Questions tagged [nucleophilicity]
For questions involving the nucleophilicity of a chemical species. Not to be confused with "basicity", use the [acid-base] tag instead.
24
questions
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1answer
28 views
Why is N- a better nucleophile than S-?
I can't rationalize why S- is a worse nucleophile than N-. I thought nucelophilicity was related to electronegativity, the more electronegative an atom is, the less of a nucleophile it is. Sulfur is ...
2
votes
1answer
31 views
Why polar aprotic solvents don't surround negatively charged nucleophiles?
Protic solvents can form a tight shell around a nucleophile. But what's stopping any polar solvent from doing so? Shouldn't a polar solvent surround negatively charged $\ce{F-}$ with its partially ...
0
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1answer
47 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 ...
5
votes
3answers
112 views
Nucleophilicity in polar aprotic solvent (DMSO)
The strength of a nucleophile in polar aprotic solvent is proportional to its basicity. Lone pair on O- in the molecules will donate an e- pair to an atom. I'm not sure why the alkene ring in 2 makes ...
1
vote
0answers
51 views
Reactivity towards nucleophillic addition
Phenyl ethanal or ethanal
I thought phenyl methanal is less reactive towards nucleophilic attack due to presence of bulky group. But answer in my book suggest ethanal is less reactive.
Para-...
0
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0answers
45 views
Formation of isocyanide on reaction with silver cyanide whereas sodium cyanide forms a regular cyanide
Organic halide react with silver cyanide and an isocyanide is formed, whereas on reaction of sodium cyanide, normal cyanide is found.
What is the reason behind the difference in the products??
In a ...
1
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0answers
105 views
Nucleophilicity methanol vs water [closed]
I have a short question: Which among Methanol and water will be a better nucleophile for a reaction carried out in some polar protic solvent .
Searching over the internet suggests that methoxide ion ...
4
votes
1answer
42 views
Nucleophilic nature of ions
Consider the following species:
$$
\underset{(\text{A})}{\ce{\overset{⊖}{O}H}}
\quad
\underset{(\text{B})}{\ce{CH3-\overset{⊖}{O}}}
\quad
\underset{(\text{C})}{\ce{\overset{⊖}{C}H3}}
\quad
\...
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0answers
151 views
Nucleophilic addition - Propanal vs Benzaldehyde
According to my school textbook, carbon atom of the carbonyl group benzaldehyde is less electrophilic than that of propanal because polarity of the carbonyl group is reduced in benzaldehyde due to ...
1
vote
0answers
266 views
Better nucleophile OH- aur OCH3- in aqueous medium
Which of the two, Hydroxide anion OH- and Methoxide ion OCH3-, is a better nucleophile in aqueous medium?? I have 2 arguments both against each other.
First, Oxygen atom in methoxide has higher ...
2
votes
2answers
602 views
Order of Nucleophilicity
I know this question has been asked many times but I need to confirm this doubt which has been pestering me for the past few days.
Suppose in an $\mathrm{S_N2}$ reaction (in polar aprotic solvent) we ...
4
votes
1answer
341 views
Why is fluoride the most nucleophilic halide in aprotic solvents? [duplicate]
I am confused on the topic of electronegative nucleophiles, and polar aprotic solvents.
From my understanding, the more electronegative a nucleophile is, the weaker of a nucleophile it will be, ...
1
vote
3answers
2k views
Why does using NaI as a nucleophile and acetone as solvent lead to an SN2 reaction mechanism instead of SN1? Is I- not considered a weak nucleophile?
In a reaction with a secondary leaving group, why does using $\ce{NaI}$ with acetone as a solvent lead to an $\mathrm{S_N2}$ reaction mechanism instead of $\mathrm{S_N1}$? I thought that halogens were ...
0
votes
1answer
55 views
Difference in leaving group ability due to variation in nucleophiles
Wikipedia writes:
There can still exist contextual differences in leaving group ability in the purest form, that is when the actual group that leaves is not affected by the reaction conditions (by ...
0
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0answers
508 views
Electrophilic addition of IBr to alkene
I would assume options A and B are possible products due to the $\ce{I+}$ electrophile attacking the alkene, and hence are ruled out.
However, I am torn between options C and D. Both products are ...
1
vote
2answers
1k views
Which will give faster SN2 reaction
In $\ce{H2C=CH-Br}$ and $\ce{H3C-CH2-Br}$, which will react faster towards a $\mathrm{S_N2}$ reaction?
According to me, as double bond exhibit −I effect, hence the 1st should do a faster reaction. Am ...
1
vote
1answer
703 views
Nucleophiles in protic and aprotic solvent [closed]
If the nucleophiles have almost same size (not a large difference) such as $\ce{C- , N- , O-}$ then how their nucleophilicty varies in protic and aprotic solvents?\
Does it depend on types of ...
3
votes
0answers
178 views
Nucleophilicity of halides in solvents [duplicate]
I have studied that as electronegativity increases nucleophilicity decreases. But in the aprotic solvent the order of nucleophilicty is: $$\ce{F- > Cl- > Br- > I-}$$ but how is this possible ...
1
vote
0answers
58 views
How can a weak base act as a strong nucleophile (and vice versa)?
Carboxylate ion ($\ce{RCOO-}$) is a weak base as the negative charge on oxygen is delocalised due to resonance. So, it has less tendency to donate lone pair of electrons to H+ ion. Similarly, it has ...
13
votes
2answers
1k views
Is hydrazine a better nucleophile than ammonia?
Which is a better nucleophile, $\ce{NH3}$ or $\ce{NH2NH2}$? For the sake of limiting scope, I want an answer for behavior in a protic solvent though non-protic solvent answers are welcomed.
My logic ...
9
votes
2answers
718 views
Which is a better nucleophile: hydroxide anion or amide anion?
I know that nucleophilicity order depends on what type of solvent we take, polar protic or polar aprotic and also on the basicity of nucleophile.
In DMF, which is a better nucleophile $\ce{NH2-}$ ...
3
votes
4answers
3k views
How to determine the order of nucleophilicity for given chemical species?
How to determine the order of nucleophilicity for given chemical species?
Like I came across this question, to rearrange $\ce{RCOO-, OR-, OH-, H2O}$ (alkyl acetate, alkoxide, hydroxide, and water) in ...
12
votes
2answers
692 views
Nucleophilicity with respect to the solvent
I am currently studying nucleophilicity of molecules and am getting a set of conflicting information, so I wanted to clarify nucleophilicity trends with respect to solvent.
Master Organic Chemistry ...
6
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3answers
27k views
How to determine order of nucleophilicity among commonly used nucleophiles?
How to determine order of nucleophilicity among commonly used nucleophiles? For example, in Finklestein reaction, $\ce{NaI}$ (reagent) - taken in acetone (solvent) - displaces $\ce{SH-}$ ion from ...
