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 ...

learn more… | top users | synonyms (1)

-1
votes
0answers
13 views

organic chemistry ( relative rates of bromination) [on hold]

4 different aromatic compunds (Acetanilide, Anisole, Phenol,p-Nitro phenol) are reacted with bromine solution (in 90% acetic acid). phenol has the fastest reaction rate and p-nitro has the longest ...
-2
votes
1answer
28 views

Stability between cyclopentdiene compound

What will be the order of stability? According the me it should be : Cyclopentadienyl anion > Cyclopentadiene > Cyclopentadienyl cation because the order of stability is aromatic > non-aromatic ...
0
votes
1answer
23 views

Why does nitration of aromatic amines give meta directed nitro compounds?

Amines are activating groups and donate electrons to the resonance structure using the lone pair of electrons on Nitrogen. But when aromatic amines are nitrated, for example when benzyl amine is ...
3
votes
1answer
44 views

Semi-sandwich complex IUPAC name

I've tried looking here, but I can't figure it out. As a start, what is just the cobalt and cyclopentadienyl anion compound called. How does that name get added to the trimethylphosphine and ...
4
votes
1answer
50 views

What molecule is mostly responsible for the smell of petrol/gasoline when I refill my car?

Is it benzene or is there another aromatic molecule in gasoline with "heavier scents"? Does anybody know of a scientific investigation to provide evidence for an answer?
0
votes
2answers
54 views

Substitution of nitro benzene

In the following reaction why OEt does not get attached to meta of NO2 . As there would be -M of NO2 and -I of Cl. But why it get attached at para of NO2 1: I am thinking of compound as ...
10
votes
1answer
126 views

Does aromaticity require a co-planar pi system?

It's well established that angular twisting can decrease the degree of delocalization across a $\pi$ system (e.g. biphenyl). Moreover, there's considerable debate about aromaticity in spherical ...
8
votes
1answer
573 views

Why is the cyclopropenyl anion “Not Aromatic”?

Is the following compound "Anti Aromatic" or "Not Aromatic" ? The above compound contains a single ring, has conjugation and also has $4 \ (=4n)$ electrons. So, according to Hückel's ...
1
vote
1answer
90 views

What is the IUPAC name of this Di-Benzene like compound? Is it Aromatic?

What is the IUPAC name of this compound? Is it Aromatic? The above compound has $12 \ \pi$ electrons and according to Hückel's Rule, it should not be aromatic because $12 \neq 4n+2$, but it ...
0
votes
0answers
19 views

what is the bond order if chloro benzene?

my teacher taught me to first find the confirming/canonical structures then selecting a pair of atoms connected by a bond and then use the formula Total no of bonds present between the pair in all ...
-1
votes
0answers
18 views

Positions of electrophilic attack for the given reaction

The main positions of electrophilic attack in given reaction...I am fine with discussing about electrophilic attack on single benzene ring with substituents..but how to compare these type of things... ...
3
votes
1answer
75 views

How are the electrons of benzene actually configurated?

I found this diagram here: According to it, it is not true that the six electrons of carbons in the pi-orbitals above the ring are all identical. But, how can it be the case, seeing that this ...
0
votes
0answers
26 views

Will non planar electrophiles attack benzene ring faster than corresponding planar electrophiles of comparable electrophilicity

Will non planar electrophiles attack benzene ring faster than corresponding planar electrophiles of comparable electrophilicity . As we all know know that benzene is a planar molecule with the pi ...
10
votes
1answer
175 views

Mechanism of a dephenylation reaction

I recently came across this reaction in my undergraduate labs. The experiment is taken from this article: J. Chem. Educ., 2008, 85, 413. The condensation of 2-methoxynaphthalene with cinnamoyl ...
3
votes
1answer
78 views

Why are antiaromatic compounds unstable?

Antiaromaticity is so destabilizing that it can cause compounds such as cyclobutadiene to elongate or manipulate their orbitals so that the pi system is no longer aromatic. I understand that aromatic ...
0
votes
0answers
11 views

Friedel craft alkylation of toluene [duplicate]

When toluene is reacted with CH3Cl , AlCl3 with heat . Then the product is m-xylene. But methyl group is o,p-director , so according to me o-xylene and p-xylene must be formed .
1
vote
1answer
50 views

Hybridization of nitrogen in a ring [closed]

Is there a well defined way to discern the hybridization of a nitrogen atom in ring, like pyrrole? How can you know whether the nitrogen's lone pair are in the conjugated system or not?
0
votes
0answers
22 views

Ortho para or meta directing [duplicate]

As we know CH3 is ortho para directing . Then why the following rection gives meta directing .
5
votes
2answers
90 views

Is ciprofloxacin acidic or basic?

