Questions tagged [reaction-mechanism]

The detailed (and as complete as possible) description of plausible or observable pathways leading from reactants to products of a chemical process. This tag should be applied to questions about these processes. It may be applied to hypothetical and/or proposed mechanisms.

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Reactions of Grignard Reagents with amides

Can Grignard reagents add to amides? It appears from the synthetic pathway shown below that there has been some form of nucleophilic substitution at the carbonyl group. Source: 49th IChO Preparatory ...
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What can explain the more weight gain of aluminum coated steel than non-coated steel after NaCl immersion?

I have a 2 week experiment. I put aluminum coated and non-coated steel of the same size and shape in separate beakers with NaCl solution. Both are sealed. But, I am surprised that Al coated steel ...
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Reaction of HBr + 2,4-dimethylpent-1,3-diene yields 3 products?

My understanding is that either pi bond can react with HBr but that you still have to follow Marovnikov's rule or whatever. I end up with 2 allylic carbocations that are actually the same molecule ...
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Comparison of ways to provide energy to a reaction

As we all know, you can provide energy to a reaction to overcome the activation energy of a reaction by heating the reaction. I have, however, recently sat through a talk where someone 'powered' a ...
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Abiogenesis: Formation of Lipids from Montmorillonite

I have been really interested in scientific hypotheses regarding abiogenesis, particularly the lipid-world hypothesis. However, I could not find information on the chemical pathway that leads to the ...
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Hoffmann's rearrangement

In Hoffmann's rearrangement of acid amide...the OH from the basic medium attacked the H ..now my question is...isn't the carbonyl carbon more acidic as it's surrounded by 2 electronegative elements?
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Can activated charcoal retain adsorbtion properties even when submerged in liquids?

This is following a question on Skeptics Stackexchange, where apparently medical science claims that activated charcoal can adsorb poison when ingested. One of the members posted a related question on ...
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1answer
983 views

Can the electrophile attack at the position of the NH2 group in nitration of aniline?

In the nitration of aniline, we observe the formation of a meta-substituted product (47%) almost as much as a para (52%). However, can't the electrophile attack at the position where $\ce{-NH2}$ is ...
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221 views

Effect of Temperature on Chemical Reaction Equilibrium

here is the question (part I): For part (i), I need some assistance, I cannot figure out how to do the question. I know eventually what to do, it's just working out the equilibrium constants I'm ...
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Why do fluoride ions “win” over thiocyanate ions in a solution with iron ions?

When you mix aqueous iron(III) nitrate and potassium thiocyanate together you get a red solution. Then if you add sodium fluoride, the red colour disappears. This is basically because the $\ce{Fe(...
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rate constant via flux-flux correlation function for linear potential energy surface

How does one calculate fully quantum mechanical rate ($\kappa$) in the golden-rule approximation for two linear potential energy surfaces? Attempt: Miller (83) proposes $\kappa=\int{Tr[\exp{(-\beta\...
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Calculate optimal surroundings for given reaction mechanism to lower activation energy?

Let's take a reaction that's fairly well understood, which in this case means that the reaction mechanism is known, maybe something like this from here: If we know the reaction mechanism, we also ...
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How many different alkyl chlorides result from C4H10 and chlorine?

Let's say there's a reaction $\ce{C4H10 + Cl2}$ taking place under UV light. How many different alkyl chlorides do we obtain? I'm not sure if the resulting molecule would be monochlorinated or ...
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440 views

Magnesium powder + sodium carbonate solution: what happens?

I put magnesium powder into a sodium carbonate solution and it fizzed very slowly. The gas produced put out a lit splint immediately, which implies that carbon dioxide was released, but I cannot work ...
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Product of the following reaction

Thia is the question and my approach. I just want to confirm if it is the correct product. I have not gone for elimination as it will give anti-aromatic product.
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What drives intercalation?

From Wikipedia: intercalation is the reversible inclusion or insertion of a molecule (or ion) into compounds with layered structures. What is the "driving force" / mechanism that's responsible ...
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Reaction mechanism for ozonolysis

I have been trying to understand the reaction mechanism for ozonolysis but I am not able to understand what happens after the intermediate trioxolane is formed. I have searched online but didn't ...
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Electrophilic substitution in phenyl alkyl ether

Phenylalkyl ethers undergo usual halogenation in the benzene ring, e.g., anisole undergoes bromination with bromine in ethanoic acid even in the absence of iron (III) bromide catalyst. Why do we use ...
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What determines whether iodination or reduction will occur?

