Synthesis and fluorescent properties in complexes of Eu(III), Tb(III), and Sm(III) with β-diketone and 2,2′-bipyridine

Three new rare earth ternary complexes, RE（PB）₃bpy (RE=Sm³⁺ , Eu³⁺ , and Tb³⁺ ), were synthesized by the reaction of 1-（p-phenylethynyl- phenyl）-1,3-butanedione （HPB） and 2,2′-bipyridine （bpy） with rare earth chloride RECl₃ , respectively, in alcohol solution. The compositions were characterized by means of infrared （IR） spectra, chemical analysis, elemental analysis, and thermodynamic analysis. Luminescent properties of the three complexes were studied. At room temperature, under UV light excitation, the Sm³⁺ , Eu³⁺ , and Tb³⁺ complexes exhibit characteristic emission of the central ions. The fluorescence spectra show that the fluorescence emission intensity of Eu³⁺ complex is the strongest. The narrow strongest emission band of Eu³⁺ complex is considered to be a valuable material with bright red fluorescence.