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 and photoluminescence properties of Sr4La(PO4)3O： RE3＋ (RE=Eu/Tb/Ce) phosphors

A series of RE3＋ （RE = Eu/Tb/Ce）-activated Sr4La（PO4）3O （SLPO） phosphors are synthesized with a high- temperature solid-state reaction method. The photoluminescence properties, thermal stability, morphology, and CIE values of the SLPO：EuS＋/Tb3＋/Ce3＋ phosphors are investigated. Under 394 nm excitation, the SLPO：Eu3＋ exhibits red emission, and the SLPO：Tb3＋ presents a green emission upon 379 nm excitation, while Ce3＋-doped SLPO has a broad emission band ranging from 370 to 650 nm under 337 nm excitation. The investigation results indicate that the SLPO：Eu3＋/Tb3＋/Ce3＋ phosphors can be effectively excited by near- ultraviolet light and may have the potential to serve as red-, green-, and blue-emitting phosphors for applications in white light-emitting diodes.

Rapid Synthesis and Photoluminescence Properties of Eu-doped ZnO Nanoneedles via Facile Hydrothermal Method

Eu-doped ZnO nanoneedles with different doping concentrations were prepared via the facile hydrothermal method.The crystal structure,morphology and photoluminescence property of the ZnO nanoneedles were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）,photoluminescence spectroscopy（PL） and Raman spectroscopy.The results show that the europium ions are incorporated into the crystal lattice of ZnO matrix in trivalent ions.The nanoneedles are 2-3 μm in length and 100 nm in the tip diameter.PL and Raman measurements indicate that higher Eu^3＋ doping concentration may destroy the crystallization of the nanoneedles and decrease the ratio of IUV/IDLE,which is mainly due to the more defects in the doped ZnO nanoneedles.And the characteristic red emissions of Eu^3＋ ions are found by the PL spectroscopy with the Eu^3＋doping concentration increasing,which are attributed to the ^5D0→^7F0,^5D0→^7F1 and ^5D0→^7F2 transitions.

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.

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.

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.

Syntheses, Structures, and Photoluminescent Properties of Two 2D Coordination Polymers Based on 1,3-Di(2,4-dicarboxyphenyl) Benzene and 1,3-Di(4-pyridyl)propane

Two new 2D coordination polymers, [Zn（HL）（Hbpp）]n （1） mid [Cd（HL）（Hbpp）（H2O）]n （2） （H4L = 1,3-di（2,4-dicarboxyphenyl） benzene, bpp = 1,3-di（4-pyridyl）propane）, have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, TGA and 1R spectroscopy. Complex 1 crystallizes in monoclinic, space group P21/n, with a = 13.1031（6）, b = 14.7315（7）, c = 15.0041（7） A, β = 91.202（1）°, V= 2895.6（2） A3, Dc = 1.532 g/cm3, Mr = 667.97, F（000） = 1376.0, μ = 0.909 mm-1, Z = 4, the final R = 0.0481 and wR = 0.1304 for 7027 observed reflections with 1 〉 2a（/）. Complex 2 also belongs to the monoclinic space group P2Jn, with a = 13.6326（4）, b = 14.6432（4）, c = 14.9395（5）A, β = 93.132（1）°, V= 2977.84（16） A3, D, = 1.613 g/cm3, ）14,. = 1445.98, F（000） = 733.0,/1 = 0.794 mm-1, Z = 2, the final R = 0.0283 and wR = 0.0784 for 7230 observed reflections with I 〉 2σ（I）. Both complexes 1 and 2 form 2D net structures, which are further linked to form 3D supramolecular net structures via intermolecular hydrogen bonds and aromatic π-π stacking interactions.

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.

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.