Alkyl Iodides are formed by reaction of alcohols with iodine and red phosphorus. I already am well aware that this forms $\ce{PI3}$ in situ, which acts similarly to $\ce{PBr3}$ and allows alkyl ...
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481 views

Differences in specific free radical reactions enthalpies

Iodination of alkanes using iodine $(\ce{I2})$ is usually an unfavorable reaction. Tetraiodomethane $(\ce{CI4})$ can be used as the iodine source for iodination, in the presence of a free-radical ...
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What is the mechanism for the oxidation of Cu(I) by ammonium nitrate?

I can't seem to find any resource online that describes the arrow pushing mechanism behind the oxidation of Cu(I) by ammonium nitrate in acid. Does a radical oxygen form? Or does it require both ...
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Is there wavefunction interference between alternate reaction pathways?

I'll give a specific example to clarify my question. If we look at the approach of chloromethylenecarbene's electron pair to cis-2-butene in the reaction of creating 1-chloro-2,3-dimethylcyclopropane, ...
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392 views

Simmons-Smith Cyclopropanation and Sterics

I know this is a Simmons-Smith reaction. Wikipedia tells me this: The Simmons–Smith reaction is generally subject to steric effects, and thus cyclopropanation usually takes place on the less ...
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Are there any suitable catalysts for ferric oxide and aluminum reaction?

As an exercise, I am trying to figure out how to catalyze the reaction of ferric oxide and aluminum Fe2O3 + 2Al -> 2Fe + Al2O3 I've been trying to find a substance A such that the reaction could be ...
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479 views

How to explain the different regioselectivity of ketones/imines reacting with LDA?

When 1 equivalent of LDA is reacted with, for example, 2-pentanone, you get the thermodynamic (more substituted) product. But when you react butan-2-imine with 1.0 LDA, you receive the kinetic (less ...
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410 views

Mechanism of an epoxide ring opening with trimethylaluminium

Am I right that there is a rearrangement reaction here? After coordinating the lewis acid to the oxygen, how do I come up with the correct rearrangement step?
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Why do we need sulfuric acid in reducing nitric acid?

From Wikipedia: Why do we need sulfuric acid in the left part of the formula? Wouldn't FeSO4 reduce nitric acid without the sulfuric acid taking part? P.S. I was answered that a milder form ...
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Mechanism: explanation of final step in synthesis of the thyroid hormones (T4, T3)

In the following mechanism for the synthesis of T3 (triiodothyronine) on thyroglobulin, what are the factors causing the last step to occur? Does it have something to do with the electron density of ...
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What is the reaction between diethyl malonate and hydrazine?

For the reaction of diethyl malonate with $\ce{NH2NH2}$ in aqueous medium in presence of $\ce{CH3CH2OH}$, I found two types of product with SciFinder: In presence of $\ce{H2SO4}$, the reaction ...
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Allylic bromination with NBS

I know that NBS is a selective brominating agent especially on the allylic position. And its reaction mechanism is of free radical. But I can't figure out the reason for the change in position of the ...
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Mechanism for synthesis of 4-nitrophenylhydrazine from the diazonium salt of 4-nitroaniline

I am trying to figure out the mechanism to create 4-nitrophenylhydrazine from the diazonium salt of 4-nitroaniline. I've found a couple of explanations for what reactants are used, but I don't ...
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849 views

Rust removal with phosphoric acid created more rust

I wanted to remove the rust on numerous steel parts with phosphoric acid. After removing all the grease in trichloroethylene, I put my parts into a 50 % solution of phosphoric acid ad 40 °C for 5 ...
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Why are trifluoromethyl diazirines so stable?

Why are trifluoromethyl diazirines so stable? Trifluoromethyl diazirines stability is well documented, however I am yet to find an explanation of why... Can it be homoaromatic or even aromatic? 2 pie ...
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Do carbon monoxide and graphene oxide react?

I want to know what happens if $\ce{CO}$ and graphene oxide (GO) react. Through the internet the reaction of GO with $\ce{H2O}$ is available but I did not find anything about carbon monoxide.
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Why is C=C launching electrophilic attack on Bromine instead of the other way round?

