In: Chemistry
QUESTIONS FOR m-Dinitrobenzene lab (Nitration of the aromatic molecules)
7) Explain why the meta product is formed and not the ortho or para.
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-Benzene is an aromatic compound and undergoes Aromatic electrophilic substitution reaction it means that it itself acts as nucleophile. Initially when the nitration is carried out using Conc. HNO3+ Conc. H2SO4 only all positions in benzene are identical and therefore we get only one product that is Nitrobenzene.
-Now, Nitrobenzene contains -NO2 group at ipso position and- NO2 is electron withdrawing group so makes benzene ring less nucleophilic. So, it deactivates the ring.
-Further being electronegative it generates positive charge at ortho and para by resonance. Now because of this +ve charge at o and p position the electrophile(also positive) will not attack at these positions and hence only m-product is formed. Here is the attachment for the resonance,