Topology and Photoluminescence Property of a Neodymium-carboxylate Coordination Polymer Based on a Tripodal Flexible Ligand

A new metal-organic coordination polymer {[Nd（tci）（H2O）2]·2H2O}n（1） has been synthesized based on the flexible tricarboxylate ligand tris（2-carboxyethyl）isocyanuric acid（H3tci） and structurally characterized by single-crystal X-ray diffraction analyses, elemental analysis, infrared spectra（IR）, powder X-ray diffraction（PXRD） and thermogravimetric analysis（TGA）. Complex 1 crystallizes in triclinic, space group P1 with a = 9.1648（11）, b = 9.3326（12）, c = 12.440（2） , C（12）H（20）N3O（13） Nd, Mr = 558.55, V = 886.9（2） 3, Z = 2, Dc = 2.092 g·cm-3, μ = 3.006 mm-1, F（000） = 554, 2.56〈θ〈25.00°, λ（Mo Kα） = 0.71073 , T = 293（2） K, the final R = 0.0662 and w R = 0.2071. X-ray diffraction analysis reveals that complex 1 is a two-dimensional layer, which is further assembled into a three-dimensional supramolecular architecture through hydrogen bonding interactions. The structure of complex 1 can be simplified as a rare 2-periodic uninodal {48·62} topology and a non-interpenetrating kgd topology. Furthermore, the thermal stability and photoluminescence property of 1 were investigated.

Synthesis,Crystal Structure and Photoluminescence Property of a Ni(Ⅱ) Coordination Polymer with One-dimensional Double-sinusoidal Structure

A new coordination polymer [Ni（3-bpo）（m-bdc）（C2H5OH） 2]n（1,3-bpo = 2,5-bis（3-pyridyl） -1,3,4-oxadiazole,m-H2bdc = 1,3-benzenedicarboxylic acid） was solvothermally synthesi-zed and characterized by IR,TGA and single-crystal X-ray diffraction. The title complex crystalli-zes in the orthorhombic system,space group Pnma with a = 7.786（3） ,b = 17.253（6） ,c = 18.478（6） ,V = 2481.9（14） A^3,Mr = 539.18,Dc = 1.443 g/cm^3,Z = 4,R = 0.0353 and wR = 0.0589. The m-bdc and 3-bpo bridge two Ni（Ⅱ） ions through two carboxylate groups and two pyridyl groups forming a 1D infinite double-sinusoidal chain along the c axis. The photoluminescence of 1 shows a large red shift compared to that of free ligands in the solid state.

Solvothermal Synthesis,Crystal Structure and Photoluminescence Property of a 3D Lead(Ⅱ)Coordination Polymer Based on Terephthalic Acid

Solvothermal reaction of Pb（NO3）2·6H2O with rigid linear ligand terephthalic acid（H2pta） in N,N-dimethylformamide（DMF） produced a new three-dimensional（3D） lead（Ⅱ）coordination polymer[Pb2（pta）1.5（μ4-OH）（DMF）]n 1,and its structure was characterized by single-crystal X-ray diffraction analyses.In polymer 1,the μ4-OH bridges the nearby lead（Ⅱ） ions into an infinite one-dimensional（1D） chain,and then the organic ligand pta^2- joins the neighbored chains into a 3D structure by two similar connection modes in different configurations.The solid-state photoluminescent studies revealed that 1 exhibits a strong greenish emission mainly originating from ligand-to-metal charge transfer between the delocalized π bonds of the aromatic carboxylate ligand pta^2- and the p orbitals of the Pb^2＋ centers.

A Cd(Ⅱ) Coordination Polymer Containing 4-(1-H-imidazol-2-yl) Benzoic Acid Ligand: Synthesis, Crystal Structure, and Photoluminescence Property

