A conjugated ring of unsaturated bonds, lone pairs, or empty orbitals which exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. This tag should also be applied to antiaromatic compounds. This tag should not be applied to general questions about ...

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How to determine ortho/para substituents on the aromatic ring via NMR ?

I have no idea how to determine the substituents on the aromatic ring from NMR diagram. There is (might be ) a triplet on my NMR around 7.59-7.65ppm which has 4 hydrogens in the same environment. If ...
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62 views

NMR: Magnetic and chemical equivalence in benzene

According to my textbook, all the protons in $\ce{^{12}C_6{}^{1}H_6}$ are magnetically equivalent, but those in $\ce{^{13}C_6{}^{1}H_6}$ are not. I understand that for two nuclei to be magnetically ...
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66 views

Resonance of Aromatic compounds

I have a confusion... Do compounds like tropolone, furan and thiophene which are aromatic show resonance? If yes then what are the resonating structures ? Also do all aromatic compounds show ...
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41 views

What is the reasoning behind the resonating structure of halo-benzene? [closed]

Can anyone explain the resonating structure of halo-benzene? How does the transfer of an electron from the halogen atom to the α-carbon and from there to ß-carbon and so on take place?
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1answer
35 views

Why aryl halides are very less reactive towards nucleophilic substitution reactions? [duplicate]

I've often herd that aryl halides are very less reactive towards nucleophilic substitution reactions. One of the reasons for this I found was that there is resonance effect in the compound, but how is ...
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38 views

When does nitrogen contribute its electrons to aromaticity?

I've been told that this molecule is aromatic. As it has four obvious pi electrons (in the double bonds), I assumed that it was anti-aromatic as opposed to aromatic. I've been operating under the ...
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81 views

Electrophilic substitution of pyrrole (regioselectivity)

Why when pyrrole participates in an EAS, the alpha position is so much preferred over the beta position?
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1answer
58 views

Why isn't this a compound?

I don't know what to call it I'll just provide a link. From what I can tell it is impossible, but why? http://www.chemicalize.org/structure/#!mol=structureId%3A1609384473364&source=calculate
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1answer
86 views

Why is a hydroxyl group more activating than a methoxy group in electrophilic aromatic substitution?

Why is phenol more reactive towards electrophilic substitution than methoxybenzene? Isn't the lone pair on the methoxy group oxygen more available for participating in resonance into the ring than the ...
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1answer
39 views

Why do the two methylene protons in ethylbenzene have a chemical shift at 2-2.9?

The data sheet does not have any chemical shifts in this range for compounds containing only carbon and hydrogen
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26 views

Aromatic ring substitution: how are MNT and DNT further nitrated if nitro groups deactivate benzene rings?

This is probably a common question because it involves TNT precursors, but if an $\ce{NO2}$ group deactivates benzene rings toward electrophilic aromatic substitution reactions, then how can toluene ...
2
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1answer
40 views

Friedel-Crafts synthesis - How is HCl produced?

In the mechanism for the acetylation of bromobenzene, how is $\ce{HCl}$ gas produced? The reactants are acetic anhydride, bromobenzene, $\ce{AlCl3}$ and dichloromethane. Initially, ...
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99 views

Acetylation reaction

In the Friedel - Crafts acetylation of bromobenzene, how is it possible to obtain a black-coloured product? When the acetic anhydride was slowly added to the reactants - $\ce{AlCl3}$, DCM, ...
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2answers
124 views

Resonance structure of cyclobutadiene?

I studied cyclobutadiene as an anti-aromatic compound. But I am unable to draw the resonance structures for cyclobutadiene. Can anyone help me? What is the driving force for the resonance to start? ...
4
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2answers
63 views

What is the resonance structure of nitro-aminobenzene with a broken aromaticity?

