IIT JEE , AIEEE Forum - Chemistry , Organic Chemistry

biki

we know that + M effect is shown by those groupswhich are attached to conjugated systems and have at least a lone pair of electron..........

..

= ^_ = ^_ A

but how can -CH₃group attached to benzene show +M effect and thereby direct electrophilic substituion in benzene towards ortho and para positions....

C-atom does not have any lone pair electron............Then how is it possible....

With what will the -CH₃ group show +M effect .... ??????

what will it shift towards the ring ...... ?????

Please show with diagrams...... if hyperconjugation or some other new phenomeno is involved...PLEASE

catch_arnnie

i think the O-P directing nature is due to the +I effect of the methyl group.

dip_xaverian

in the absence of any reactants the electron cloud in benzene remains as it is. But when the elctrophilic group approaches the cloud the the localization of the cloud is facilitated due to the +I effect of the CH3 group. The ortho and para subs take place just as all lone pair donating grps wud do.

arun-rashi

this is due to no bond resonance of methyl group in benzene ring so it develops negative charge on ortho and para position in benzene ring,this is interaction between sigama bond of carbon and hydrogen and pi-pi bond of C-C in benzene ring known as hyperconjugation.

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