A new cadmium（II） polymer based on imidazole derivative, formulated as [Cd（Hiba）2]n 1, H2iba = 4-（1-H-imidazol-2-yl） benzoic acid）, has been synthesized under hydro- thermal conditions. The compound crystallizes in triclinic system, space group P1 with a = 7.062（4）, b = 10.840（7）, c = 13.099（8） A, a = 98.102（7）, fl = 101.524（7）, y = I07.961（7）°, V= 912.3（10） A3, Z = 2, Mr = 486.75, Dc = 1.772 Mg/m3,/t = 1.234 mm-1, F（000） = 484, the final R = 0.0735 and wR = 0.1739 for 2154 observed reflections with 1 〉 20（I）. Polymer 1 consists of （Cd-Hiba）2 zigzag chains, which are further linked by hydrogen bonding to extend into a two-dimensional （2D） corrugated-shape sheet structure. The 2D structures are further connected into a 3D supramolecular edifice through hydrogen bonding. The polymer exhibits exceptional high thermal stability. The bulk purity of the materials of 1 was confirmed through the powder X-ray diffraction （PXRD） patterns. The luminescent property of polymer I has also been investigated.

A New Cd(Ⅱ)Coordination Compound Based on 4-(1,2,4-Triazol-4-yl)phenylacetic Acid:Synthesis,Structure and Photoluminescence Property

A new complex [Cd2（L）2（Cl）2（H2O）]n（1） was synthesized by reacting CdCl2·2.5 H2O with 4-（1,2,4-triazol-4-yl）phenylacetic acid（HL） ligand.The structure of the complex was characterized by single-crystal X-ray diffraction,IR spectroscopy,elemental analysis and PXRD.Complex 1 crystallizes in triclinic,space group P21/c with a = 11.4303（8）,b = 14.1792（10）,c = 14.6857（10） ？,β = 96.3780（10）o,V = 2365.4（3） A^3,Z = 4,C（20）H（16）Cl2N6O5Cd2,Mr = 716.09,Dc = 2.011 g/cm3,μ = 2.069 mm^-1,S = 1.051,F（000） = 1392,the final R = 0.0458 and wR = 0.0949 for 5402 observed reflections（I 〉 2σ（I））.Complex 1 is a two-dimensional（2D） layer structure and non-covalent bonding interactions such as C–H···π and π···π extend the 2D to form a three-dimensional supramolecular polymer.

Temperature dependence of photoluminescence property in BaIn_2O_4

The temperature-dependent photoluminescence （PL） spectra of Baln204, prepared by coprecipitation, are measured and discussed. Aside from the reported 3.02-eV violet emission, the 1.81-eV yellow emission in- volved with oxygen vacancy is also observed at room temperature wherein the deep donor level is at 1.2 eV. With the temperature increasing, the peak energies for both emissions show a red shift. Moreover, the yel- low emission intensity decreases while the violet emission intensity increases. The temperature dependence of the yellow emission intensity fits very well into the one-step quenching process equation, indicating a fitted activation energy at 19.2 meV.

Synthesis,Crystal Structure and Fluorescence Property of the Ag(Ⅰ) Coordination Polymer Constructed by 2D[Ag(1,3-BIP)(PMA)_(0.5)]_n^(n-)Layers and 1D[Ag(1,3-BIP)(H_2O)]_n^(n+) Chains

A new AgO） coordination polymer, {[Ag（1,3-BIP）（H20）][Ag（1,3- BIP）（PMA）0.5.- 4H20}n （PMA = 1,2,4,5-benzenetricarboxylic acid, 1,3-BIP = 1,3-bis（imidazole）propane）, have been synthesized and characterized by single-crystal X-ray diffraction, powder XRD, FTIR, TGA and elemental analysis techniques. The single-crystal X-ray diffraction reveals that the title complex is formed by 1D polymeric cationic chains of [Ag（1,3-BIP）（H2O）]n^n＋ and 2D polymetric anionic layer of [Ag（1,3-BIP）（PMA）0.5]n^n-, which are further linked by intermolecular H-bonding to form a 3D supramolecular framework. In addition, the photoluminescence property of the title complex in the solid state at room temperature was also investigated.

Synthesis, Structure and Photoluminescent Property of an Entangled Cd(Ⅱ) Complex Constructed from a Rigid Imidazolyl Ligand

The assembly of rigid 1, 4-di（1H-imidazol-4-yl）benzene （L） and Cd（OAc）2·2H2O affords an entangled complex [Cd（L）2（OAc）2]n （1） which was characterized by single-crystal X-ray diffraction, IR, elemental analysis and PXRD. The complex crystallizes in monoclinic, space group P21/c with a = 8.2603（9）, b = 11.8162（13）, c = 14.4138（16）, β = 105.309（2）o, V = 1356.9（3）3, Z = 2, C28H26CdN8O4, Mr = 650.97, Dc = 1.593 g/cm3, μ = 0.856 mm？1, S = 1.015, F（000） = 660, the final R = 0.0456 and wR = 0.1366 for 2532 observed reflections （I 2σ（I））. 1 possesses [Cd（L）2]n layer motifs, and parallel sets of layer motifs aggregate into a 2D ＋ 2D → 3D mutually interpenetrated system. Photoluminescence study revealed that complex 1 exhibits strong fluorescent emission bands in the solid state at room temperature.

