Linked Questions

3
votes
1answer
2k views

Are resonating structures real or not? [duplicate]

We say that hybrid structure is real. It has distinct properties as compared to its Resonating Structure. Is it because that all the experiments we carry out are on a sample, lots of molecules are ...
3
votes
1answer
707 views

Resonance in ozone and benzene [duplicate]

In inorganic chemistry, I learnt that stability of some atoms like ozone cannot be explained by one structure alone and hence the hybrid of possible structures is taken and assumed to be the structure ...
10
votes
4answers
1k views

Does benzene structure stand for a single resonance form or the whole molecule?

It is known that benzene has two main resonance forms Often we still draw benzene molecule as one of them My question is, actually when we draw the lower figure, do we refer to the whole benzene ...
22
votes
3answers
666 views

What is the isomer distribution in monosubstituted fluorobullvalene?

Bullvalene (tricyclo[3.3.2.02,8]deca-3,6,9-triene) is a fluxional molecule able to interconvert any two carbon atoms through a series of degenerate Cope rearrangements (for more information, see the ...
13
votes
6answers
48k views

How to determine the least stable resonance structures out of a given set?

So I was "happily" doing organic chemistry homework when I came across this question: For 1-methoxy-1,3-butadiene, which of the following resonating structure is the least stable? $$\begin{...
16
votes
2answers
595 views

What are the important implications to the field of chemistry, if any, of the recently confirmed hexavalent carbon species?

I’m struggling to understanding the true nature and implications of recent confirmations of the existence of stable species containing carbon atoms bound six (in another case 5) other carbon atoms. Is ...
8
votes
3answers
3k views

Rearrangement of double bonds

Consider: I found these rearrangements, but I could not understand what the mechanism is behind this. When I searched on the Internet I found the Wikipedia page Di-pi-methane rearrangement.
6
votes
1answer
15k views

Structures for NO+ (Nitrosonium)

There are two possible structures for Nitrosonium : In the first structure, there is a +1 Formal charge on Oxygen, whereas, In the second structure, there is a +1 Formal charge on Nitrogen. Q. ...
5
votes
2answers
6k views

What is the most “important” resonance structure of SCN⁻?

Numerous online references say that $\ce{SCN-}$ has two resonance structures: I am wondering why this structure is not also possible? I expect structure 3 to be rare because of the high formal ...
7
votes
2answers
4k views

What is the “resonance hybrid” of benzene?

In my book, to explain the structure of benzene, it referred to the idea of resonance: The idea of resonance is that the actual molecule is a definite structure that is a hybrid of two or more ...
8
votes
2answers
673 views

Trying to understand the statement: 'Resonance is not a flickering between the contributing states. '

So, the famous resonance definition: it is the weighted average of different Lewis structures.... Well, this is purely wrong. Resonance is nothing but quantum 'superposition of the wavefunctions ...
6
votes
1answer
6k views

What is the order of stability of the resonance structures of furan?

I want to know which are the most stable furan resonance structures. I know that structure number 1 is the most stable, but which one comes after?
7
votes
3answers
4k views

Why does HNO2 not have resonance?

A question on the 1996 AP Chemistry Free Response asks: The $\ce{N-O}$ bonds in the $\ce{NO2-}$ ion are equal in length, whereas they are unequal in $\ce{HNO2}$. Explain. Since the nitrogen ...
2
votes
2answers
811 views

Stability and resonance structures

In school they ask us to count the number of resonance structures in different organic compounds to determine it's stability. The one with more resonance structures is more stable. Is this notion ...
3
votes
1answer
3k views

How to explain (non-/anti-) aromaticity in fulvene with the help of resonance structures?

Can someone please explain why the resonance structures of fulvene 1 is non-aromatic and 2 is anti-aromatic? Why is fulvene non-aromatic, even though it has $4\pi$-electrons and no $\mathrm{sp^3}$ ...
5
votes
1answer
741 views

Where do the lone pairs go in the “true” resonance structure?

Consider the "true" resonance structure of $\ce{CO3^2-}$: The bottom diagram leaves out the 2 lone pairs, so 4 electrons disappeared in the bottom image as compared to the top one. Are these ...
4
votes
1answer
684 views

VSEPR theory, chemical bond and quantum mechanics

VSEPR theory correctly predicts the shapes of many symmetry-broken molecules such as $\ce{H2O}$ and $\ce{NH3}$. Take $\ce{NH3}$ for example. In VSEPR theory, the nitrogen atom is (approximately) at ...
5
votes
2answers
354 views

What is the correct way to verify a structure's geometry, for example for benzene?

My goal is to compare a calculated bond length with experimental data. Benzene is obviously common enough to expect sufficient experimental data to be available for it on the internet. I have found ...
6
votes
1answer
236 views

If I can't draw resonance structures for a pi system, does that mean it doesn't exist?

Whilst trying to answer this question I came across an interesting situation regarding the relationship between resonance structures and molecular orbitals. There are two places that you can ...
3
votes
1answer
69 views

How does resonance fail in approximating chemical structures?

In the book "Concise Inorganic Chemistry" by Prof. JD Lee, it says here: These contributing structures do not actually exist. The $\ce{CO3^2-}$ does not consist of a mixture of these structures, ...
4
votes
1answer
145 views

Can a molecule be achiral whilst it's resonance form chiral?

I'm trying to work out whether methylphenylsulfoxide is a chiral molecule. It is my understanding that the sulfur uses sp2 hybridised orbitals. Why is this? The central sulfur atom is bound to 3 ...
0
votes
1answer
192 views

Generalizations regarding functional groups on benzene ring

While studying several organic mechanisms (high school level), I came to an interesting generalization. I claim that negative charge on phenoxide ion first ALWAYS delocalises onto the ring and then ...
1
vote
1answer
76 views

Why does coumarin predominantly exist in keto form?

By applying the logic that phenol exists in enol form rather than keto form as it attains aromatic character, why is it not the case in coumarin?
0
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0answers
219 views

Which is most stable resonance structure of 4-nitrophenoxide ion?

According to my coaching module the first structure is more stable. Why is this so? I feel both must be approximately equally stable since negative charge is on oxygen in both cases. Would someone ...
-1
votes
1answer
144 views

Resonance structure and stability

Does the existence of resonance structures always translate as stability? I've been taught that resonance structures generally "spread out" charge in order to compensate for deficiency or excess of ...
2
votes
0answers
121 views

Mechanism of Biosynthesis of Terpenes

There is a specific part of the biosynthesis of terpenes that makes me confused: According to this mechanism, the double bond of the isopentenyl pyrophosphate attacks the primary carbocation, when it ...
1
vote
1answer
101 views

Which of the resonance structures is more stable?

I am quoting a rule on resonance from Organic Chemistry by T.W. Graham Solomons, Craig B. Fryhle, 12th edition, page 25. Structures in which all the atoms have a complete valence shell of ...
0
votes
0answers
32 views

Stability and Resonance [duplicate]

The linked answers do attempt to clarify on 'stability' but I wanted an answer with specific connection to resonance. For example, the ethanoate ion can exist in many forms but, as we know from data,...
0
votes
0answers
26 views

Resonance structures and mechanism

I wrote the following resonance structures and our teacher wants us to write the curved arrows showing the mechanism as well... I was wondering if it's okay to show in which direction the mechanism ...