Questions tagged [halogenation]
For reactions involving the formation of a C-X bond.
37
questions
1
vote
1answer
32 views
Is the polarisation of halogens of higher atomic number easier because the electrons are further away from its core?
This question concerns the dihalo addition reactions. I've learned that a halogen molecule (which, of course, consists of two atoms of the respective halogen) is more easily polarised by the double ...
0
votes
0answers
39 views
Exception to haloform reaction
While explaining haloform reaction my teacher told me that Me3C-(C=O)-CH3 does not give haloform reaction.
What is the reason behind it since it does have a CH3 group?
0
votes
0answers
21 views
Halogenation by Phosphorous tribromide vs using HBr
My textbook introduced PBr3 by stating that it leads to an inversion in stereochemistry since it always goes through an SN2 pathway, unlike using HBr.
My question is that since Br- is a reasonably ...
-1
votes
1answer
35 views
Halogens chemical reactions with each other [closed]
https://en.wikipedia.org/wiki/Halogen
Can Halogens react with each other?
Examples :
Chlorine + Flourine
Flourine + Iodine
Iodine + Bromine
Chlorine + Bromine
and so on.
Permutations and Combinations.
...
1
vote
0answers
34 views
What makes a good chlorinating agent?
From what I know, good inorganic chlorinating agents, $\ce{SOCl2, PCl3, PCl5}$ are able to substitute a poorer leaving group (like $\ce{OH-}$) for chlorine. For example, for substitution of the ...
4
votes
1answer
213 views
Safest way to conduct a reaction with bromine under reflux conditions
I am conducting an electrophilic aromatic bromination reaction according to literature. The substrate and intended substitution pattern do not matter, but the reported procedure requires the dropwise ...
1
vote
1answer
188 views
sp2 hybridisation of alkyl radicals causing formation of racemic mixture
What I know about $\ce{^{.}CR3}$ radical is that it has both $\ce{sp^2}$ and $\ce{sp^3}$ character but the $\ce{sp^2}$ character dominates and so the radical is $\ce{sp^2}$ in nature.
So, suppose we ...
1
vote
0answers
45 views
Problem encountered during high school unsaturated fats experiment
To get straight to the point, my chemistry experiment was looking at the amount of unsaturated fats in avocado oil with respect to temperature. I did this by testing for the $\ce{C=O}$ bonds using ...
2
votes
0answers
81 views
why the terminal Br/Cl is an electrophile in AlBr5/AlCl5 complex? [closed]
In halogenation of benzene, e.g. bromination, $\ce{AlBr3}$ and $\ce{Br2}$ is added in order to make $\ce{Br+}$ by forming delivery agent $\ce{AlBr5}$ (step 2 of picture).
Why is the terminal (...
3
votes
1answer
154 views
Total number of isomers formed on monobromination of 2-methylbutane
What is the total number of isomers formed on monobromination of 2-methylbutane (including configurational and stereoisomers)?
I tried working it out. However, I found only five:
According to the ...
1
vote
1answer
77 views
Why 4‐methylidenespiro[2.4]heptane cannot be converted to 1‐chlorobicyclo[3.2.0]heptane? [closed]
According to the solution, the following reaction is not correct:
But why? I have tried solving in the following steps:
Forming a carbocation by breaking the double bond.
Expanding the ring.
...
1
vote
1answer
81 views
Where will halogenation take place?
In the following halogenation reaction:
At which position will halogenation take place?
It is obvious that the halogenation will take place at a 3° Carbon atom (the rates of halogenation for ...
0
votes
1answer
95 views
Reaction Mechanisms: Free Radical Halogenation
In Free Radical halogenation using chlorine and sunlight, why does the chlorine-free radical get attached to the allylic carbon?
Will it be correct to say that it follows the anti-Markovnikov rule?
...
-2
votes
1answer
52 views
Can iodine replace other halogen as well?
While reading about halogen family I encountered the reaction:
$$\ce{NaClO3 + I2 -> NaIO3 + Cl2}$$
I know that that the oxidizing tendency of halogens decreases down the group, so I think that the ...
1
vote
2answers
190 views
In free radical substitution of propane with halogens, how do you know which carbon ends up with an unpaired electron after fission of C-H bond? [duplicate]
In free radical substitution of propane with a halogen (eg- chlorine), how do you know which carbon out of the three ends up with an unpaired electron after fission of C-H bond?
This image shows ...
-1
votes
2answers
71 views
Does halogen addition occur without sunlight [closed]
Can this reaction occur;
(2-Bromopentane) + Br2 --(300°C)--> (2,3-Dibromopentane)
As far as I know, halogenation can only occur in UV or sunlight, not with just a high temperature. So how does this ...
2
votes
1answer
81 views
Reaction of octahydroazecine with iodine crystals [closed]
I really don’t understand why the following reaction would take place first of all.
So this is a sub part of a question wherein we have to compare the basicity of the compounds formed through some ...
3
votes
2answers
157 views
Deriving rate law from a reaction mechanism for a chain reaction using steady-state approximation
I am trying to derive the overall rate equation for the photocatalysed halogenation (chlorination) of an alkane that proceed via this 4 step chain reaction:
$\ce{Cl2->2Cl^. \quad(1) initiation}$
$\...
