Solid state photoluminescence of novel lanthanide complexes based on 4-benzoylpyrazolone Schiff base

A novel, promising ligand for luminescent lanthanide complexes tris-((4-(3-methyl-1-phenyl-5-pyrazolonyl)-phenylmethylidene)-2-aminoethyl)amine (trenPMBP) was prepared and used as effective “antenna” for the ligand-sensitized photoluminescence of Tb3+, Dy3+ and Sm3+ ions. All the complexes show surprisingly intensive photoluminescence in comparison with their simple 4-benzoyl-3-methyl-1-phenyl-5-pyrazolone analogues. One of the reasons of such result can be a relatively high located triplet energy level of trenPMBP around 22675 cm−1, which properly fits with the emissive energy levels of Tb3+ and Dy3+ (20430 cm−1 and 20830 cm−1, respectively), thus avoiding back-energy transfer from the lanthanide to the ligand.