Synthesis, characterization and luminescence property of N,N'-di(pyridine N-oxide-2-yl)pyridine-2,6-dicarboxamide and corresponding lanthanide (III) complexes.
A new ligand, N,N'-di(pyridine N-oxide-2-yl)pyridine-2,6-dicarboxamide (LH2) and its several lanthanide (III) complexes (La, Eu, Gd, Tb, Y) were synthesized and characterized in detail based on elemental analysis, conductivity measurements, IR, 1H NMR, MS (FAB) and UV spectra and TG-DTA studies. The results indicated that the composition of these binary complexes is [Ln(LH2)(NO3)2.H2O]NO3.nH2O (n=0-1); while the ligand has a good planar structure with strong hydrogen bonds. The fluorescence spectra exhibits that the Tb (III) complex and the Eu (III) complex display characteristic metal-centered fluorescence in solid state while ligand fluorescence is completely quenched. However, the Tb (III) complex displays more effective luminescence than the Eu (III) complex, which is attributed to especial effectivity in transferring energy from the lowest triplet energy level of the ligands (T) onto the excited state (5D4) of Tb (III) than that (5D1) of Eu (III).
Zhang
Hai-Jun
HJ
College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, PR China. zhanghaij03@st.lzu.edu.cn
Gou
Ru-Hu
RH
Yan
Lan
L
Yang
Ru-Dong
RD
D000577:Amides / Q000138:chemical synthesis / Q000737:chemistry; D002614:Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry*; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry*; D006860:Hydrogen Bonding; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence
D000577:Amides; D002614:Chelating Agents; D006575:Heterocyclic Compounds, 3-Ring; D028581:Lanthanoid Series Elements; D008024:Ligands