I would expect an aqueous solution of ciprofloxacin to be basic for the following reasons: The carboxyl group has pKa = 6.09 and the secondary amino group has pKa = 8.74. Because 8.74 is further ...
19
votes
1answer
774 views

Why is pyrimidine less basic than pyridine?

From Wikipedia's article on pyrimidine: Because of the decreased basicity compared to pyridine, electrophilic substitution of pyrimidine is less facile. But why is pyrimidine less basic than ...
3
votes
1answer
96 views

Why is the lone pair of pyridine's nitrogen atom not part of the aromatic ring?

In pyrrole, the lone pair of electrons belonging to the nitrogen is part of the aromatic ring. However, in pyridine it is part of an sp2-hybridized orbital. Why can't it be in the p-orbital and take ...
0
votes
2answers
103 views

Why can't oxygen in furan be sp-hybridized?

From ChemWiki's article on Huckel's Rule: So far, you have encountered many carbon homocyclic rings, but compounds with elements other than carbon in the ring can also be aromatic, as long as ...
8
votes
1answer
83 views

How much steric hindrance does a phenyl group offer?

I've come across a question in my revision in which I am asked to compare the steric hindrance provided by a number of substituents. Those relating to phenyl are ranked relatively low, despite it ...
1
vote
1answer
94 views

Why are anti aromatic compounds unstable?

Just like aromatic compounds, anti aromatic compounds have several resonance structures and some of them are also conjugated ( 1,3-cyclobutene). Why is it that just having 4n electrons makes them ...
0
votes
0answers
27 views

Resonance in phenoxide anion [duplicate]

Why is resonance possible in phenoxide anion as when the electron pair of oxygen is involved in conjugation we have 4 pairs of electrons in resonance which should imply that the ring has become anti ...
0
votes
0answers
23 views

Mesomeric structures in aromatic compounds

Can electrons be transferred to a neutral atom as in resonance of C6H5OH. here double bond transfers electrons to c of ch and c gets negative charge. while in other compounds of benzene rigs electrons ...
3
votes
1answer
88 views

Friedel-Crafts alkylation of five-membered heterocycles

The five-membered heterocycles pyrrole, furan, and thiophene undergo Friedel-Crafts acylation, but I have not seen them undergoing a simple Friedel-Crafts alkylation reaction with a Lewis acid such as ...
0
votes
1answer
42 views

Basicity of heterocyclic compounds

Pyrrol, furan or thiophene don't have any bond pair electrons free to release which is why they shouldn't be basic, but the lecturer of organic chemistry is saying that they are basic as they react ...
4
votes
1answer
72 views

Synthesis of indigo from anthranilic acid - reaction not taking place

I was trying to synthesise indigo via the Heumann indigo synthesis (II.), which involves heating antrhanilic acid and chloroacetic acid, both dissolved in isopropanol. After heating up, a hydroxide or ...
3
votes
1answer
55 views

Formation of Tropylium carbocation

I've read that Tropylium carbocation is formed by the ring expansion of benzyl carbocation. But in benzyl carbocation, the $\ce{C}$ atoms in the benzene ring are $sp^2$ hybridized i.e. $120^\circ$ is ...
2
votes
2answers
81 views

Most acidic compound amongs the following unsaturated ketones?

In the given picture, I know that the most acidic will be (a), because of potential of ring expansion. I tried a few times but wasn't able to get a satisfactory six membered ring. I think (a) is the ...
3
votes
1answer
85 views

Why does selenophene not undergo aromatic substitution?

