Synthesis, structure and luminescent properties of yttrium benzene dicarboxylates with one- and three-dimensional structure

Bis(2,2'-bipyridyl-κN,N')(carbonato-κO,O')cobalt(III) bromide trihydrate

The title complex, [Co(CO(3))(C(10)H(8)N(2))(2)]Br·3H(2)O, is isostructural with the chloride analogue. The six-coordinated octahedral [Co(2,2'-bipy)(2)CO(3)](+) cation (2,2'-bipy is 2,2'-bipyrid-yl), bromide ion and water mol-ecules are linked together via O-H⋯Br and O-H⋯O hydrogen bonds, generating a one-dimensional chain.

Synthesis, Structure, and Luminescent and Magnetic Properties of Novel Lanthanide Metal−Organic Frameworks with Zeolite-like Topology

A series of microporous lanthanide metal-organic frameworks [Ln(BTC)(DMF)(2) x H(2)O, Ln = Tb (1), Dy (2), Ho (3), Er (4), Tm (5), Yb (6); DMF = N,N'-dimethylformamide] with 4 x 4 x 4 x 6 x 6 x 8 topology, which is very common in the zeolite topologies, have been synthesized under mild conditions. The single-crystal X-ray diffraction analysis reveals that they exhibit the same three-dimensional (3D) architecture and crystallize in monoclinic symmetry space group C2/c. Organic and inorganic four-connected nodes link each other to form a 3D open framework. The framework contains approximate 13 Angstrom x 7 Angstrom rectangle channels along the [1,1,0] and [1,-1,0] directions, respectively. The luminescent properties of these complexes have been studied, and complex 1 shows a Tb(3+) characteristic emission in the range of 450-650 nm at room temperature. Complexes 1-5 exhibit antiferromagnetic interaction between Ln(3+) ions. The water sorption isotherm shows that about 15 water molecules per unit cell can be adsorbed into the micropores of dehydrated complex 4.

Syntheses and Characterization of Six Coordination Polymers of Zinc(II) and Cobalt(II) with 1,3,5-Benzenetricarboxylate Anion and Bis(imidazole) Ligands

Six new coordination polymers, namely [Zn1.5(BTC)(L1)(H2O)2].1.5H2O (1), [Zn3(BTC)2(L2)3] (2), [Zn3(BTC)2(L3)1.5(H2O)].H2O (3), [Co6(BTC)4(L1)6(H2O)3].9H2O (4), [Co1.5(BTC)(L2)1.5].0.25H2O (5), and [Co4(BTC)2(L3)2(OH)2(H2O)].4.5H2O (6), where L1 = 1,2-bis(imidazol-1-ylmethyl)benzene, L2 = 1,3-bis(imidazol-1-ylmethyl)benzene, L3 = 1,1'-(1,4-butanediyl)bis(imidazole), and BTC = 1,3,5-benzenetricarboxylate anion, were synthesized under hydrothermal conditions. In 1-6, each of L1-L3 serves as a bidentate bridging ligand. In 1, BTC anions act as tridentate ligands, and compound 1 shows a 2D polymeric structure which consists of 2-fold interpenetrating (6, 3) networks. In compound 2, BTC anions coordinate to zinc cations as tridentate ligands to form a net with (64.82)2(86)(62.8)2 topology. In compound 3, BTC anions act as tetradentate ligands and coordinate to zinc cations to form a net with (4.62.83)2(8.102)(4.6.83.10)2 topology. In compound 5, each BTC anion coordinates to three Co cations, and the framework of 5 can be simplified as (64.82)2(62.82.102)(63)2 topology. For 4 and 6, the 2D cobalt-BTC layers are linked by bis(imidazole) ligands to form 3D frameworks. In 6, the Co centers are connected by micro3-OH and carboxylate O atoms to form two kinds of cobalt-oxygen clusters. Thermogravimetric analyses (TGA) for these compounds are discussed. The luminescent properties for 1-3 and magnetic properties for 4-6 are also discussed in detail.

