The Determination of the Triplet State Energy of the Ligands and the Study on Sensitization to the Rare Earth Ions

Seven kinds of rare earth complexes with good film-formed properties were synthesized.The phosphorescence specra of gadolinium complexes at low temperature were measured and the triplet state energies of ligands with different alkyl chain length were claculated.The effect of the energy matching between the ligands and the center rare earth ions on the luminescence properties of the complexes was also discussed.It was found that for these compounds,the luminescence intensities increased with the decreasing the energy differences between the triplet state energy of ligands and excited state energies of center rare earth ions.This result can provied a convenient and reliable method to design and seek amphiphilic rare earth complexes with strong fluorescence properties.