Luminescent Properties of Metal Complexes and Metal Polymers of Europium(III) with 2-Methyl-5-phenylpentene-1-dione-3,5

This work presents the synthesis and study of the structure and emission properties of mono- and heteroligand and polymer complexes of europium(III) as EuL₃, EuL₃Phen, [EuL₃]_n, and [Eu(L)₃Phen]_n by using the ligand 2-methyl-5-phenylpentene-1-dione-3,5 (HL) and coligand 1,10-phenanthroline (Phen). To achieve excellent photoluminescent properties, the coligand was introduced into the complexes to form a rigid conjugated system, thus improving the luminescent properties of the complexes. The synthesis and optical properties of the ligand HL are presented. A feature of this ligand is the presence of an unsaturated substituent, which makes compounds based on it active monomers in polymerization reactions. Using physicochemical methods of analysis, the composition, structure, and coordination environment of the central europium ion were determined. It is shown that during polymerization, the coordination environment of the central ion does not change. The study of the luminescent properties of compounds in solution and the solid state and the calculation of the emission parameters indicate the difference in the emission of polymeric and heteroligand complexes compared to their monomeric counterparts. Owing to their strong red luminescence, these complexes might be used in the fabrication of optoelectronic devices.