A New Series of Three-Dimensional Metal−Organic Framework, [M2(H2O)][C5N1H3(COO)2]3·2H2O, M = La, Pr, and Nd: Synthesis, Structure, and Properties

A new series of lanthanide pyridine dicarboxylates of the general formula, [M2(H2O)][C5N1H3(COO)2]3.2H2O, M = La (1), Pr (2), and Nd (3), has been prepared by the reaction of trivalent lanthanide salts and pyridine dicarboxylic acids employing a mild condition hydrothermal reaction. The structures are built up from MO8N and MO7N2 (M = lanthanide) polyhedra connected to the dicarboxylate anions forming the three-dimensional structure with one-dimensional channels. A striking feature of this structure is the presence of an unusual Z-shaped tetramer of the formula M4O24N6. Extraframework water molecules, located within the open channels, are reversibly adsorbed. Detailed in situ and ex situ investigations using FTIR and PXRD studies clearly show that the removal of the water molecules is reversible and accompanied by changes in the size of the channel. Partial substitution at the La sites by Eu gives rise to characteristic red-pink luminescence, indicating a ligand-sensitized metal-centered emission.

Synthesis, structure and optical properties of rare-earth benzene carboxylates

Two series of rare-earth isophthalates of the general formula, [M(2)(H(2)O)][{C(6)H(4)(COO)(2)}(2){C(6)H(4)(COOH)(COO)}(2)].H(2)O, M=La (I), Pr (Ia), and Nd (Ib) and [M(2)(H(2)O)(2)][{C(6)H(4)(COO)(2)}(3)].H(2)O, M=Y (II), Gd (IIa), and Dy (IIb) have been prepared by the reaction of the corresponding trivalent lanthanide salts and isophthalic acid under mild hydrothermal conditions. The La (I), Pr (Ia) and Nd (Ib) have MO(9) polyhedra connected to the isophthalate anions forming a two-dimensional structure, whereas Y (II), Gd (IIa) and Dy (IIb) have MO(7) and MO(8) polyhedral units connected to the isophthalate anions forming a different, but related two-dimensional structure. Both the structures are stabilized by hydrogen bonding and pi...pi/CH...pi interactions. Partial substitution of Eu and Tb (2 and 4%) at the La (I) and Y (II) sites give rise to characteristic red/pink or green luminescence, indicating a ligand-sensitized metal-centered emission. The Nd (Ib) compound shows interesting UV and blue emission through an up-conversion process.

Novel Photocatalysts for the Decomposition of Organic Dyes Based on Metal-Organic Framework Compounds

Three novel metal-organic frameworks (MOFs) [Co(2)(C(10)H(8)N(2))][C(12)H(8)O(COO)(2)](2), 1, [Ni(2)(C(10)H(8)N(2))(2)][C(12)H(8)O(COO)(2)](2).H(2)O, 2, and [Zn(2)(C(10)H(8)N(2))][C(12)H(8)O(COO)(2)](2), 3, with three-dimensional structures have been synthesized and characterized. The structures of the three compounds appear somewhat related, formed by the connectivity involving the metal polyhedra (Co(4)N trigonal bipyramids in 1, NiO(4)N(2) octahedra in 2, and ZnO(4) tetrahedra and ZnO(3)N(2) trigonal bipyramids in 3), 4,4'-oxybis(benzoate), and 4,4'-bipyridine. The photocatalytic studies on 1-3 indicate that they are active catalysts for the degradation of orange G, rhodamine B, Remazol Brilliant Blue R and methylene blue. The compounds have also been characterized by powder X-ray diffraction, IR, thermogravitmetric analysis, UV-vis, photoluminescence, and magnetic studies.

Rare Earth Coordination Polymers with Zeolite Topology Constructed from 4-Connected Building Units

A series of rare earth coordination polymers, M(BTC)(DMF)(DMSO) (M = Tb (1), Ho (2), Er (3), Yb (4), Y (5)), with zeolite ABW topology have been synthesized under mild conditions. They exhibit the same three-dimensional (3D) architecture and crystallize in monoclinic symmetry space group P2(1)/n. Their structures are built up from inorganic and organic 4-connected building units, whose vertex symbols are 4.4.6.6.6.8. The building units link to each other to generate approximate 5 x 8 angstroms2 channels along the [100] direction. The luminescent and magnetic properties of these compounds are investigated, and the results reveal that they could be anticipated to be potential antiferromagnetic and fluorescent materials.

