title: [Study on synthesis and fluorescence characterization of europium and terbium complexes of 1-(5-(2-hydroxyphenyl)-3-methyl-4,5-dihydropyrazol-1-yl) ethanone].
abstract: Six solid complexes(TbL3 x 2H2O, TbL2 (phen) x H2O, TbL2 (TPPO), EuL3 x 2H2O, EuL2 (phen) x 2H2O and EuL2 (TPPO) x 2H2O) have been synthesized based on the pyrazole ligand(HL)(phen = 1,10-phenanthroline, TPPO = Tri-phenylphosphine oxide, HL=1-(5-(2-hydroxyphenyl)-3-methyl-4,5-dihydropyrazol-1-yl) ethanone). These complexes were characterized by elemental analysis, IR spectra, and fluorescence spectra. The IR spectra indicated that all complexes exhibited the characteristic peaks of asymmetric stretching vibration v (C=O) and symmetric stretching vibration v (C=N) peaks. The C=O stretching band at 1,644 cm(-1) of HL molecule shifted to lower band in the complexes. The O-H band at 3,072 of the HL ligand is also shifted to lower band. All these shifts indicated that carbonyl group, O-H and C=N take part in coordinating with the rare-earth ion in the form of bridging tridentate. The excitation and emission spectra of the six complexes were determined at room temperature and the results show that EuL2 (Phen) x 2H2O and TbL2 (Phen) X 2H2O display the strongest relative fluorescence intensity with the excited bands at 310 and 320 nm, respectively. Meanwhile, the emission intensities of Eu3+ and Tb3+ complexes were greatly sensitized by phen.
authors.affiliation: College of Chemistry and Ecological Engineering, Guangxi University for Nationalities, Nanning 410006, China. hufeilong1982@163.com
authors.forename: Fei-long
authors.initials: FL
authors.lastname: Hu
authors.forename: Ji-chang
authors.initials: JC
authors.lastname: Zhuang
authors.forename: Xian-hong
authors.initials: XH
authors.lastname: Yin
authors.forename: Qiao-lan
authors.initials: QL
authors.lastname: Wu
authors.forename: Shan-shan
authors.initials: SS
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang