What would be the order of electron density in the benzene ring in the following compounds?
Methyl Benzene
Ethyl Benzene
t-butyl benzene
I would say that t-butyl benzene would have the highest electron density as the alkyl group attached to it is bulkier than methyl and ethyl thus it will exert a greater +I effect pushing the electrons into the ring making it electron rich. Using same analogy ethyl benzene would have a greater electron density in the ring compared to methyl benzene.
However that is not the case. Something counter intuitive seems to be happening here. The order is methyl benzene >ethyl benzene >t-butyl benzene.
I think this phenomenon can somehow be explained using hyper conjugation, but i don't get it how?