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Rafael Nadal
Rafael Nadal
03:12
user image
what does this structure mean anybody please explain how deal with charges
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how is it aromatic explain ?
 
2 hours later…
Jasmine
Jasmine
05:36
@RafaelNadal it's aromatic as B has only 3 electrons in its valence shell and here all three are in bonding.aromatic as 4n+2 i.e 6 pi electrons are in resonance. It's cyclic and planar.
 
6 hours later…
Gaurang Tandon
Gaurang Tandon
11:38
"Resonance effects are generally far more superior to hyperconjugation" - Why? — Rahul 37 mins ago
Can anyone explain this? I just realized I don't have a very convincing explanation for that :/
Anonymous
12:02
@GaurangTandon Maybe because sigma bonds are stronger than pi bonds and hyperconjugation is also just another form of electron dispersion after bond breaking?
Anonymous
Like, hyperconjugation is a sort of no bond resonance.
Gaurang Tandon
Gaurang Tandon
14:46
hmmm
i don't find that very convincing though
i was looking for something along the lines of why does +M increase the electron density of benzene ring more than hyperconjugation
or maybe you're right
that's good
Anonymous
15:06
¯\_(ツ)_/¯
Abcd
Abcd
@GaurangTandon One of arenium's resonance structure with OH has complete octet of all atoms
@GaurangTandon Hyperconjugation $\ne$ octet.
Anonymous
'London forces are the forces that you should always consider in the end. They're like the slow pawns on the chessboard, their effect is negligible when the fast rooks and the industrious queens are around!' I like the way this statement is written!
Abcd
Abcd
@IceInkberry which book
Anonymous
Gaurang's answer
Anonymous
2
A: Boiling point trend in group 13

Gaurang TandonLondon forces are the forces that you should always consider in the end. They're like the slow pawns on the chessboard, their effect is negligible when the fast rooks and the industrious queens are around! In this case, our queens are the different structures of these elements. Let me first tell...

Anonymous
15:16
I don't think we can ever find such statements in books.
Abcd
Abcd
@Ice are you happy with my reasoning
@IceInkberry Hmm, now I understand why he got 91 in ISC english.
Anonymous
@Abcd I didn't understand the reference of hyperconjugation with octet. I mean, where did he mention that?
Abcd
Abcd
@IceInkberry you didnt get my reason then.
Anonymous
Oh nevermind :/
Abcd
Abcd
@IceInkberry In hyperconjugative structures octet of all atoms is not complete (in case of toluene)
In case of phenol octet of arenium ion's both carbon and resonance is complete because of resonance
@Ice do you know what arenium is?
Anonymous
15:22
Add one proton to benzene
Abcd
Abcd
@IceInkberry Do you know EAS?
Anonymous
@Abcd Electrophilic aromatic substitution. Yes.
Abcd
Abcd
@Ice sorry I am in a hurry right now thats why i wrote vague stuff. Will send the pictures of what I mean later at night.
But maybe @GaurangTandon would have understood it.
Anonymous
Alright, maybe later I will.
Rafael Nadal
Rafael Nadal
user image
please explain this structure why there are 2 -ve charges in this compound ?
Gaurang Tandon
Gaurang Tandon
15:36
@IceInkberry :D
@Abcd yeah, I did. I'll write a reply to Rahul later today
Gaurang Tandon
Gaurang Tandon
15:55
@RafaelNadal look up cyclooctatetradienyl dianion
Basically, the charge distribution is such that the ring ends up being aromatic
In case you don't know initially how the charge is distributed, you can always take a guess at various charge distributions and see which one satisfies huckel rule.
Gaurang Tandon
Gaurang Tandon
16:42
@Abcd I think that - even after the loss of H+ ion from the $\ce{-CH3}$ group - the resulting $\ce{-CH2-}$ anion still has complete octet of all the atoms involved (excluding the proton that got lost).
Abcd
Abcd
@GaurangTandon who will worry about the duplet of hydrogen
Gaurang Tandon
Gaurang Tandon
@Abcd of course, I will
:P
you're right
AbhigyanC
AbhigyanC
17:10
@GaurangTandon what grade are you in now?
you've written jee?
i ask this as a (potentially) fellow jee aspirant
Abcd
Abcd
@AbhigyanC He gave jee this year and has cleared it with a brilliant rank
AbhigyanC
AbhigyanC
@Abcd oh... did he share his rank?
i'd love to know
Abcd
Abcd
@AbhigyanC yeah 680 something
@AbhigyanC Are you in 12th
AbhigyanC
AbhigyanC
woah! that's amazing
@Abcd yeah
Abcd
Abcd
@AbhigyanC which coaching
AbhigyanC
AbhigyanC
17:17
allen.... are u an aspirant too?
Abcd
Abcd
@AbhigyanC yes
AbhigyanC
AbhigyanC
great! now i know i'm not the only jee aspirant on this stack exchange...
and i've a wonderful fellow aspirant
where do you study?
Abcd
Abcd
@AbhigyanC FIITJEE
Anonymous
17:54
@AbhigyanC Hey, I am from Allen too! Which branch?

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