Syntheses,Crystal Structures and Photoluminescence Properties of Two Cadmium(Ⅱ)Coordination Polymers

The solvothermal reaction of CdCl2·2.5H2O with terephthalic acid yields two new three-dimensional(3D)cadmium(II)coordination polymers(CPs),namely{[Cd(C8H4O4)Cl]·C2H8N}n and[Cd(C8H4O4)]n,we use the abbreviations CP1 and CP2 to refer to them,respectively.The compounds are characterized in detail by single-crystal X-ray diffraction,powder X-ray diffraction,IR spectroscopy,elemental analysis and thermogravimetric analysis(TGA).The results indicate that compounds CP1 and CP2 are 3D frameworks,and both the compounds feature a uninodal 4-connected framework with a dia net.The empty spaces of such 3D framework are filed by the other two identical frameworks,leading to a 3-fold interpenetrated network.In addition,the photochemical properties of the frameworks are also investigated.The two frameworks show strong solid-state fluorescence emission at 463 and 503 nm,respectively,which are obvious red-shift compared to the emission of ligand.

Synthesis,Structure and Photoluminescent Property of a Cd-organic Complex [Cd(L)_2(pbda)]_n

A new complex,[Cd（L）2（pbda）]n（1,L = 3-（2-pyridyl）-4-（p-methoxyphenyl）-5-（2-thienyl）-1,2,4-triazole,H2pbda = 1,4-benzenedicarboxylic acid）,has been hydrothermally prepared and characterized by single-crystal X-ray diffraction,IR spectroscopy,elemental analysis and PXRD.The complex crystallizes in monoclinic,space group P21/c with a = 8.2929（9）,b = 21.668（2）,c = 10.9940（11） ,β = 90.242（2）o,V = 1975.5（4） 3,Z = 2,C44H32N8O6S2Cd,Mr = 945.30,Dc = 1.589 g/cm3,μ = 0.721 mm-1,S = 1.097,F（000） = 960,the final R = 0.0590 and wR = 0.1045 for 3846 observed reflections（I 2σ（I））.In the title complex,the rigid bridging pbda2-ligands utilize oxygen atoms of carboxylate groups to coordinate with Cd（II） atoms to form one-dimensional chains which are further interlinked into a three-dimension framework via the intermolecular weak interactions.Photoluminescence study revealed that complex 1 exhibits strong fluorescent emission band in the solid state at room temperature.

Synthesis, Structure and Photoluminescent Property of a New 3D Cd(Ⅱ) Coordination Polymer with Terphenyl-2,2',4,4'-tetracarboxylic Acid and 1,10-Phenanthroline

A new 3D Cd（II） coordination polymer, [Cd2L（phen）（HzO）]n （1, HaL = terphenyl- 2,2＇,4,4＇-tetracarboxylic acid, phen = 1,10-phenanthroline）, has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, TGA and IR spectroscopy. Complex 1 crystallizes in the monoclinic system, space group P21/c with a = 8.196（2）, b = 18.348（5）, c = 19.036（5） A, β = 97.741（5）°, V= 2836.6（14） A3, Z = 4, Dc = 1.933 Mg.m-3, p = 1.565 mm1, F（000） = 1624, the final R = 0.0356 and wR = 0.0612 for 4990 observed reflections with 1 〉 2a（I）. Complex 1 has a 1D chain containing Cd4 structural units, which are linked by 2- and 2＇-carboxyl groups of L4- to result in a 3D framework. Additionally, the photoluminescent property of 1 was also studied in the solid state at room temperature.

