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A novel bimetallic 4f-3d metal-isonicotinic acid inorganic-organic hybrid complex [{Eu(NC5H4COOH)3(H2O)2}(1.5ZnCl4)·(2H2O)]n (1) was synthesized via a hydrothermal reaction and structurally characterized by single- crystal X-ray diffraction. Complex 1 crystallizes in the space group C2/c of the monoclinic system with eight formula units in a cell: a = 23.878(8) Å, b = 20.573(6) Å, c = 15.358(5) Å, β = 127.276(5)°, V = 6003(3) Å3, C18H23Cl6EuN3O10Zn1.5, Mr = 904.11 g/mol, ñ = 2.001 g/cm3, S = 1.077, μ(MoKα) = 3.846 mm-1, F(000) = 3536, R = 0.0270 and wR = 0.0672. Complex 1 has a characteristic, one-dimensional polycationic chain-like structure. A photoluminescent investigation revealed that the title complex displays intense emissions in the orange and red regions. The luminescence spectra show that the red emission is stronger than the orange emission. Optical absorption spectra of 1 revealed the presence of an optical gap of 3.56 eV.

A new lanthanide compound [Gd(2,5-HPA)(2,5-PA)]n (1; 2,5-H2PA = 2,5-pyridinedicarboxylic acid) was obtained through hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction. It possesses a three-dimensional (3-D) framework structure. Solid-state photoluminescence experiment revealed that it shows dark blue emission band, which can be assigned to the characteristic emission of the 4f electron intrashell transition of 6P7/2 → 8S7/2 (Gd3+). The energy transfer mechanism was explained by an energy level diagram of the gadolinium ion and 2,5-pyridinedicarboxylic acid ligand. It displayed remarkable CIE chromaticity coordinates of 0.1346 and 0.0678. The solid-state UV/Vis diffuse reflectance spectra unveiled that it possesses a wide optical band gap of 3.52 eV. Thermogravimetry (TG) measurements revealed that this compound is highly thermal stable up to around 500 °C. [ABSTRACT FROM AUTHOR]

A novel open-framework cadmium selenite bromide, [Cd10(SeO3)8Br4]·HBr·H2O (1), has been obtained by a solid-state reaction at 450°C, and the structure has been determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in Pbcm of the orthorhombic system: a=10.882(3), b=16.275(5), c=18.728(6)Å, V=3317(2)Å3, R1/wR2=0.0411/0.0659. Compound 1 is characteristic of a novel 3-D open-framework structure, composing ∞ 2[CdSeO3] layers and the pillars of edge-shared CdO3Br2 square pyramids. The lattice water molecules and the HBr molecules locate in the voids of the framework. Optical absorption spectrum of 1 reveals the presence of an optical gap of 1.65eV. Solid-state photoluminescent study indicates that compound 1 exhibits strong violet emission. TG–DSC measurement shows that compound 1 is thermally stable up to 200°C. [ABSTRACT FROM AUTHOR]

Abstract: Two novel metal sulfur chlorides – Zn6S5Cl2 (1) and Hg3ZnS2Cl4 (2) – were obtained by solid-state reactions and structurally characterized by single-crystal X-ray diffraction. Compound 1 is characteristic of a 1-D tunnel-like structure, which connects to each other to construct a 3-D framework with the chlorine atoms locating at the voids. Compound 2 crystallizes in the acentric space group P63 mc of the hexagonal system. Compound 2 features a 2-D layered motif, which is composed by the interconnected 12-membered Hg6S3Cl3 rings with chair-like conformation. There are ZnSCl3 tetrahedra located between the layers, yielding a sandwich-like structure. TG-DTA measurement shows that compound 1 is thermally stable up to 220°C. Optical absorption spectra reveal the presence of sharp optical gap of 2.71 and 2.65eV for 1 and 2, respectively. [ABSTRACT FROM AUTHOR]

Two novel lanthanide mercury materials, [Gd(IA)3(H3O)2Hg3Br6]n·2nCl (1) and [La(IA)3(H3O)2Hg3Br6]n·2nCl (2) (IA = isonicotinic anion), have been prepared under solvothermal conditions and characterized by single-crystal X-ray diffraction techniques. They are isomorphic and characterized by a three-dimensional (3-D) framework structure. The lanthanide ions are bound by eight oxygen atoms to exhibit a square antiprismatic geometry. The solid-state photoluminescence experiment discovers that compound 1 shows a strong emission in the red region. Compound 1 possesses CIE (Commission Internationale de I'Éclairage) chromaticity coordinates of 0.7347 and 0.2653. Its CCT (correlated color temperature) is 6514 K. Compound 2 displays yellow photoluminescence and it has CIE chromaticity coordinates of 0.4411 and 0.5151. The CCT of compound 2 is 3633 K. Solid-state UV/Vis diffuse reflectance spectra revealed that their semiconductor band gaps are 2.16 eV and 2.85 eV, respectively.

A novel terbium-containing fluorescent material, [Tb(CH3COO)2(H2O)3]Cl (1), has been prepared by a facile approach, i.e. an ultrasonic synthesis. Compound 1 has been structurally characterized via single-crystal X-ray diffraction and it crystallizes in the space group P21/n of the monoclinic system with four formula units in a cell. Compound 1 features a novel one-dimensional (1-D) chain-like structure. The 1-D chains are interconnected by hydrogen bonds to yield a 3-D supramolecular framework. Photoluminescent investigation reveals that compound 1 displays strong emission bands identified as the characteristic emissions of 5D4 → 7FJ (J = 3, 4, 5, 6) of Tb3+.