agree 100% with you . HOWEVER.......Let us assume you are correct. This will mean that two different bond lengths appear for benzene...one single, and one double. Thus 2 different bond lengths would be experimentally obtained. This turns out NOT to be seen. Our experiments show only a SINGLE bond length !!! Thus....we need a theory to explain this. Organic chemists use the idea of resonance. The actual molecule is a HYBRID of both forms that you see. Like a child.....you are an individual, but are made up of both your mom and your dad. When looking at resonance forms....do not rotate any structures, because you miss the point and come to the wrong conclusion. Resonance is just a way to represent a structure that cannot be truly identified.

Hope this helps.

Dr. Romano

 

[Torst1996]

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[Dentalco2020]

I think, the last explanation was very clear. I don't understand chemistry well, it's rather hard for me and I always need chemistry assignment help from DoAHomework service. If every teacher could explain simply, it would be wonderful!

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