Knowledge Bank

The high resolution proton magnetic resonance spectrum of mercury diethyl has been studied at both 40 mcs and fid 60 mcs. The spectrum of this compound can be satisfactorily interpreted as an $A3B2$ system. The ratio of the spin coupling constant J to the internal chemical shift $\delta$ between $CH3(A)$ and $CH3(B)$ groups is about 0.73 at 40 mcs and about O.49 at 60 mcs. The presence in the sample of the fairly abundant $Hg199$ isotope (with nuclear spin $I=1/2$) makes possible a direct determination of both the J and $\delta$ values for this compound despite the complexity of the spectrum Theoretical calculations of the line frequencies and relative intensities have been made and the agreement with experiment is satisfactory. Details of the theoretical method for calculating line frequencies and relative intensities of the NMR (nuclear magnetic resonance) spectrum of an $A3B2$ system (with nuclei of nuclear spin $I=1/2$) are also given.