Table $2\mathrm{.}1$ NMR data for the salen derivative compound in containing TMS at $300K.\frac{0}{p}pm{m}^{**}$

NMR $($CDCl$3300MHz),$ ddd$,),7\mathrm{.}25($residual NMR solvent

peak$),7\mathrm{.}08(2H,dd),6\mathrm{.}82(2H,dd),6\mathrm{.}72(2H,ddd),3\mathrm{.}73(4H,s),0\mathrm{.}00($TMS standard reference

compound$)$

What can you deduce from the fact that the peak in the NMR spectrum at $13\mathrm{.}20ppm$

disappears on shaking the solution with D$2$O$?$

Assign the peaks in the NMR spectrum for the compound, noting that it is not possible to assign the

aromatic signals unequivocally. You should, however, comment on how the multiplicity of these peaks

can enable you to suggest two possibilities each for their assignment.

Tenting is observed for the signals at $7\mathrm{.}16$ and $6\mathrm{.}72ppm.$ What does this suggest in terms of the

relative arrangement of the protons from which these signals arise?

Considering the structure of the compound, discuss whether the number of proton signals observed

in the NMR spectrum and their relative integrals are what you would expect for this ligand