Resonance Structures for a Certain Molecule

[alingy1]

Please look at the pictures.

I do not understand why they have not included the resonance structure for that molecule for which all the double bonds are displaced is not included.

 

[Yanick]

Your structure in red is the first structure they drew. Are you referring to some other resonance structure?

 

[alingy1]

http://www.chem.ucla.edu/harding/tutorials/resonance/draw_res_str_key.html

The position of atoms should not change and all possibilities of electrons moving should be shown. This website seems to agree with me.

 

[Yanick]

I don't see any atoms changing in the first picture you uploaded, but I could be tired (or stupid). Are you perhaps referring to the pi electrons shifting within the ring? Technically they have shown ALL possible resonance structures with the dashed lines and partial charges in the first picture. If I am misinterpreting, please post a picture of what you believe the missing resonance structure is.

EDIT: I've looked closer at your first two pictures and now I see what you mean. Yes you are kind of correct, but so is the first picture due to inclusion of the bottom structure with the dashes (see my comments above).

 

[DeeNos]

I would like to clarify that resonance structures are not definitive representations of a molecule's structure, but rather a way to illustrate the delocalization of electrons within a molecule. Therefore, it is possible that some resonance structures may not be included in a particular depiction, as they may not contribute significantly to the overall electronic structure of the molecule. It is also important to note that resonance structures are not separate molecules, but rather different representations of the same molecule.