Synthesis and photoluminescence properties of novel lanthanide complexes based on pyrazolone Schiff bases

Synthesis and spectroscopic characterization of novel lanthanide complexes, based on tripodal ligands prepared by reaction of 3-aryl/heteroaryl-4-benzoyl-1-phenyl-5-pyrazolone (where aryl/heteroaryl = phenyl, 2-pirydyl or 2-thienyl) with tris(2-aminoethyl)amine (TREN) are reported. All of the new Schiff base-type ligands have relatively high located triplet energy levels in comparison with their simple β-diketonate analogues. All of them were used as “antennas” for the ligand-sensitized photoluminescence of Tb3+ ion and in two cases (aryl/heteroaryl = phenyl and 2-pirydyl) characteristic green photoluminescence was detected.

Novel terbium and gadolinum complexes, based on tripodal Schiff base-type pyrazolone ligands were obtained in high yield. In comparison with their simple 1,3-diketonate analogs, novel ligands have relatively high located triplet energy levels, which fit much more properly with the emissive energy levels of the Tb3+ cation.Figure optionsDownload as PowerPoint slideHighlights
► New tripodal ligands and their luminescent complexes were prepared.
► Increase of the triplet energy level while compared to the initial pyrazolone.
► Increased luminescence for two of 4-benzoyl-pyrazolone Tb(III) complexes.