The EPR Spectroscopy of the Melts of Copper(II) Coordination Compounds with β-Diketones

The results of EPR studies of the melts of copper(II) beta-diketonates and their hexacoordinated complexes with organic donor bases are presented. It is found that the high-temperature spectrum of the magnetically concentrated melt shows the HFS from the copper nucleus, in contradiction with the commonly accepted point of view on the temperature dependence of the EPR-spectrum shape. The studies of the temperature dependence of the EPR-line width both for the melts and solutions of these compounds made it possible to interpret the observed phenomena in terms of the structural features of the melts and explain them by the presence of a sizable ligand shell in the complexes with the branched alpha-substituents. The EPR studies of the melts of hexacoordinated complexes with donor ligands showed that the process of thermal decomposition occurs either through the step of elimination of the donor base molecules or through the step of opening the chelate ring of the beta-diketonate ligand.