21 Replies
@Dexter
Note for OP
+solved @user1 @user2... to close the thread when your doubt is solved. Mention the users who helped you solve the doubt. This will be added to their stats.2>1>4>3?
Yea tosyl etc. I think this is in the ncert lab manual
nvm not in ncert i guess. but yea clayden/solomons me hai
2 - benzenesulfonate ion (resonance stabilised anion with equivalent resonating structures)
1 - trifluromethylsulfonate (inductive effect stabilised anion with equivalent resonating structures)
4 - acetyl group (resonance stabilised anion with equivalent resonating structures)
3 - phenoxide (resonance stabilised anion with non-equivalent resonating structures)
I had the same answer as well
I suppose the answer key was wrong
Thanks
What does answer key say?
I>II>IV>III
Hmmm might be work checking out
Wait
*worth
Oh crap that's not a Tosyl group
That's benzenesulfonate
Ok, so the triflate ion is way more stable than the benzenesulfonate ion apparently
Triflic acid has a pKa of -14.7
Benzenesulfonic acid is a mere -2.8
But without the numbers, I have no clue how you would know
Triflic acid is trifluromethylsulfonic acid btw
I see
@iTeachChem sir any insights?
because this question is from a coaching module (resonance) so i doubt it would be solved only by looking at data
I suppose they've considered antihyperconjugation effects too....
Only thing I can think up
What i can think of is :
In triflate, during resonance the -ve charge is always placed on an oxygen atom but in benzenesulfonate the -ve charge is also placed on carbon atoms. Since oxygen atoms are more electro-ve they should handle the -ve charge better
As far as antihyperconjugation is concerned, never heard of it before
It's very rare
Although this shouldnt matter much in my opinion as the extent of resonance in benzylsulphonate is far far greater
Negative hyperconjugation
In organic chemistry, negative hyperconjugation is the donation of electron density from a filled π- or p-orbital to a neighboring σ*-orbital. This phenomenon, a type of resonance, can stabilize the molecule or transition state. It also causes an elongation of the σ-bond by adding electron density to its antibonding orbital.
Negative hyperc...
@Opt also in triflate backbonding takes place (CF3)
Backbonding? There aren't any vacant orbitals though?
Combined it seems as if this would make it a bette leaving group as oxygen is stabilised by resonance, carbon by backbonding
Oh yeah, mb. somehow got it messed up with CF+
this ones on me for distracting you :)
i usually do not have insights on oc :P
Alright then sir
+solved @Opt
Post locked and archived successfully!
Archived by
<@895699982265511976> (895699982265511976)
Time
<t:1744972635:R>
Solved by
<@763645886500175892> (763645886500175892)