Synthesis, Characterization, and Photoluminescent Properties of Novel Europium Complexes: Effect of the Ligand Structure on the Emission Quantum Yield

چکیده مقاله

The unique photoluminescent properties of europium complexes with organic ligands render them appropriate for a host of applications, such as display devices, lighting, and sensor applications. However, Weak absorption transitions of Eu3+ ion mandates the use of antenna molecules for indirect excitation of the metal center. In most cases, the luminescent complexes consist of a central europium ion and chelating organic ligand as a photosensitizer. The use of organic ligands in europium complexes increased the luminescence intensity from the lanthanide ion. The ligand must have suitable excited states to transfer energy to the Eu3+ ion. New europium(III) complexes of the general formula Eu(tta)3(L) [where L = 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-phenyl-1,3,5-triazine (L1), 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-(4-methoxyphenyl)-1,3,5-triazine (L2), 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-(naphthalen-1-yl)-1,3,5-triazine (L3), or 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-(naphthalen-1-yl)-1,3,5-triazine (L4)] were synthesized and characterized by elemental analysis, FT-IR, 1H NMR, mass spectrometry, X-ray crystallography, and photoluminescence (PL) spectroscopy.