So during my lecture on reaction of Alkenes with Halogens, my lecturer used the example of $\ce{Br2}$ gas reacting with $\ce{CH2CH2}$. He mentioned that the $\ce{C=C}$ launches an electrophilic attack ...
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Computing initial reaction speed given reaction constant

Problem: $\ce{N2O}$ falls apart in oxygen gas and nitrogen gas according to a first order reaction rate. If you know that the rate constant is $0.38\ \mathrm{s^{-1}}$ at $760\ \mathrm{^\circ C}$, ...
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Please explain the mechanism of Cannizzaro's reaction

I did not completely understand the mechanism of Cannizzaro's reaction, especially the rate determining step i.e. the hydride transfer step, and the effect of electron withdrawing substituents on this ...
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Entropy of activation

In Price & Dwek, I find a small section discussing entropy of activation for three examples $$ 1: \ce{Ce^{4+}} + \ce{EDTA}^{4-} \rightarrow (\ce{CeEDTA})\\ 2, \text{S}_N\text{1 reaction}: \ce{AB} ...
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The increasing order of reactivity of substituted benz0yl chlorides towards nucleophilic substitution

Arrange the following compounds in the order of their increasing reactivity towards nucleophilic substitution: The answer to this question is $[3<2<1<4]$. We have to compare the positive ...
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102 views

Which step is the rate determining step in Benzyne mechanism - Elimination or Addition?

I have this doubt for a while now: How can we compare the reactivity of two compounds towards benzyne mechanism, which have different leaving groups (E.g. chlorobenzene and bromobenzene)? To know this,...
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440 views

Mechanism of Diels-Alder reaction

I have a question about the mechanism of the Diels-Alder reaction. Is this a two-electron or one-electron process as described by Fig (a) or (b) respectively or does not matter? How do we know that?
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In benzyne intermiediate of anisole why -I effect of OCH3 is considered not +M effect of it?

Here they considered -I effect of $\ce{OCH3}$ so carboanion is stable at orthroposition; But $\ce{OCH3}$ also shows $\text{+M}$ effect if $\text{+M}$ is shown carboanion will be stable at meta ...
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Determining the leaving group for substituted benzene in Aromatic nucleophilic substitution

I could figure out that After the substitution of one of the halogens, with the $\ce{-OCH3}$ group(Electron donating group), the ring would be deactivated towards nucleophilic substitution hence the ...
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Why doesn't acetic acid affect the formation of beta-nitroamine in nitro-Mannich reaction?

In a nitro-Mannich reaction, if we deprotonate a nitroalkane species with a strong base, then add acetic acid followed by an imine species, the reaction still proceeds giving the $\beta$-nitroamine. ...
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Why is ethanol, water and amonium needed for DMG to react with nickel?

I had this question on a test and I'm unsure on why ethanol is required for the reaction. I understand that you need the ammonia and water to make oxonium ions needed for the reaction to occur. We had ...
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Evaluating inductive effects in cyclic compounds

I was required to find the products on heating the hydroxide of; Now it's easy enough to find the answer; Hoffman elimination isn't going to happen from the methyl, and the n-propyl doesn't have $\...
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Why negative charge delocalises away from electronegative atoms

In the mechanism for the Wolff-Kishner reduction, after the $\ce{OH-}$ abstracts a proton, the resulting negative charge delocalises away from the nitrogen atom to the carbon, and the subsequent ...
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51 views

First step in a reaction between an acyl chloride and sodium acetate in acetic acid

What would the first step be in a reaction between acyl chloride and sodium acetate in the presence of acetic acid? I'm a bit confused because I'm not quite sure which step would occur first. I was ...
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46 views

On the relative ease of E2 dehydration

Concerning alcohol dehydration, I get that it's E1 in secondary and tertiary alcohols, that it's E2 in primary alcohols, and also why E1 reaction is easier for tertiary alcohols as compared to ...
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Using the steady state approximation in the decomposition of nitramide to determine rate law

$\ce{O2NNH2 (aq) ->[\mathit{k}_1] O2NNH- (aq) + H+ (aq)}$ $\ce{O2NNH- (aq) + H+ (aq) ->[\mathit{k}_{-1}] O2NNH2 (aq)}$ $\ce{O2NNH- (aq) ->[\mathit{k}_2] N2O(g) + OH- (aq)}$ $\ce{H+ (aq) + OH-...

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