any tricks for memorizing the directors?

[Xtian]

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anybody have any tips for memorizing the directors, activators and deactivators of rings?

--Frodo

 

[doc3232]

Basically if it has electrons it can donate them. That activates.
Br has electrons even though it is very electronegative, for example.

 

[IDoWhatIWant]

anybody have any tips for memorizing the directors, activators and deactivators of rings?

--Frodo

Look to see if the directly bonded atom is electronegative or not. If it's a O or N with (a) lone pair(s), then it is electron donating so it will activate the ring and direct O/P. If the directly attached atom is an atom attached to an electronegative atom, for example a carbonyl carbon or thionyl, then because the electronegative atom attracts (or steals or takes away) the electrons from the directly bonded atom, the atom directly attached to the benzene ring will be slightly positive. This causes it to WANT electrons, wanting to steal from the ring. So it will be deactivating, or M-directing.

The exceptions are the halides. When a halide is attached, it will be deactivating because they are electronegative. However, (this is just speculation which makes it easier for me to remember), because the atoms contain several lone pairs, it is O/P directing.

Basically look at relative electronegativities.

 

[klpennin]

Bonded directly to R, O, or N (except NO & NO2) - OP activators
Bonded to C (except for R group), or NO2 - M deactivators
Halogens and NO - OP deactivators

 

[Xtian]

ya'll ROCK!!!

Thanks,

Xtian