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### Stability of the alkenyl and phenyl cations

One reason often cited for why alkenyl and phenyl halides do not undergo nucleophilic substitution by the $\ce {S_N1}$ mechanism is that the formation of the alkenyl and phenyl cations involve a ...
60 views

### Organic chemistry, hybridization concept [closed]

Hybridization of phenyl cation and venyl[sic] vinyl cation and acetylene cation ,I am totally confused , I think that the hybridization of both phenyl and the venyl cation is SP , I think that in both ...
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### Perpendicular orbitals in aryl and vinyl carbocations? [duplicate]

This point (iv) has been given under reasons for extremely low reactivity of aryl and vinyl halides. I cannot understand it. First of all, isn't the positive carbon atom in phenyl as well as vinyl ...
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### Stability of carbocation on doubly bonded carbon [duplicate]

What can be said about the stability of the following carbocation? I think that it would have something to do with hybridisation as, clearly one carbon is sp hybridised and the other is sp2. Can ...
262 views

### On the stability of carbocations

I have a question regarding the stability of carbocations. It is shown below. I am confused between options II and III. The structure shown in option II has more resonance structures. Thus, I ...
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### Accounting for Vinylic Carbocation instability [closed]

I read that due to geometrical constraint, positive carbons in an aryl carbocation exhibit sp^2 hybridization instead of sp^1. The empty p-orbital is forced into a hybridized position via geometrical ...
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### Why is SN1 mechanism followed in diazo aromatic compounds' nucleophilic substitution?

There is considerable evidence that SN1 mechanism is followed in diazo aromatic compounds' nucleophilic substitution. I would like to know the reason for this and why is it preferred to SNAr mechanism ...
22k views

### Carbocation stability order

I was wondering whether the following order (from here) is correct: In the first inequality, why did 9 hyperconjugations dominated resonance effect of benzene ring? In the last inequality doesn't ...
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### Do vinyl cations adopt a classical or non-classical structure?

Whilst reading this question today, I remembered something that I had seen previously here. In the second linked question, @Martin provided a reference to suggest that vinyl cations actually adopt a ...
9k views

### Why are sp hybridized carbocations high energy?

You don’t see carbocations on double bonds very much, and here's a good reason: compared to sp3, there is more s character in the orbitals, so the empty orbital is held more closely to the nucleus. ...
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### Resonance in benzenylium cation [duplicate]

Why is this type of resonance not possible? My book says that the positive charge is localised, and resonance is not possible. But I have drawn the resonance structures (though you can note that the ...