EFFECT OF THE RESOLUTION DEGREE OF EPR SPECTRA ON THE ACCURACY OF HYPERFINE STRUCTURE PARAMETERS DETERMINED FOR ISOTOPE SUBSTITUTED Zn-CHLORIN RADICALS

K. Dzilinski1, T. Szymanska1, R. Krzyminiewski2, G. N. Sinyakov3, A. M. Shulga3

1 Institute of Physics, Technical University, Czestochowa, Armii Krajowej 19, Poland,
2 Institute of Physics, A. Mickiewicz University, Umultowska 85, Poznan, Poland,
3 Institute of Molecular and Atomic Physics, Belorussian Academy of Sciences, Minsk, Belorus

Influence of the resolution degree of hyperfine structure on the accuracy of EPR parameters extracted from experimental spectra by using optimization procedures based of the least-squares method has been considered. EPR of Zn-octaethylchlorin radical anions and their deuterium substituted analogues have been analyzed. The shape of the least-squares function presented in 3-D space reveals limits of the accuracy for values of the parameters in the case of relatively large number of unequivalent paramagnetic centers. A method, based on convolution-deconvolution procedures of Fourier analysis, for enhancing the hyperfine structure resolution in the EPR spectra of selectively substituted and unsubstituted species has been applied.