Question

i need help understanding this. From what I know more reactive is less stable. Isn't it better to have a carbocation next to a EDG group instead of a EWG. Therefore, if the carbocation ends up next to a EDG group it will be more stable which is less reactive?

Arrange the following carbocations in the order of increasing reactivity (3 pt): Br CI NH2 NO2 OHC

Answer 1

The Carbocation next to EDG (Electron donating group) is better in terms of Stability than the Ewa. (Electron with drawing group) AS EDG group donates I it electron density to Carbocation, the carbocation become more stable, so it become less reactive with other molecules BV T Above all the three structure contain electron withdrawing donating groups, which Stabilise as destabilize the Carbocation The Halogen group which are generally more electronegative (EWG) because they Stabilize positive charges. Because each of this atom have lone pair which can be donated to the Carbocation which is Stabilizing interaction Scanned with ~ Camiscatter

NH, group is electron donating group vehich stabilize the carbocation and No 2, Och, group are ENG which destabilize the carbocation by withdrawing the electron density In the above structure, B; NO2 is directly attached to Carbocation , which destabilize the carbocation more than other group OHC - group is not directly attach to Carbocatio so it will destabilize the Carbocation less than - Nor group - The Structure A is more stable, deca of EDG. The structure 8 is less stable because structure A The structure o is more stable than Structure B Inductive effect mesomeric effect play important role in stability of cation. As we conclude that order of increasing - reactivity, (by stability & reactivity relation) Br Onha CHO o est come carbocation in increasing order of reactivity onor CamScanner

Carbonation are more stable when they are attached to electron donating group (EDG) . They stabilize it by by donating electron density to carbonation.

Electron withdrawing group (EWG) , destabilize the carbocation by withdrawing electron density form atom.

In this question , NH2 is the EDG ,and NO2 and CHO is the EWG .

The halogen are electronegative ,but they stabilize the carbocation by donating the electron pair.

As we know ,the more stables is reactant , it is become less reactive and vice versa.

The structure A is more stable so it is less reactive, than structure B,C

The structure B is the less stable so it is the most reactive.

Carbocation end up next to EDG , become more stable and less reactive than EWG .

The inductive effect and mesomeric effect play important role for identifying stability of carbocation.

Incresing order of reactivity for above A ,B, C structure is

A→ C → B