Chemguide: Support for CIE A level Chemistry
Learning outcome 15.4(c)
This statement deals with the relative lack of reactivity of compounds like chlorobenzene compared with halogenoalkanes
Before you go on, you should find and read the statement in your copy of the syllabus.
The relative lack of reactivity of compounds like chlorobenzene compared with halogenoalkanes
The lack of reactivity of compounds like chlorobenzene is covered on the page about reactions of aryl halides. It is important that you follow the link in the section about the strength of the carbon-halogen bond to the introductory page about aryl halides. You can ignore the stuff about physical properties on that second page.
For exam purposes, CIE will ask you about the lack of reactivity of chlorobenzene in terms of the extra strength of the carbon-chlorine bonds. Don't use the additional explanation about the repulsion between the incoming nucleophile and the ring electrons.
If you are asked why chlorobenzene is unreactive towards nucleophiles, say "Delocalisation of a lone pair on a chlorine atom over the benzene ring strengthens the carbon-chlorine bond."
© Jim Clark 2014 (last modified June 2019)