Synthesis, Characterization, and Luminescent Properties of Europium (III) and Terbium(III) Complexes with Bis Piperazine Dithiocarbamate Ligand

In this study, we report the synthesis and comprehensive characterization of europium(III) and terbium(III) chelates incorporating a bis-piperazine dithiocarbamate ligand. These lanthanide complexes were prepared through a straightforward coordination process under mild conditions and characterized using elemental analysis, FT-IR, UV–Vis spectroscopy, thermogravimetric analysis (TGA). Photoluminescence studies revealed strong, characteristic emissions from Eu³⁺ and Tb³⁺ centers, with high quantum yields of 38.7% and 44.2%, respectively. The complexes exhibited long-lived excited-state lifetimes, with decay times of 1.85 ms for Eu³⁺ and 2.23 ms for Tb³⁺. Thermal analysis demonstrated that all complexes remained stable above 250 °C. These findings highlight the significant role of the bis-piperazine dithiocarbamate ligand in enhancing the sensitization and luminescent efficiency of lanthanide centers. Overall, the synthesized complexes show great potential as functional luminescent materials for applications in sensing, optoelectronics, and bioimaging.