explane as to why haloarenes are much lass reactive than the haloalkanes towards nucleophilic substitution reaction?
explane as to why haloarenes are much lass reactive than the haloalkanes towards nucleophilic substitution reaction?
Dear student!
Haloarenes are much less reactive than haloalkanes towards nucleophilic substitution reactions because, in haloarenes, the benzene ring undergoes resonance and as a result, the C−X bond acquires a partial double bond character and also the de localization of electrons creates more electron rich center so that a neucleophile which is proton or nucleus loving could not attack on such species and therefore, it becomes difficult to break the C−X bond.
While,in haloalkanes, the halogen atom is attached to an sp3 hybridised carbon atom while in haloarenes, it is attached to an sp2 hybridised carbon atom. Since an sp2 hybridised carbon has more s-character than sp3 hybridised carbon, the haloarene is more electronegative than the haloalkane. As a result, the neucleophile could attack on less electronegative haloalkanes C-X bonds and thus it becomes more reactive.
Dear student!
Haloarenes are much less reactive than haloalkanes towards nucleophilic substitution reactions because, in haloarenes, the benzene ring undergoes resonance and as a result, the C−X bond acquires a partial double bond character and also the de localization of electrons creates more electron rich center so that a neucleophile which is proton or nucleus loving could not attack on such species and therefore, it becomes difficult to break the C−X bond.
While,in haloalkanes, the halogen atom is attached to an sp3 hybridised carbon atom while in haloarenes, it is attached to an sp2 hybridised carbon atom. Since an sp2 hybridised carbon has more s-character than sp3 hybridised carbon, the haloarene is more electronegative than the haloalkane. As a result, the neucleophile could attack on less electronegative haloalkanes C-X bonds and thus it becomes more reactive.
