| Abstract: | Abstract Lanthanide perchlorate complexes of the type Ln(pyaH)4] (ClO4)3 where Ln=Pr, Nd, Sm, Eu, Tb and Lu, and pyaH is pyrazinamide have been isolated. The compounds were characterized by chemical analyses, molar conductance, vibrational spectra, and electronic absorption and emission spectra. The vibrational spectra and molar conductances indicate that the perchlorate groups are ionic and that pyaH acts a bidentate ligand. The oscillator strengths of the transitions of the Nd(III) complex were determined in terms of the Judd-Ofelt theory. It was possible to use the modified Judd-Ofelt parameters, τλ, for the evaluation of the spectral intensities. In addition, a group-theoretical analysis of the emission spectrum indicates an effective site symmetry D2 for the Eu(III) complex between 77° K and 10° K. |
