Three New Zn(Ⅱ)/Cd(Ⅱ) Coordination Polymers Constructed with 2-Mercaptonicotinic Acid and 1,2-Di(4-pyridyl)ethylene: Syntheses and Structure Analysis

Three new Zn(Ⅱ)/Cd(Ⅱ) coordination polymers based on 2-mercaptonicotinic acid (H2mna) with 1,2-di(4-pyridyl)ethylene (dpe) introduced as a bridging ligand have been synthesized via hydrothermal method and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR. As reported in this paper, [Zn2(dpe)0.5(mna)2] (1) can be classified as a two-dimensional layer structure in which the 1D chain composed of Zn(Ⅱ) and mna ligands is bridged by dpe ligands, while the complex named [Zn4(dpe)4(mna)4] (2) is a tetra-nuclear cluster compound. These two compounds are further extended to three-dimensional structures by hydrogen bonds along with C-H…π and π…π interactions. Compound 3 with general formular [Cd2(dpe)0.5(mna)2]·H2O belongs to a three-dimensional porous structure in which the 2D metal layers formed by the coordination of Cd(Ⅱ) and mna ligands are connected with the bridging of dpe ligands.     

Synthesis,crystal structures and luminescence properties of europium and terbium picolinamide complexes

The novel coordination structures of europium and terbium chloride-picolinamide complexes （EuCl3-（C6H6N2O）2.5H2O, Eu-pa and TbCl3.（C6H6N2O）2.5H2O, Tb-pa） are reported. The crystal structures in the solid state are characterized by X-ray single crystal diffraction, FTIR, Raman, FIR, THz and luminescence spectroscopy. In the crystal structures, the pyridyl nitrogen and carbonyl oxygen atoms in picolinamide are coordinated to the metal ions to form a five-membered ring structure. The experimental results indicate the similar coordination structures of Eu and Tb-pa complexes and the changes of hydrogen bonds and conformation provide models for the coordination structures of the ligands induced by complexation. The results of lanthanide ions with ligands having amide groups.     

Synthesis and Structural Characterization of Mono- and Di-nuclear Zinc(Ⅱ) Coordination Compounds of Triphenylphosphoniopropionate

Two novel coordination compounds of Zn(Ⅱ) with Ph3P (CH2)2CO-2(L), namely, [ZnL4(H2O)2]·(ClO4)2·2H2O(compound 1) and [Zn2Cl4(μ-L-O,O′)2](compound 2), have been prepared. The single crystal X-ray structure analysis of these compounds indicates that in compound 1 the Zn(Ⅱ) atom is coordinated by four monodentate carboxylato groups on the equatorial plane and two aqua ligands occupy the axial coordination positions. The pendant oxygen atoms form strong hydrogen bonds with the aqua molecules which results in the stability of this structure. In compound 2, two Zn(Ⅱ) atoms are bridged by a pair of carboxylato groups, showing a skew-bridge mode, and thus enabling a long Zn(Ⅱ)…Zn(Ⅱ) separation. As we know, it is a dinuclear coordination compound with the longest Zn…Zn separation.     

Optical and gas sensing properties of mesoporous hollow ZnO microspheres fabricated via a solvothermal method

Mesoporous,hollow Zn O microspheres were synthesized via a hydrothermal method,using glycerol and zinc acetate as the starting materials.XRD and FESEM analysis showed that the surface morphology of the spheres with a Wurtzite structure could be reasonably adjusted by varying the weight ratio(Rw) of Zn(CH3COO)2 2H2O:H2O:C3H8O3.The responses of the gas sensor based on the spheres to 100 ppm ethanol and 100 ppm acetone are 18.9 and 10.4,respectively.The response and recovery times of the sensor to ethanol and acetone are 2 s and 3 s,3 s and 5 s,respectively.The hollow spheres show an intense UV emission at 392 nm and a broad blue-green emission at 488 nm.Interestingly,a light trapping phenomenon is revealed by UV emission and scattering measurements on the microspheres,which can be attributed to the mesoporous shell and hollow structure of the microsphere.     

Hydrothermal Syntheses,Crystal Structures and Luminescence Properties of Zn(Ⅱ) and Cu(Ⅱ) Complexes Based on 2,2'-((Sulfonylbis(4,1-phenylene))bis(oxy))diacetic Acid

The 2,2'-((sulfonylbis(4,1-phenylene))bis(oxy))diacetic acid(H2L) and 4,4'-bipyridine(4,4'-bipy) are employed as organic ligands to react with metal salts to obtain two new metal-organic frameworks(MOFs), namely [M2L2(4,4'-bipy)](M = Zn(1), Cu(2)). They have been successfully synthesized under hydrothermal conditions. Single-crystal X-ray diffraction reveals that two complexes are isostructural and crystallize in orthorhombic system with space group Pbcn. All L^2- ligands bridge metal ions to form an infinite 1D Z-shaped chain along the a axis. Then through 4,4'-bipy, contiguous Z-shaped chains are linked to form a 2D layer structure. The luminescent studies of the H2L ligand and complex 1 in the solid state and thermogravimetric analyses(TGA) of two complexes are investigated.     

