Structural information from powder ENDOR spectroscopy. Possibilities and limitations

Abstract

The methodology for extracting structural information from powder ENDOR spectra is briefly reviewed. The procedure, based upon tensor transformation of hyperfine data obtained from spectra recorded at the EPR ‘turning points’, is described in some detail, whereas other techniques, such as fitting of spectra obtained as a function of the observing field, are only mentioned. Examples from the recent literature are presented and discussed. It is shown that in many cases single-crystal measurements do not offer appreciable advantages, as far as the geometry of magnetic nuclei surrounding the paramagnetic probe is concerned.