According to my course of organic chemistry, nitro-aminobenzene has to break his aromaticity to delocalize the electrons of the amino-group in the nitro-group. I don't really see this, when I draw the ...
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1answer
51 views

Electrophilic aromatic substitution with fluorine

Why don't we usually use diatomic fluorine in electrophilic aromatic substitution? Is it because fluorine is a potent oxidizer and will react with the carbons? What might happen if we reacted ...
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2answers
195 views

why is benzoic acid stronger acid than 3-aminobenzoic acid?

why is m-aminobenzoic acid weaker acid than benzoic acid? obviously at m-position only -I effect will be shown but how doeas that make it a weaker acid than benzoic acid??
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1answer
285 views

Is the Nitrogen in pyridine electron withdrawing and what effect does this have on electrophilic substitution?

If I were to attempt to nitrate Pyridine (essentially benzene but with one carbon replaced with Nitrogen) would I get substitution at the Ortho-, Meta- or para position? Also why is this? I can only ...
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2answers
71 views

Extended conjugation in cyclic ketone

This is a continuation of Aromaticity of cyclic ketone So, I'm looking at the molecule that does have the carbonyl double-bond. Is this resonance structure considered aromatic? Would the electrons ...
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3answers
245 views

How are Phenols made?

What are the equation and condition for the synthesis of Phenols? Would it work if we added NaOH to Benzene and then reflux?
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2answers
163 views

Role of Alcohols(EtOH,MeOH) in nitro reduction used for Metal(Sn,Fe)

Hi. I'm trying to nitro benzene reduction. I understand these reactions are radical reaction by metal, but i don't understand why use alcohols as a solvent. Alcohols are role of proton source? or ...
4
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1answer
312 views

Structure of carbon fiber

What is the structure of carbon fiber? Wikipedia doesn't give much insight. The atomic structure of carbon fiber is similar to that of graphite, consisting of sheets of carbon atoms (graphene ...
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1answer
161 views

Difference between any arene and an aromatic compound?

I can't seem to find what the difference between these two is. In my text book, it says that 'arenes are aromatic hydrocarbons containing one or more benzene rings' which to me suggests that arenes ...
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1answer
73 views

Abstraction of a proton in cycloheptatriene

So, whenever there is abstraction of H+ by an acid-base reaction, I see that the proton on the sp3-hybridized carbon is taken. Why is this if you take into account that vinylic hydrogens are more ...
4
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1answer
317 views

Is the Kekule structure of benzene completely wrong?

I've found out about something called resonance but I'm getting the impression that this indicates the kekule structure is possibly correct as it uses double bonds (I thought that the delocalised ...
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1answer
37 views

Effect of temperature on benzenediazonium

What will benezendiazonium ion become if it is not maintained at temperature below 5 degree celsius during diazotization?
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1answer
58 views

Effects Guiding Electrophilic Aromatic Substitution

This is a question which I come across in an examination. I know the answer and also know the solution. Well when I first saw this problem I didn't know how to approach this problem and I think I ...
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477 views

How does a Frost diagram reproduce the solutions to the wave equation?

I came across a Frost diagram for cyclic compounds in my book, and all my book had to offer was that it geometrically reproduces the solutions of the wave equation, and can therefore determine the ...
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3answers
672 views

Is aniline aromatic - How to treat the lone-pair electrons of nitrogen when applying Huckel's rule?

Why is aniline aromatic? Doesn't it have 8 pi electrons, thereby violating Huckel's rule? The way I see it, there are 6 pi electrons from the benzene ring, and an additional 2 from the sp2 ...
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2answers
99 views

Formation of 2,4-Dichlorophenol by free chlorine mediated oxidation of Triclosan

I cannot find much guidance in the literature. This is the reaction between free chlorine in water and triclosan. I understand ether cleavage and electrophilic aromatic substitution (maybe) involved. ...
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1answer
570 views

Regioselectivity of Birch reduction (electron donating groups)

Why does Birch reduction on benzene derivatives with an electron donating group happen at ortho and meta positions? When the substitute is electron withdrawing, ipso and para reduction take place ...
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1answer
85 views

Are phenylboranes susceptible to ipso or meta substitution?

