Synthesis And Luminescence β- Diketone Double Helix Structure Of Rare Earth Complexes In Nature

β-diketone compounds as excellent oxygen-containing ligands, have high lightabsorption coefficients and strong coordination ability to the rare earth ions. It existsefficient energy transfer from the ligand to the central ion (especially Eu3+and Tb3+) inthe complexes, which brings rare earth β-diketone complexes excellent luminescentproperties and a wide range of application in areas such as supramolecule, opticalcommunication amplifiers, sensors, and biological probes.In this work, we have prepared three bis-diketones BTDS, BTM and BBT throughthe coupling of two mono-ketones (BTFA, and TTA) via spacers. And we furthersynthesized23corresponding lanthanide complexes, namely, Ln2(BTDS)3(H2O)4[Ln=Eu (1), Sm (2), Nd (3), Yb (4), Gd (5)]; Ln2(BTDS)3(Phen)2[Ln=Eu (6), Sm (7), Nd (8)Yb (9), Gd (10)),(Phen=1,10-phenanthroline);(HNEt3)2Ln2(BTDS)4[Ln=Eu (11),Sm (12), Nd (13), Yb (14), Gd (15),(HNEt3)2=triethylamine)]; Ln2(BTM)3(H2O)4[Ln=Eu (16), Nd (17), Yb (18), Gd (19)]; Ln2(BBT)3(H2O)4[Ln=Eu (20), Nd (21), Yb(22), Gd (23),].By means of single-crystal diffraction, IR, UV, MS and TG characterization of theabove complexes, we find out that the structure of the complexes are dinuclear triplehelical or quadruple-stranded dinuclear helical. Meanwhile solid or liquid fluorescencespectra, the life decay curves and quantum yields of rare earth (Eu) compounds weremeasured at298K, and the liquid state fluorescence spectra of rare earth (Nd3+, Yb3+)compounds were measured at298K.Based on the study on the luminescence properties of the above complexes, wefind out that dinuclear complexes possess better luminescence properties and morevariety in structure than the mononuclear complexes. Therefore, the study on thestructure and properties of the dinuclear complex will provide valuable theoreticalguidance and experimental data for the development of helicate lanthanide complexes.