Sn2 Reactions and Solvent characteristics

  • Thread starter Thread starter PainDoc
  • Start date Start date
  • Tags Tags
    Reactions Solvent
AI Thread Summary
SN2 reaction rates are influenced by the polarity of the solvent based on the charges of the nucleophile and electrophile. When both reactants carry a formal charge, a moderately polar solvent enhances the reaction rate. Conversely, if both reactants are neutral, a highly polar solvent is more effective. This is due to the stabilization of the charged transition state by polar solvents, which lowers the activation energy. Understanding these solvent characteristics is crucial for optimizing SN2 reaction conditions.
PainDoc
Messages
2
Reaction score
0
I am having trouble figuring out why this statement is true, especially the bolded sentence:

"When the nucleophile and/or electrophile have a formal charge, SN2 reaction rate is fastest when the solvent is of modest polarity. When the nucelophile and electrophile are both neutral, SN2 reaction rate is fastest when the solvent is highly polar."
 
Physics news on Phys.org
Look at it this way: we have situation when both reagents and products are neutral and thus destabilized by the charged solvent (green line). The transition state, on the other hand, where there is a significant charge is present is stabilized by polar solvent, so reaction goes faster, because activation energy for the rate determined step is decreased.
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    5.7 KB · Views: 506
Thread 'Confusion regarding a chemical kinetics problem'

Thread 'Confusion regarding a chemical kinetics problem'

TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
View full post »

Thread 'Prove that evolution is constant (Provide at least two arguments to support your position)'

I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
View full post »

Similar threads

Chemistry How to Identify HOMO and LUMO in an Sn2 Reaction?
Replies
10
Views
3K
Which Major Pathway Predominates for This Organic Reaction?
Replies
2
Views
2K
Which Factors Determine the Rate of SN1 and SN2 Reactions?
Replies
1
Views
9K
SN2 & SN1 Reactions: Solvent Effects Explained
Replies
5
Views
10K
Organic Chemistry: Sn1/E1/Sn2/E2/Alchol/Ether Transformations
Replies
3
Views
8K
Ochem: H2O & HBr Reactions 2nd Semester Organic Chemistry
Replies
1
Views
5K
Which Compound Undergoes Unimolecular Substitution Fastest?
Replies
2
Views
6K
What Are the Common Solvents Used in Chemical Reactions and Why?
Replies
5
Views
3K
Polar aprotic solvent sn2 rate
Replies
1
Views
19K
Strong Acid Reactions: Explaining HCl + H2O → Cl- + H3O+
Replies
3
Views
5K

Hot Threads

Recent Insights

Back
Top