Fluorescence Quenching of a Novel Eu(Ⅲ) Coordination Compound for the Detection of Trace Amounts of Water： Synthesis, Structure and Photoluminescent Property

A novel luminescent coordination compound Eu（TTA）3（DEDAF）（1, TTA = 1,1,1-trifluoro-3-（2-thenoyl）acetone, DEDAF = 9,9-diethyl-4,5-diazafluoren） has been synthesized and fully characterized by infrared spectrum, elemental analysis, UV-vis spectrum, etc. X-ray single-crystal diffraction analysis reveals that compound 1 shows a mononuclear structure with the europium atom in coordinating to one DAF and three TTA ligands. The mononuclear structure units are assembled into a 3-D polymer by hydrogen bonds and π-π interactions. Photoluminescent property of 1 was investigated in detail at room temperature. Complex 1 emits strong red luminescence. However, it could be quenched even by small amount of water. The fluorescence intensity at 614 nm decreases linearly with the water content increasing（vol% in acetonitrile） in the range of 0.025~0.2% under 278 nm excitation. Thermogravimetric analysis has also been studied, which demonstrates good thermal stability of 1.

Synthesis and Photoluminescence of New Europium Complex Eu(DBM)_3(DPPZ) with Dipyridophenazine Ligand

Dipyrido [3, 2-a:2,3-c] phenazine moiety has been introduced as neutral ligand in europium complex. Therefore, a new europium complex with saturated emission, strong fluorescent intensity and good solubility was designed and synthesized for the first time. Its photoluminescence and UV properties were examined. The experimental results showed that this new Eu-complex could be used as red electroluminescent materials.

Synthesis, Crystal Structure and Photoluminescent Property of a Novel Disilver Complex with Pyrazinyl Oxime Ligand

A novel binuclear Ag（I） complex [Ag2（C6H6NaO）2（C6H7N3O）2]·2CH3CN （1） was synthesized by the evaporation reaction of silver nitrate and （E）-1-（pyrazin-2-yl）ethanone oxime （HL）. The complex was characterized by elemental analysis, IR spectrum and X-ray single-crystal diffraction analysis. It crystallizes in the monoclinic space group C2/c with a = 22.7089（3）, b = 11.5443（7）, c = 16.1468（4）/A, β = 127.7150（10）°, V= 3348.6（2） A^3, Dc = 1.675 g/cm^3, Mr = 844.42, Z = 4, F（000） = 1696.0,μ = 1.226 mm^-1, the final R =0.0250 and wR = 0.070. The coordination around the silver（I） atom is a distorted trigonal-bipyramidal geometry involving one protonated pyrazinyl oxime ligand （HL）, one deprotonated oxime ligand （L^-） and one CH3CN solvate molecule in the asymmetric unit of complex 1.

Synthesis,Structure,Photoluminescence and Photocatalytic Properties of a New Cd(Ⅱ)Metal-organic Framework Based on 1,4-Di(2,6-dimethyl-3,5-dicarboxypyridyl)benzene

A new 3D coordination polymer, [Cd2（L）（bpb）2]n（1, H4L = 1,4-di（2,6-dimethyl-3,5-dicarboxypyridyl） benzene, bpb = 1,4-bis（4-pyridyl） benzene, has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, TGA, IR spectroscopy and UV-Vis spectrum. Complex 1 crystallizes in orthorhombic, space group C2221, with a = 10.9393（12）, b = 20.900（3）, c = 20.027（2） A, β = 90°, V = 4578.9（9） A^3, Dc = 41.668 Mg/cm^3, Mr = 1149.74, F（000） = 2312.0, μ = 0.996 mm^（–1）, Z = 4, the final R = 0.0316 and wR = 0.0786 for 4271 observed reflections with I 〉 2σ（I）. Structural analysis shows that 1 possesses a 3D network based on the 2D layer bridged by L^4-ligands, while the 2D layers are composed of the adjacent 1D chains joined by L^4-ligand. The photoluminescent investigation indicates that one broad emission band with the maximum of 445 nm can be observed in 1. Moreover, compound 1 has high photocatalytic degradation effects on methylene blue under UV irradiation.

