CJ122638

Member
10+ Year Member
Jun 7, 2006
58
0
Status
Dental Student
Does anyone have a mnemonic or some other trick to easily remember which groups are O/P directing and which are M?
 

RozhonDDS

10+ Year Member
7+ Year Member
Jan 2, 2006
505
0
Syracuse
Status
Dental Student
R groups, oxygen bonded to benzene carbon, nh2, carbonyl groups bonded with either an N or O to the benzene and most halogens=ortho/para

Carbonyl groups with the C bonded to the benzene, no2, no3, nitrile, nh3 and some other stuff=meta
 

SgtSadhu

Member
10+ Year Member
5+ Year Member
Jun 14, 2006
49
0
Status
Pre-Dental
CJ122638 said:
Thanks so much!

I know this isnt the best way to explain it, but the way i remember it is

if there is an O or any other electronegative group first attached to it, it will be electron donating and ortho and para directing (benzene-OCH3)

*Note: if the atom attached to the one directly on the ring is more electronegative, it will be deactivating ( benzene- N02)

If there is a halogen, its ortho and para deactivating (Benzene-Cl)

if there is an atom, like a C, and an electronegative atom is attached to that, it will be meta deactivating (beneze-COOh)