Question

By citing specific data show that you could or could not distinguish between the two members of each pair of compounds by H-NMR spectroscopy.

A) dicyclohexylamine , dicyclohexylether

B) o-bromoanisole , m-bromoanisole

Answer 1

Solution :-

A) dicyclohexylamine , dicyclohexylether can be distinguiched using the NMR

because the dicyclohexylamine will give the peak for the amine proton at about 2.5 ppm

but sub peak will not be present in the dicyclohexylether

Also the dicyclohexylamine will show and extra peak for the NH proton than number of peaks for dicyclohexylether

so from this data we can distinguich them.

B)o-bromoanisole , m-bromoanisole are also distinguished using the NMR method because the both are anisoles but the postions of the Br are different therefore they will show little difference in the chemical shift of the aromatic protons. Also the coupling constants of the protons will be different so we can distinguish them.