Synthesis,Structure and Photoluminescent Property of a New 2D Zn(Ⅱ) Coordination Polymer Constructed by Biphenyl-3,3',5,5'-tetracarboxylate

A new 2D Zn（II） coordination polymer,[Zn（btc）0.5（phen）]n（1,H4btc = biphenyl-3,3＇,5,5＇-tetracarboxylic acid,phen = 1,10-phenanthroline）,has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis,elemental analysis and IR spectro-scopy.Complex 1 crystallizes in the triclinic system,space group P1 with a = 7.6878（6）,b = 10.3453（8）,c = 10.9589（9） ,α = 113.3540（10）,β = 90.5460（10）,γ = 90.4280（10）°,V = 800.09（11） 3,Z = 2,Dc = 1.696 Mg.m-3,μ = 1.566 mm-1,F（000） = 414,the final R = 0.0359 and wR = 0.0778 for 2441 observed reflections with I 2σ（I）.Complex 1 has a 2D layered network containing dinuclear Zn（II） structural units.The 2D layers are further linked by the phen molecules through π-π stacking interactions into a 3D supramolecular framework.The photoluminescent property of 1 was also studied in the solid state at room temperature.

Influence of Al^(3+) doping on the energy levels and thermal property of the 3.5MgO·0.5MgF_2·GeO_2:Mn^(4+) red-emitting phosphor

A series of Al3+-doped 3.5MgO·0.5MgF2·GeO2:Mn4+red-emitting phosphors is synthesized by high temperature solid-state reaction. The broad excitation band at 300 nm–380 nm, resulting from the4A2→4T1transition of Mn4+,exhibits a blue shift with the increase of Al2O3 content. The observation of the decreased Mn4+–O2-distance is explained by the crystal field theory. The temperature-dependent photoluminescence spectra with various amounts of Al2O3 content are comparatively measured and the calculation shows that the activation energy increases up to 0.41 eV at the Al2O3 content of 0.1 mol. The maximum phonon densities of state for these samples are calculated from Raman spectra and they are correlated with the thermal properties.

Study of Shifted UV Emission Peak of ZnO Nanowire Arrays

We have obtained vertically aligned ZnO nanowire arrays synthesized by microwave-assisted heating method with different growth time.From the room-temperature PL measurement,the strong deep-level emission and weak near band edge(NBE)emission can be seen.The deep-level emissions became weaker and deep-level emissions became stronger when the samples were annealed at 300℃for 30 min,meanwhile,the NBE emission peaks get red-shifted with growth time,and the longer the growth time,the more the peak shifting.This phenomenon can be attributed that the diameter of ZnO nanowires increases with growth time.This PL emission phenomenon is important in research of optoelectronic application.

Preparation and Dielectric Properties of Nanostructured ZnO Whiskers

By a novel controlled combustion synthesis method, a large number of nanostructured ZnO whiskers with different morphologies, such as tetra-needles, long-leg tetra-needles and multi-needles, are prepared without any additive in open air at high temperature. The morphologies and crystalline structures of the as-prepared ZnO nanostructured whiskers are investigated by SEM and XRD. The possible growth mechanism on the nanostructured ZnO whiskers is proposed. The experimental results indicate that the dielectric constants and losses of the nanostructured ZnO whiskers are very low, demonstrating that the nanostructured ZnO whiskers are low-loss materials for microwave absorption in X-band. However, obvious microwave absorption in nanostructured ZnO whiskers is observed. The quasi-microantenna model may be attributed to the microwave absorption of the ZnO whiskers.

Controlled Self-assembly of Two Coordination Polymers via subtly Varying Bis(2-methyl imidazole) Ligands:from 3-Connected(6,3) Net to 4-Connected sql Net

Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis（2-methyl imidazole） ligands, namely, {[Cd2（tdc）2（bip）2]·7H20}n （1） and [Cd（tdc）（bib）]n （2） （Hgtdc = 3,4-thiophenedicarboxylic acid, bip = 1,3-bis-（imidazol-2-methyl）propane and bib = 1,4-bis（imidazol-2-methyl）butane）, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analyses reveal that 1 exhibits a two-dimensional （2D） layered network with 3-connected （6,3） topology, which is further connected into a three- dimensional （3D） supramolecular structure by intermolecular hydrogen bonds. However, 2 features a 2D network which can be rationalized as a 4-connected sql net. The results indicate the subtle difference of auxiliary bis（imidazol-2-methyl） ligands may lead to diverse architectures. Moreover, they exhibit luminescence emission in the solid state at room temperature.