[jiujitsu123]

IS this correct

when nitrobenzene undergoes chlorination is it Meta-chloro-nitrobenzene

since NO2 is a meta deactiving group...

[madscientist]

Your right but I think it would be written as 1-chloro-3-nitrobenzene

[Custos]

IS this correct

when nitrobenzene undergoes chlorination is it Meta-chloro-nitrobenzene

since NO2 is a meta deactiving group...

Yes, but the reason is not quite right. The nitro group is electron withdrawing so it will deactivate the ortho and para positions to electrophilic attack (which chlorination is) through conjugation. Hence the chlorination, if forced, will go in the meta position.

Read this for a good explanation: http://www.cem.msu.edu/~reusch/VirtualText/benzrx1.htm

[english]

It's best understood if you think of what the benzene ring looks like, essentially a donut of pi electrons above and below the sigma network.

Nucleophiles cannot approach this plane, unless of course, there is a group somehwere on the ring that can actively withdraw those pi electrons away from the site where you want your nucleophile to create a new bond.

It turns out the deactivating group must be in the o or p positions.  At the m position, pi electrons cannot "move" onto your deactivating group.


Vinyl halides follow the same unreactivity in substitution reactions.

[AWK]

[
Yes, but the reason is not quite right. The nitro group is electron withdrawing so it will deactivate the ortho and para positions to electrophilic attack (which chlorination is) through conjugation. Hence the chlorination, if forced, will go in the meta position.

Read this for a good explanation: http://www.cem.msu.edu/~reusch/VirtualText/benzrx1.htm

NO2 group deactivte all position of benzene ring, but ortho and para are deactivated more than  meta.