Use of Spin Inversion Operators to Describe Properties of Nuclear Magnetic Double-Resonance Spectra

Abstract

For general spin systems of the type $A_m{A}_{m^{\prime }}^{\prime }{\mathrm{···M}}_n{M}_{n^{\prime }}^{\prime }{\mathrm{···X}}_p{X}_{{}^{\mathrm{p\prime }}}^{\prime }\mathrm{···}$ , it is shown that nuclear magnetic double‐resonance spectra recorded by sweeping magnetic field are mirror images if the frequency of the strong radio‐frequency field is set at equal intervals Δ above and below the resonance frequency of one type of nucleus. It is further proven that the double resonance spectrum is symmetric for Δ=O when field is swept, and for all values of Δ when frequency is swept. Finally, it is shown that the relative signs of all the coupling constants between nonequivalent or magnetically nonequivalent nuclei in a spin system can, in principle, be obtained in a double resonance experiment.