A computer assignment technique for calculating chemical shifts and spin coupling constants from experimental highhyphen;resolution proton magnetic resonance spectra is described. The observed spectral lines are assigned to transitions within the energyhyphen;level diagram in a manner consistent with equalhyphen;spacing and intensityhyphen;sum rules. Experimental eigenvalues are calculated and introduced into equations derived from the spin Hamiltonian secular determinant in analytical form and in the diagonal experimentally observed form. These equations are implicit in the chemical shifts and spin coupling constants and in general must be solved by numerical methods although in some cases explicit solutions are found. The technique is applied to the 60 Mc spectrum ofohyphen;dichlorobenzene to obtain the results dgr;=15.23 cps,J12=8.17 cps,J23=7.44 cps,J13=1.61 cps, andJ14=0.36 cps.
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