Synthesis, Structure, and Luminescent Properties of Microporous Lanthanide Metal−Organic Frameworks with Inorganic Rod-Shaped Building Units

A series of microporous lanthanide metal-organic frameworks, Tb3(BDC)(4.5)(DMF)2(H2O)3.(DMF)(H2O) (1) and Ln3(BDC)(4.5)(DMF)2(H2O)3.(DMF)(C2H5OH)(0.5)(H2O)(0.5) [Ln = Dy (2), Ho (3), Er (4)], have been synthesized by the reaction of the lanthanide metal ion (Ln3+) with 1,4-benzenedicarboxylic acid and triethylenetetramine in a mixed solution of N,N'-dimethylformamide (DMF), water, and C(2)H(5)OH. X-ray diffraction analyses reveal that they are extremely similar in structure and crystallized in triclinic space group P. An edge-sharing metallic dimer and 4 metallic monomers assemble with 18 carboxylate groups to form discrete inorganic rod-shaped building units [Ln6(CO2)18], which link to each other through phenyl groups to lead to three-dimensional open frameworks with approximately 4 x 6 A rhombic channels along the [0,-1,1] direction. A water sorption isotherm proves that guest molecules in the framework of complex 1 can be removed to create permanent microporosity and about four water molecules per formula unit can be adsorbed into the micropores. These complexes exhibit blue fluorescence, and complex 1 shows a Tb3+ characteristic emission in the range of 450-650 nm.

Syntheses, Structures, and Luminescent and Magnetic Properties of Novel Three-Dimensional Lanthanide Complexes with 1,3,5-Benzenetriacetate

Five novel lanthanide complexes with the formulas [Nd(bta)(H2O)2.4.35H2O]n(1), [Sm(bta)(H2O)2.4.5H2O]n (2), [Eu(bta)(H2O).1.48H2O]n (3), [Tb(bta)(H2O).1.31H2O]n (4), and [Yb(bta)(H2O).H2O]n (5) (H3bta = 1,3,5-benzenetriacetic acid) have been prepared by using the corresponding lanthanide salt and H3bta. The results of an X-ray crystallographic analysis revealed that all the complexes have three-dimensional channel-like structures, in which the bta3- ligands adopt different coordination modes: monodentate and mu2-eta2:eta1-bridging coordination modes in 1, 2, and 5 and mu2-eta1:eta1-bridging and mu2-eta2:eta1-bridging coordination modes in 3 and 4, respectively. Complexes 1 and 2, as well as 3 and 4, are isostructural, respectively, in which all the Ln(III) (Ln = Nd, Sm, Eu, and Tb) atoms are nine-coordinated, while the Yb(III) atoms in complex 5 are eight-coordinated. Both complexes 3 and 4 showed strong luminescence upon excitation, and their luminescence decay curves fit well with single exponential decays of which the lifetime is 0.45 ms for 3 and 1.0 ms for 4. The magnetic properties of the complexes were investigated in the temperature range of 1.8-300 K.

Synthesis, Structure and Luminescent Properties of Rare Earth Coordination Polymers Constructed from Paddle-Wheel Building Blocks

A series of three-dimensional (3D) novel coordination polymers M(bpdc)1.5(H2O) x 0.5DMF (M = Tb (1), Ho (2), Er (3), or Y (4)) have been synthesized by reaction of the rare earth ions (M3+) with 4,4'-biphenyldicarboxylic acid (H2bpdc) in a mixed solution of DMF and C2H5OH. They possess the same 3D architectures and crystallize in monoclinic space group C2/c. Two seven-coordinated metal centers and four dimonodentate bpdc groups construct a paddle-wheel building block. These building blocks connect with two carboxyl groups to lead to a one-dimensional inorganic chain, ---M-O-C-O-M---, along the [001] direction. The inorganic chains are linked with two biphenyl groups to form 25.15 A x 17.09 A rhombic channels along the c axis without interpenetration. These complexes exhibit strong fluorescence in the visible region, and complex 3 shows Er3+ characteristic emission in the range of 1450-1650 nm at room temperature. These complexes could be anticipated as potential fluorescent probes and an IR-emitter, respectively.