Intensity Analysis and Luminescence Spectra of Non-Aqueous Solutions of Europium Compounds

The oscillator strengths of the f-f transitions as well the fluorescence spectra for europium Perchlorate, chloride and nitrate in mono- and disubstituted amides have been measured. The Judd-Ofelt parameters are calculated. The formation of inner-sphere europium complexes is discussed on the basis of intensity analysis of the absorption and luminescence spectra. In mono- and disubstituted amides solutions the f-f transitions of Eu+3 have been analysed and the three parameters fitted with satisfactory accuracy. Among all f-f transitions the hypersensitive ones in absorption 7 F0 → 5 D0 and fluorescence 5 D0 → 7 F2 varied most markedly. From an analysis of the data it was concluded that only Eu(NO3)3 and EUCl3 in DMF form inner-sphere complexes. At low concentration of EUCl3 in DMF the predominant form is [EuCl(DMF)y−1]+2 , whereas at high concentration the predominant form is [EUCl2(DMF)y−2]+1 . The intensity of the hypersensitive bands decreases with increasing EUC1 3 concentration, contrary to the common opinion that complexation increases the intensity of hypersensitive bands.