Synthesis and luminescent properties of novel pyrazolone rare earth complexes

Abstract A novel pyrazolone pyridine-containing ligand, 2,6-bis(1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl)pyridine ( H 2 L ) was designed and synthesized from pyridine-2,6-dicarboxylic acid ( 1 ), and its Eu(III) and Tb(III) complexes were prepared. The ligand and complexes were characterized in detail based on FT-IR spectra, 1 H NMR, elemental analysis and thermal analysis, and the formula of Ln 2 L 3 ·4H 2 O (Ln=Eu or Tb) of rare earth complexes was confirmed. The UV-vis absorption spectra and photoluminescence properties of the complexes were investigated, which showed that the Eu(III) and Tb(III) ions could be sensitized efficiently by the ligand ( H 2 L ) and emit the photoluminescence with high intensity, narrow half-peak width, and monochromic light. The results indicated that the complexes showed potential as excellent luminescent materials.