when is no2 considered -M or -I group?
Answers
Answer:
important to know that M effect always dominates I effect !
Explanation:
MESOMERIC effect is directional in nature it only operates in one direction which is permanent shift of pie electron cloud !
NOTE it is independent of distance .
whereas in INDUCTIVE it is wasn't directional ( it can operates in any direction) in operates through shifting of sigma electron cloud !
NOTE it depends on the distance .
so if there is change that delocalisation can be done only in one direction then consider M effect other than it will be I effect but if the distance is greater then inductive wont operate ! it is negligible after 2-3 atoms
there are more molecules like NO2 which -I as well -M eg. -CN, -CHO, -COR etc