4
votes
2answers
86 views
Halogenation of 4‐methylcyclohex‐1‐ene
My problem is with the methyl group. If it wasn't there, I had no problem.
When the halonium bridge is made does the methyl group shift to give a more stable transition state or not?
-2
votes
1answer
413 views
What is the mechanism for trans-stilbene to stilbene dibromide?
What is the mechanism for trans-stilbene to stilbene dibromide?
This is what I know:
The bond between the hydrogen and bromine is broken and the bromine is given a negative charge, while the $\ce{H}$...
-1
votes
1answer
597 views
Can sulfuric acid attack a hydrocarbon/paraffin? Under what conditions? [closed]
Sulfuric acid can attack benzene and other hydrocarbons (when mixed with hydrogen peroxide). Also, chlorine gas and bromine can replace hydrogen(s) in hydrocarbons like methane, ethane, propane,butane ...
0
votes
1answer
252 views
Bromination of an alkene in presence of water
Bromination of an alkene in presence of water results in its mechanism in a cyclic bromonium ion and "afterwards $\ce{H2O}$ binds to the carbon atom surrounded by more electron donating groups."
This ...
1
vote
0answers
30 views
Will a Lewis acid catalyze the reaction of HBr with primary alcohols?
It is well-established that a Lewis acid catalyst (popularly $\ce{ZnCl2})$ is necessary to form an alkyl chloride when reacting $\ce{HCl}$ with a primary alcohol. This actually changes the mechanism: ...
0
votes
1answer
212 views
Mechanism of 5‐(iodomethyl)oxolan‐2‐one synthesis from 4‐pentenoic acid and iodine in acetonitrile [closed]
There is a question in my organic chemistry textbook with an answer. What it doesn't explain (and neither does my theory textbook, I checked) is the mechanism involved in the reaction. The reaction is ...
0
votes
1answer
773 views
How many products does this reaction yield?
How many products can we get from the monochlorination of 2,4-dimethylpentane including stereoisomerism? I have seen someone say that it yields 3 structural isomers one of which has two enantiomers ...
2
votes
1answer
633 views
Di-alpha-halogenation of ketones in acidic medium
I was studying alpha-halogenation of ketones from LibreTexts Chemistry,
Under acidic conditions the reaction occurs through the formation of an enol which then reacts with the halogen${^1}$.
1) ...
1
vote
0answers
242 views
Does acetophenone show haloform reaction?
Although acetophenone is a methyl ketone, as it is aromatic, it is immiscible in H2O so the last step in the haloform reaction should not occur?
I couldn't find any source regarding the haloform ...
0
votes
1answer
3k views
What happens when HCl is added to acetylene in presence of mercuric ions?
Normal addition of Hydrochloric Acid to acetylene would give me a 1,1 Dichloro product.
But I read that in presence of mercuric ions only one molecule of HCl is added to give Vinyl Chloride.
Why does ...
1
vote
1answer
418 views
Reaction between phenylamine and halogens
I understand that phenylamine is considerably more reactive than benzene, meaning that it is able to react with bromine water to give 2,3,6-tribromophenylamine. But I was then wondering why I haven't ...
3
votes
3answers
2k views
Mechanism with hypohalite in haloform reaction
The haloform reaction is usually done in a solution of NaOH and $\ce{I2}$ (or indeed, any halogen). Now the first part of the reaction mechanism in the wikipedia page and in the most organic books ...
4
votes
2answers
115 views
Finding major product when bromonium compound is acted upon by a nucleophile
The original question is:-
The major product obtained in the following conversion is:-
(Note that Me here means methyl group)
The initial step would be the formation of a bromonium ...
1
vote
1answer
2k views
Which will be the major monochlorination product? [closed]
Which of these compounds represents the major monochlorination isomer formed in the following reaction?
According to selectivity theory, the answer should be (c). However, the given answer is (b).
4
votes
1answer
5k views
What is the rate-determining step in free radical halogenation?
Recently, we were learning about free radical halogenation in school. A set of notes given to us wrote that the rate-determining step is the propagation step. This seems to go against my understanding ...
2
votes
1answer
527 views
Bromination with NBS on cyclic structures
I found this question and the answer as shown in my book. I didn't understand why the bromine particularly entered the position shown in the answer.
First of all, if a free radical was generated ...
7
votes
1answer
2k views
Why is free radical chlorination exothermic whereas bromination is endothermic?
In the energy profile diagrams below, it can be clearly seen that the free radical chlorination of an alkane
$$\ce{RH + Cl2 -> RCl + HCl}$$
is exothermic. However, the corresponding bromination
$...
4
votes
1answer
247 views
Does the Lewis acid have to match the halogen in electrophilic halogenation of benzene
$\ce{FeBr3}$ catalyzes bromination and $\ce{AlCl3}$ chlorination. I'd like to know whether bromination and chlorination can be done in sequence without changing the catalyst? So - will using the $\ce{...
5
votes
1answer
3k views
Products of radical bromination and mechanism
My organic chemistry final is next Tuesday, and I have worked through the practice final. The last question is the following: Give and name all the compounds resulting from the radical monobromination ...
