Design, Assembly And Luminescent Properties Of Novel Rare Earth Carboxylate Complexes

The study of rare earth organic complexes luminescence, being the cross science of inorganic materials luminescence, organic materials luminescence and noctilucence, is of great importance for fundamental and applied research. Rare earth organic luminescent complexes have become excellent luminescent materials due to the particular electronic structure of lanthanide ions, and they have potential applications in the fields of laser, photoluminescence and electroluminescence. In this paper, 16 rare earth and 2 transition metal carboxylate complexes were prepared, with the first ligands o-bromobenzoic acid (HBBA), diglycolic acid (H2dga), tetrafluorosuccinic acid (H2tfsa), hexafluoroglutaric acid (H2hfga) and the neutral ligands 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy), and structurally characterized by single-crystal X-ray diffraction, and also characterized by elemental analysis, TG-DTA, IR, UV-Visible and fluorescence spectroscopies.1. The current research status and potential applications of the luminescent rare earth orga- -nic carboxylate complexes were discussed.2. Three europium(Ⅲ) complexes {Eu(BBA)3·H2O}n (2-1), [{Eu2(BBA)6(bipy)2}2·H2O·CH3CH2OH] (2-2) and [Eu2(BBA)4(bipy)2(CH3COO)2] (2-3) were prepared with HBBA ligands. In complex 2-1, the Eu3+ ions are linked together by carboxyl groups of BBA ligands in tetradentate-bridging mode to form an infinite one-dimensional chain polymeric structure, which is rare in lanthanide carboxylate complexes; there are two unique dinuclear units in the molecule of complex 2-2, which is also rare in lanthanide carboxylate complexes; and the complex 2-3 is a quaternary dinuclear molecule. The three complexes above all exhibit great characteristic emission of Eu3+ ions.3. A binary Coordination Polymer {[Dy2(dga)3(H2O)4]·2H2O}n (3-1) was prepared with H2dga ligand under hydrothermal condition. The polymer possesses two different types of Dy3+ ions, and the carboxyl oxygen and the ether oxygen atoms coordinate to the Dy3+ ion simultaneously to form a two-dimensional network structure. The polymer exhibits great characteristic emission of Dy3+ ion.4. A series of flexible polycarboxylate coordination polymers [Eu2(tfsa)3(phen)2]n (4-1), [Tb(tfsa)1.5(phen)2(H2O)]n (4-2), {[Sm(tfsa)(phen)(H2O)4]·0.5(tfsa)·2(phen)·H2O}n (4-3), {[Dy (tfsa)(phen)(H2O)4]·0.5(tfsa)·2(phen)·H2O}n (4-4) and [Nd2(tfsa)3(phen) 2]n (4-5) were prepared with H2tfsa and phen under hydrothermal condition for the first time. Complexes 4-1 and 4-2 possess two-dimensional network structure with (4,4) and (6,3) topology, respectively. Com plexes 4-3 and 4-4 are isostructural, and they possess rare one-dimensional chain polymeric structure, in which the center metal ions are bridged by polycarboxylate ligands. Complex 4-5 hold a two-dimensional network structure with (4,4) topology as well as 4-1. The five polymers above all exhibit great characteristic emission of rare earth ions.5. Two ternary terbium(Ⅲ) and europium(Ⅲ) complexes [Tb2(hfga)2(phen)4(H2O)6]·hfga ·2H2O (5-1) and [Eu2(hfga)2(phen)4(H2O)6]·hfga·2H2O (5-2) were prepared with H2hfga and phen by hydrothermal method for the first time. The two complexes are isostructural, and they hold rare dinuclear structures, in which the center metal ions are bridged by double polycarboxylate ligands. The hydrogen bond interactions between free hfga ligand, lattice H2O and dinuclear units lead to a two-dimensional network structure. The two complexs above all exhibit great characteristic emission of rare earth ions.6. Other works: two lead(Ⅱ) coordination polymers with H2tfsa, H2hfga and phen were prepared. One complex [Pb(tfsa)(phen)]n (6-1) of which was structurally characterized by X-ray diffractometry, and it posesses a two-dimensional network structure.