Other derivatives like thiophene, pyrrole give electrophilic substitution but why not selenophene? Is it because selenophene does not have enough electron donating effect and not having its electrons ...
12
votes
1answer
183 views

Are graphite and boron nitride aromatic

Are graphite and boron nitride aromatic? Graphite has a planar network of $6$-membered rings with each carbon connected to three other carbons. Since the valency of carbon is not satisfied, there ...
1
vote
0answers
29 views

Determining where a group will direct an addition

I'm looking at a phenol with a ketone in one of the meta positions being treated with $$ \frac{Cl_2}{AlCl_3} $$ I know the Alcohol is the stronger activator because ketone is a deactivator. I'm ...
1
vote
0answers
21 views

Which catalyst should I use? [closed]

What is the catalyst should I use in the reaction of halogenation " electrophilic substitution reaction" of Benzene? Fecl3 or FeBr3 ? And why?
8
votes
2answers
284 views

Comparing the reactivity towards aromatic electrophilic substitution reaction

In the following pairs of molecules, which is more reactive towards electrophilic substitution reaction? 1) 1,4-dinitrobenzene or 1,3-dinitrobenzene (don't consider the ortho isomer) 2) ...
6
votes
1answer
134 views

Why is imidazole considered an electron deficient heterocycle?

The paper I'm looking at mentions electron deficient heterocycles such as (di)azines, benzothiazole and imidazole. Can you tell me the criteria to determine whether a heterocycle is electron ...
4
votes
2answers
78 views

How is it possible that meta xylene exists?

Methyl group is ortho para directing so it should direct the second methyl group to ortho or para position giving rise to ortho or para xylene but how can meta xylene be formed?
0
votes
1answer
55 views

Numbering in chlordiazepoxide

The IUPAC name of chlordiazepoxide is given as : 7-chloro-2-methylamino-5-phenyl-3H-1,4-benzodiazepine-4-oxide, but when I started numbering the structure, I am unable to find chlorine on 7th carbon, ...
5
votes
2answers
141 views

Synthesising Complex Aromatic Compound

I have to synthesis the above compound using only toluene as the carbon source. I have never done something like this before and I have no clue on how to start. I am even more confused by the fact ...
2
votes
1answer
61 views

Simpler synthesis?

I have to obtain 1-nitro-2,4,5-triaminobenzene from 1,3-dichlorobenzene. I have thought of: Reaction with $\ce{Mg}$ Rc with $\ce{CO2}$, then $\ce{H2O}$. By this point I have izophthalic acid. ...
13
votes
1answer
221 views

IUPAC nomenclature for an interesting looking organic compound

How can I name this organic compound while adhering to the IUPAC standards? Excuse me for the terribly hand-drawn hexagons. (Here, the hexagon with the circle in it is essentially a phenyl ...
2
votes
1answer
51 views

Aromatic Apparent Substituion Reaction Mechanism

The first molecule reacts with $\ce{NaOH}$ to form the second molecule. I am told that it does't undergo via a substitution mechanism. I am asked to draw the mechanism for it. I am thinking ...
0
votes
0answers
65 views

Are we wrong about Bakelite formation mechanism?

In the reaction of phenol with acetyl chloride the oxygen of the phenol attacks the acetyl chloride. In Bakelite formation we know that pi electrons attack the carbonyl carbon of formaldehyde.My ...
3
votes
1answer
60 views

O-carboxylation in the Kolbe-Schmitt reaction

In the Kolbe-Schmitt reaction, we know that the pi electrons of the benzene ring attack the carbon in carbon dioxide, but why doesn't the reaction occur on oxygen instead (as shown in the diagram ...
8
votes
1answer
91 views

Bromination of Benzene Based Molecule

Using two equivalents of $\ce{Br2}$ and catalytic $\ce{FeBr3}$ compound A can be converted into B. In the same reaction vessel but in multiple steps the conversion of B into C ($\ce{C11H12Br3I}$) ...
3
votes
1answer
89 views

Zero dipole moment of p-dinitrobenzene

Why is $\mu=0$ for p-dinitrobenzene ? How can the dipole moments of the two Nitro groups exactly cancel each other ? Shouldn't it have a non-zero, albeit feeble, dipole moment ?
3
votes
0answers
72 views

Question about Anti-Aromatic and Non-Aromatic compounds

Why can't just all anti-aromatic systems loose planarity (and hence conjugation) and be non-aromatic like cyclooctatetraene ? ...
1
vote
1answer
57 views

A question about preparation of chlorobenzene

The best method (as I have read) for preparation of chlorobenzene is by reacting it with $\ce{Cl2}$/$\ce{FeCl3}$. Why its not the best practice to react phenol with $\ce{PCl5}$ ?
3
votes
1answer
65 views

How do I convert 4-(Methylthio)benzaldehyde to 4-(thioacetate)benzaldehyde?

Sorry if I have the incorrect name of the final product. I'm trying to acylate the methyl mercaptan substituent to a thioester (thioacetate). I appreciate any help!