Hello EasySpin community,
I have a more fundamental question about the nature of hyperfine coupling interactions between an electron and a spin-active nucleus, and I thought this would be the best place to ask. My understanding of HFC comes from NMR, where the coupling between proton nuclei, for example, causes splitting in the recorded spectrum. The intensity of each split differs based on the nearby nuclei that split the nuclei of interest in a particular way (picture included). In the example I've shown, the Hb signal centered at 5.76 ppm is due to the interaction with Ha when Ha1 and Ha2 have opposite magnitudes of I. Because there is statistically a higher chance of this being the orientation of Ha1 and Ha2 with respect to Hb at a given moment, the intensity of the resonance corresponding to this interaction is larger than the other two orientations.
Why is this not the case with EPR spectroscopy on metal complexes? I am showing an EPR spectrum of an S = 3/2 Co complex where the features corresponding to the 59Co HF interaction are all equal in intensity....Wouldn't we expect to see differing intensities based on the same principles from NMR? I haven't been able to find a concrete answer in EPR textbooks, but if there is a good reference that addresses this question, I would love to know. Thank you for your help!