Mössbauer spectroscopic investigation of some europium(III) diketonates

Abstract

A study is described of some europium(III) diketonate complexes in the solid state. Mössbauer spectra, taken with a ¹⁵¹Eu source in a Sm₂O₃ lattice, have been obtained over the temperature range 79–220 K. Measurements of relative intensities of europium(III) fluorescence following irradiation by near u.v. light are also reported. Isomer shifts are discussed in terms of the europium–oxygen bonding but no obvious correlation is apparent between fluorescence efficiency and overall covalency of the bonds revealed by the data. Intermolecular bonding in the complexes, as deduced from the temperature dependence of the Mössbauer resonant effect, is discussed; the results are consistent with available structural data.