Are phenylboranes susceptible to ipso or meta electrophilic aromatic substitution, i.e. what's the regioselectivity?
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110 views

Donation by inductive effect and withdrawal by conjugation

Is there a group that would attached to a benzene ring, donate electrons by inductive effect and withdraw them by conjugation?
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137 views

Nitrosation of benzene

How does benzene react with $\ce{NaNO2/HCl}$? Will $\ce{PhNO}$ be obtained? I read that pyridine can be produced under special conditions, but what will happen in some less exotic conditions?
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242 views

Are there any negatively charged electrophiles, or simply neutral and positive?

When reading up on electrophilic aromatic substitution, most resources refer to electrophiles as positively-charged species, "in general" or "mostly". What are non-positively charged electrophiles? ...
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1answer
61 views

Is it possible to make meta-phenol?

Normally phenols have the $\ce{OH}$ group at the 1 or 4 position. Can they be made at 2 or 3 positions, where nitro groups and $\ce{-CN}$ can attach? If not, why not?
2
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1answer
188 views

Aromaticity of cyclic ketone

By looking at the structure of the uploaded ketone, it doesn't seem that it is aromatic, but the resonance structure with C(+)-O(-) is aromatic. Is it correct to say that the ketone in the image is ...
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1answer
59 views

Converting cyclic compounds to linear compounds (possible ?)

Can one convert from cyclic convert to linear compound? Like $Cyclohexane$ $+$ $?=Hexane$ Even in High Temp and Pressure? I know it is very tough since we are going from a stable compound to a ...
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What sort of lab can determine PAH concentration in a soil or charcoal sample? How difficult is it to do?

Non-chemist here. I'm curious how difficult it is to determine concentration of PAH in a sample of soil or powdered charcoal, or a sample of the two mixed together. What would be involved in doing ...
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2answers
190 views

Why does m-cresol exist, given that -OH group is activating and should be o-, p-directing?

Why does m-cresol exist? The $\ce{-OH}$ group is a ring activating group, and hence should be o-, p- directing.
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Why does fusing benzene rings not produce polycyclic alkynes?

It would make sense that when the benzene rings are fused they keep their pi bonds and form a polycyclic alkyne. However this is not the case. My hypothesis is that because monocyclic alkynes at 8C ...
3
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1answer
104 views

What's the difference between Carvacrol and Thymol?

What is the difference when it comes to separating Carvacrol and Thymol on HPPLC with reverse phase - C18 column? Carvacrol elutes first, is that because it is ortho?
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Hydrogen suspended in the center of an aromatic ring and NMR

My textbook (Organic Chemistry, 2nd Ed. Hornback, Joseph) states that if a hydrogen is located near the center of an aromatic ring it will experience an (often quite sizable) upfield shift, as seen in ...
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2answers
295 views

Preparation of phenylamine/aniline

This is the procedure I carried out in class: Reduction of nitrobenzene by using tin and $HCl$ acid After the completion of the reaction, $NaOH$ added to neutralize excess acid and dissolve any ...
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1answer
122 views

Draw pyridine as an R Group

You know how when you carry out a reaction with many compounds, when drawing the reactions you just draw a line at a right angle to the bond with a 'R' at the end (see image)? Then you can specify ...
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3answers
873 views

what is the origin of the colour of azo dyes?

what is the origin of the colour of azo-dyes? Is it the same reason as to why transition metal complexes have colour?
5
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1answer
113 views

Steam distillation- how it actually works?

To obtain phenylamine after it is formed from the reduction of nitrobenzene with tin, we carried out steam distillation. This is what I learned in class: "During the process,steam is injected ...
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2answers
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reason for the stronger acidic property of phenol than alcohol

"In phenol, pulling the $p_z$ electrons from the oxygen atom into the ring causes the hydrogen atom to be more partially positive than it is in aliphatic alcohols. This means it is much more easily ...
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Does benzene have isomers and resonance structures?

Does benzene have both isomers and resonance structures? I know that it has resonance structures because you can manipulate the position of the double bonds but what about isomers?
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Reasons for dry conditions in substituition reactions with benzene

All substitution reactions of benzene must be carried out in dry conditions with a catalyst that produces a powerful electrophile. This was a statement from my book. My question is, why must it ...