Syntheses,Structures,and Properties of Two New Coordination Polymers Based on Tetracarboxylate and 2,2′-Bipyridine Mixed Ligands

Two new coordination polymers {[Zn2L1（2,2＇-bpy）2（H2O）2]·4H2O}n（1） and [Zn2L2（2,2＇-bpy）2（H2O）2]n（2）（H4L1 = terphenyl-2,2＇,4,4＇-tetracarboxylic acid, H4L2 = quarterphenyl-2,2＇,4,4＇-tetracarboxylic acid, and 2,2＇-bpy = 2,2＇-bipyridine） have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction studies. Complex 1 displays 2D wavelike networks, which are further joined together through O–H···O hydrogen bonds to give a 3D supramolecular network. Complex 2 exhibits 1D ladder-like chains, and they are further joined together by π-π stacking and O–H···O hydrogen bonding interactions to form a 3D supramolecular network. The results indicate that the backbone of carboxylate ligands has significant effects on the formation and structure of the resulting functional coordination polymers. Additionally, thermal stability and photoluminescent properties of 1 and 2 are also investigated in detail.

Structural Diversity and Photoluminescent Properties of Two Mn(Ⅱ) Sulfoterephthalate Complexes from Multi-pyridine N-containing Ligands

Solvothermal reaction of manganese（II） salt with monosodium 2-sulfoterephthalate（2-NaH2stp） and two multi-pyridine N-containing auxiliary ligands results in the formation of two new complexes formulated with [Mn2（Hstp）2（bpp）2（H2O）4]（1） and [Mn3（stp）2（tpy）3（H2O）]（H2O）5（2）（bpp = benz-2,3-pyrimidine-[2,3-f]-1,10-phenanthroline, tpy = 2,2＇：6＇,2＇＇-terpyridine）. X-ray diffraction structural analyses of two complexes reveal their structural diversity（0D and 1D） due to the difference of auxiliary ligands. 1 is a discrete structure, in which the Mn（Ⅱ） ion is hexa-coordinated with one stp, one bpp ligand and two water molecules. Complex 2 is a one-dimensional（1D） chain-like structure with three crystallographically independent Mn（Ⅱ） ions. The photoluminescent properties could be assigned to the π-π＊ transition of 2-sulfoterephthalate ligands.

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.

Photoluminescent properties of Ca_2Gd_8(SiO_4)_6O_2: Dy^(3+) phosphor films prepared by sol-gel process

There are growing interests on phosphor thin films owing to their potential application in high-resolution devices such as cathode ray tubes and flat panel display devices. The solution-based sol-gel method is one of the most important techniques for the synthesis of various functional coating films. Compounds with the apatite structure are very suitable host lattices for various luminescent ions. Ca2RE8（SiO4）6O2 （ RE=Y, Gd, La ） is a kind of ternary rare-earth-metal silicate with oxyapatite structure, which has been used as host material for the luminescence of various rare earth and mercury-like ions. In this article, Ca2Gd8（SiO4）6O2：Dy^3＋phosphor films were dip-coated on quartz glass substrates through the sol-gel process. X-ray diffraction （XRD）, atomic force microscopy （AFM）, photoluminescence （PL） spectra, as well as lifetimes were used to characterize the resulting films. AFM study revealed that the phosphor films consisted of homogeneous particles. The Dy^3＋ showed its characteristic emission in crystalline phosphor films, i.e., ^4F9/2-^6H15/2 and ^4F9/2-^6H13/2.

Two Zn(Ⅱ)/Cd(Ⅱ)Metal-organic Frameworks Constructed from 1,3,5-Benzenetricarboxylic Acid and 1,4-Bis(1-imidazolyl)benzene:Syntheses,Structures and Photoluminescent Properties

Two new d;metal-based metal-organic frameworks,{[Zn;（btc）;（bib）;（H;O）;]·2H;O};（1）and{[Cd;（btc）;（bib）;（H;O）;]·6H;O};（2）(btc=1,3,5-benzenetricarboxylate anion,bib=1,4-bis（1-imidazolyl）benzene)have been prepared under hydrothermal conditions by the reactions of d;metal oxides of ZnO and CdO with the aromatic polycarboxylic H;btc and the N-heterocyclic bib.The two products were characterized by single-crystal X-ray diffraction analysis,elemental analysis,thermogravimetric analysis（TGA）,and IR spectroscopy.Complexes 1 and 2 crystallize in monoclinic C2/c and triclinic P 1 space groups,respectively.1 shows a 3D framework,and the potential large voids of the 3D network lead to a 3-fold interpenetrating architecture.2 displays a 2D framework,and the adjacent 2D layers expand into a 3D supramulecular network via rich hydrogen bonds.Moreover,the luminescent properties of the two complexes are investigated in solid state.

