Synthesis, luminescence, energy transfer of binary and ternary rare-earth complexes with 5-sulfosalicylic acid and 1,10-phenanthroline

A series of binary and ternary complexes of rare earth (Gd, Eu, Tb) with 5-sulfosalicylic acid and 1,10-phenanthroline were synthesized. The low-temperature phosphorescence spectra and lifetimes of these complexes were measured. The triplet level energies of ligands were determined and the energy match between the triplet state energies of ligands and the resonance emitting energies of Ln(3+) was discussed. The intramolecular energy migration in the complexes tvas studied in detail. The luminescence intensities and luminescence lifetimes were also obtained and in good agreement with the theoretical prediction of luminescence properties.