Which is better nucleophile

Are nucleophiles Lewis bases? What is a nucleophilic substitution? How does the reactivity of a nucleophile change across a row in the periodic table? What is an ambident nucleophile? Is ethoxide a better nucleophile in methanol or acetone? How does sodium hydroxide react with chlorobenzene? How do you generate a good nucleophile? Why do amines act as nucleophiles? How do amines react? Which is more reactive towards nucleophilic attack, an aldehyde or a ketone?

Give at least one reason why. Which of following carboxylic acid derivatives is most reactive towards nucleophilic substitution? Is HBr a nucleophile? What is the difference between a base and a nucleophile?

What is an electrophile? How would you tell the difference between a good and poor nucleophile from the molecular formula? Which is not a good nucleophile, phenoxide ion or acetate ion?

Is chlorine more nucleophilic than iodine? Why does Cyanide only react in SN2 reactions? Is there a molecule which behaves as both nucleophile and electrophile? Can NaOH be good nucleophile? Is nitrogen more nucleophilic than oxygen?

Why is pyridine a poor nucleophile? What is the difference between an electrophile and a nucleophile? What is the difference between an acid and an electrophile? How does doubling the concentration of nucleophile affect the rate of a reaction with an SN1 mechanism?

What is the mechanism for nucleophilic substitution between butyl- iodide and NaCN? Reference: Nucleophilic strength. So, would R-O-NH2 be a fair nucleophile or a weak nucleophile? If the iodide ion is a stronger nucleophile than the hydroxide ion, why does the latter displace the former in a reaction involving aqueous Sodium hydroxide and alkyl iodide?

Than iodide is able to replace OH group. Pingback: Electrophiles and Electrophilic Reactions: What makes a good electrophile?

Hi, I am quite confused I ampretty sure in an SN2reaction I- would be a good electrophile not nucelophile? Click here. What are strong nucleophiles? Strong nucleophiles: This is VERY important throughout organic chemistry , but will be especially important when trying to determine the products of elimination and substitution E1, E2, SN1, SN2 reactions.

Share this: Facebook Twitter Pinterest Print. There are three factors that make strong nucleophiles. You see all of it in there, but the bottom line is that there are protons that can react with other things.

Let me clear this away so that I have some real estate. Let me just write down water. Water is a protic solvent. Now, wait. Is that always the case? It seems like hydrogens are everywhere. Well, no, it's not always the case.

Let me show you an aprotic solvent. Diethyl ether looks like this. And just so you know the naming, it's an ether because it has oxygen, and it's diethyl because it has two ethyl groups. That's one ethyl group right there and that is the second. So it's diethyl ether. Now, you might say, hey, this guy's got hydrogens lying around as well. Maybe those can get released.

But, no, these hydrogens are bonded to the carbon and carbon is not anywhere near as electronegative as oxygen. Carbon is unlikely to steal these hydrogens' electrons and these hydrogens to be loose. If they were bonded to the oxygen, that would have been a possibility.

With water, you have obviously H-O-H. In alcohols, you have some maybe carbon chain bonded to an oxygen, which is then bonded to a hydrogen.

So in either of these cases, in either water or alcohol, you have these hydrogens where the electron might be taken by the oxygen because it's so electronegative and then the hydrogen floats around. Anyway, that's a review of protic versus aprotic.

In a protic solvent-- and this is actually a general rule of thumb-- if a nucleophile is likely to react with its solvent, it will be bad at being a nucleophile. Think about it. If it's reacting with the solvent, it's not going to be able to do this.

It's not going to be able to give its electrons away to what it needs to give it away, to maybe what we saw in an Sn2-type reaction. In a protic solvent, what happens is that the things that are really electronegative and really small, like a fluoride anion-- let me draw a fluoride anion.

In a protic solvent, what's going to happen is it's going to be blocked by hydrogen bonds. It's very negative, right? It has a negative charge. And it's also tightly packed. As you can see right here, its electrons are very close, tied in.

It's a much smaller atom or ion, in this case. If we looked at iodide, iodide has 53 electrons, many orbitals. Actually, iodide would have It would have the same as iodine plus one.

Fluoride will have 10 electrons, nine from fluorine plus it gains another one, so it's a much smaller atom. So when you have water hanging around it, let's say you have something like water. That has a negative charge. Water is polar. Actually, both of these are polar, so I should write down polar for both of these. This is a polar protic solvent. This is a polar aprotic solvent. In this case, water is still more electronegative than the carbon, so it still has a partial negative charge.

These parts still have a partial negative. Water still has a partial negative charge. The hydrogen has a partial positive charge so it is going to be attracted to the fluorine.

This is going to happen all around the fluorine. And if these waters are attracted to the fluorine in kind of forming a tight shell around it, it makes it hard for fluorine to react.

So it's a worse nucleophile than, say, iodide or hydroxide in a polar protic solvent. Hydroxide has the same issue. It's still forming hydrogen bonds, but if you wanted to compare them, iodide is much bigger. Maybe I'll draw it like this.