Synthesis,Crystal Structure and Luminescent Properties of a Nd(Ⅲ) Complex Constructed from 2-Pyridyl-4,5-imidazoledicarboxylic Acid

A new Nd（Ⅲ） coordination polymer [Nd（pidc）（H2O）4]·pidc-·7H2O（1,pidc2-= 2-py-ridyl-4,5-imidazoledicarboxylate） has been synthesized by solvothermal reaction at 120 ℃ and structurally characterized.The complex belongs to triclinic,space group P with a = 9.022（2）,b = 13.731（3）,c = 13.782（3） ,α = 70.87（3）,β = 71.71（3）,γ = 71.71（3）,V = 1488.6（7） 3,Z = 2,Dc = 1.798 g/cm3,S = 1.04,μ = 1.839 mm-1,F（000） = 814,Mr = 805.76,Rint = 0.081 and wR = 0.1644 for 5242 observed reflections（I 〉 2（I））.Each Nd3＋ ion is nine-coordinated by five O atoms from three pidc ligands,and four O atoms from lattice water molecules.Each pidc is coordinated to three Nd3＋ ions with a μ3-κO：κO＇：κO＂,κO＇＂-μ2 coordination mode into 1D chains,which can be further built into a 3D framework through intermolecular N-H···O and O-H···O hydrogen bonds.Photolu-minescent studies have shown that 1 exhibits emission at 439 nm（λex = 395 nm）.

Structures and Photoluminescent Properties of Two Complexes Based on Dipyrido[3,2-a：2？,3？-c]phenazine and 2,4＇-Biphenyldicarboxylic Acid

ABSTRAC Two new complexes [Cd（2,4＇-bpdc）（DPPZ）]2n·n H2O（1） and [Zn（2,4＇-Hbpdc）2（DPPZ）]· H2O（DPPZ = dipyrido[3,2-a：2＇,3＇-c]phenazine, 2,4＇-H2bpdc = 2,4＇-biphenyldicarboxylic acid） have been hydrothermally synthesized. The structure of complex 1 was determined by single-crystal X-ray diffraction diffraction and further characterized by elemental analysis, IR spectrum, powder X-ray diffraction（XRD） and single-crystal X-ray diffraction. Complex 1 has 1D chains, which are further connected by π-π stacking interactions of neighbouring chains, generating a steady 3D supramolecular structure. Complex 2 shows the isolated mononuclear units, which are further extended to a 2D supramolecular layered structure through π-π stacking interactions and hydrogen bonds. Furthermore, complexes 1 and 2 exhibit green photoluminescent properties at room temperature.

Synthesis and Fluorescent Properties of New Binuclear Europiumβ-Diketone Chelates Eu_mY_(1-m)(TTA)_3phen as Red Electroluminescent Materials

A new type of binuclear europlum β-diketone chelates Eum Y1-m(TTA)3 phen (0≤m≤1) and the influence of the proportion of Y on fluorescence intensity of the Eu-complexes were studied. It was found the proportion of Y3+ could affect the fluorescence properties and the film formation seriously. only m≥0.5.Y3+ could increase the luminescent intensity and improve the film formalion. As a resull. three new binuclear europium β-diketone chelales consisted of Eu, Y1-m (TTA)3phen (m=0.9. 0.7 and 0.5) were designed and synthesized. Their structures were elucidated by IR. UV. DSC and Elementary Analysis. Their PL properties were studied. The results showed that the three binuclear europium β-diketone chelates had better PL properties and film formation than Eu(TYA)3phen. They could emit sharply red light, and fluorescenl wavelength of them was all at 613nm (half bandwidth 10nm). They can be used as red organic electroluminescent materials (OELMs) in organic electrolminescent devices (OELDS).

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.