The uses of ENDOR spectroscopy in transition metal and polymer chemistry.

There has recently been an increase in the amount of work on the theoretical side of ENDOR spectroscopy which has tried to give a more detailed understanding of the complex spectra obtained from solid solutions. The work presented here is an attempt to show how much more information can be extracted from such spectra with only a minimal increase in the amount of experimentation required. A simulation program is presented which, based on a simple model, predicts the form of the variation of the ENDOR spectra when the field Bo, at which the experiment is performed, is varied within the span of the ESR spectrum. These theoretical results are compared with the results from a study of the complex bis-(pentan-2, 4-dionato) oxovanaduim (IV). The results indicate that not only can we obtain more accurate values for the principal elements of the hyperfine interaction tensors, but that we can extract information as to the relative orientation of the g axis system and the axis system of the hyperfine interaction tensor. two copper complexes, bis-(pentan-2,4-dionato) copper (II) and bis-(2,2,6,6-tetramethylheptan-3,5-dionato) copper (II), and these results are compared with results from solid solution ENDOR spectra of the two complexes obtained by the author and by other workers. The comparison indicates that a certain amount of reinterpretation is required in the case of the published work on the bis-(pentan-2,4-dionato) copper (II) complex.