Synthesis and Crystal Structure of Ag2（admtrz）2（CF3CO2）2（admtrz=4—amino—3,5—dimethyl—1,2,4—triazole）

1 INTRODUCTION Transition metal complexes bridged by 1, 2, 4-triazole group can produce interesting structures and specific properties[1]. Many attempts have been made to synthesize a variety of complexes with paramagnetic centers by using such ligands, and their structures and magnetic properties have been characterized[2]. However, the polynuclear Ag(I) complexes bridged by 1, 2, 4-triazole have been poorly studied[3]. Recently, we have prepared a series of silver(I) triazole complex…     

Tuning the Photoluminescence of Zn(Ⅱ) Coordination Polymers by Changing the Coordinated Solvent

By using solvothermal method,two new Zn(Ⅱ) coordination polymers based on 2,5-furandicarboxylic acid(H_2FDA) ligand,[Zn(FDA)(CH_3OH)]_n(1) and [Zn_2(FDA)_2(CH_3CH_2OH)_2]_n(2),were synthesized and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR.Complexes 1 and 2 are isostructural coordination polymers with two-dimensional sheet structures bridged by the protonated carboxylates ligands.The 2D network can be rationalized as a 3-c net with Schl?fli symbol is 82·10.Although 1 and 2 are isostructural,the photoluminescent intensity of 2 is almost twice that of 1 due to the difference of coordinated solvents.     

5,10,15,20-Tetrakis （p-4-fluorobenzoyloxy） phenyl Porphyrin and Its Transition Metal Complexes

The properties of porphyrins can be changed through the choice of peripheral substituents and inserted metal ions. To obtain porphyrin complexes with novel structures, 5,10,15,20-tetrakis(p-4-fluorobenzoyloxy) phenyl porphyrin(TFBOPPH2) and its transition metal complexes {TFBOPPM [M=Mn(Ⅲ), Fe(Ⅲ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ)]} were synthesized and characterized by means of UV-Vis, IR photoacoustic spectrometry, 1H NMR, elemental analyses, molar conductance, and XPS methods. A structure is proposed, in which one porphyrin molecule is coordinated with a transition metal ion in a tetradentate fashion, while the chlorine ion is the balanceable anion in Fe(Ⅲ) and Mn(Ⅲ) complexes.     

Synthesis and Crystal Structure of a New Nickel(II) Complex with Unsymmetric Quadridentate Schiff Base Containing Oxime

1 INTRODUCTION The interest in the complexes of transition met-als with ketoxime ligands[1, 2] as potential modelsfor metal binding sites in ferroverdin[3, 4] hasprompted the investigations on the structures andthe overall coordination geometry of the metalcenters in these complexes. Oxime derivatives areinteresting ligands since the ketoximes are foundto chelate transition metals through the N (oxime)and O (ketone) donors[5～10]. Herein we report thesynthesis…     

Two Zinc(Ⅱ) Complexes Based on 7rany-(1R,2R)-cyclohexanediamine: Molecular Structure Analyses and Preparation of Composite Membrane

Two novel complexes Zn2(chda)2(TPA)Cl2(1) and [Zn(chda)2(H2O)2](TPAXH2O)2(2)[chda is a chiral ligand of trans-(1R,2R)-cyclohexanediamine, H2TPA is terephthalic acid] were synthesized at room temperature. The molecular structures of complexes 1 and 2 were identified by single-crystal X-ray diffraction measurement. The results showed that complex 1 had a binuclear structure, each Zn(Ⅱ) ion was four coordinated by two N atoms of chda, one O atom of TPA and one Cl atom, to construct a distorted tetrahedral geometry. For complex 2, the Zn(Ⅱ) ion was six coordinated by two chda molecules and two water molecules to form a ZnN4O2 octahedral geometry. Complexes 1 and 2 further extended into three-dimensional supramolecular frameworks by hydrogen-bonding interactions. Hirshfeld surface analysis and fingerprint plots were used to further analyze the contribution of diflerent intermolecular interactions. Further, a composite membrane [Zn(chda)2(H2O)2](TPA)(H2O)2/CA was prepared by adding 10%(mass fraction) of complex 2 into cellulose acetate using acetone/chloroform( V:V-1:1) as solvent.     

Theoretical Study on the Structures and Magnetic Properties of Metal String Complexes Containing Rigid Equatorial Ligands[Ni_3(L)_4(NCS)_2](L=dzp~-,mpmpa~-,mppda~-,mptpa~-)

Density functional theory at the BP86 level was used to investigate the influence of equatorial ligands on the Ni–Ni interactions and magnetic coupling properties of metal string complexes [Ni_3(L)_4(NCS)_2](L represents the rigid equatorial ligands; L = dzp-(1), mpmpa-(2), mppda-(3), mptpa-(4)). The following conclusions can be drawn.(1) With increasing the radius of the connecting atom in the cental ring in equatorial ligands, the two pyridine rings bend down, resulting in the decreasing distance between the two pyridine-nitrogen atoms and the Ni–Ni distance. Therefore, the strength order of the Ni–Ni interaction is 4 2 3 1. The Ni–Ni interactions in 2 and 4 are stronger than those in Ni_3(dpa)_4(NCS)_2 containing no-rigid equatorial ligands.(2) The calculated-Jab is 4 2 3 1. There are two types of magnetic exchange pathways in these complexes: the σ-type pathway through the Ni_3~(6+) chains and the δ-type pathway through the equatorial ligands. The magnetic coupling through the metals is the dominant part. Hence, the magnetic coupling strength increases with increasing the Ni–Ni interaction. Modifying the radius of the connecting atom may be one of the means to fine tuning of magnetic coupling strength of this kind of metal string complexes.     

Synthesis,Structure, and Luminescent Properties of Two Complexes Based on Flexible Phenylenediacetate Ligand

Two new Zn(Ⅱ) and Cd(Ⅱ) coordination complexes, [Zn(ppda)(idz)]_n(1) and [Cd(mpda)(mbib)]_n(2)(H2 ppda = 1,4-phenylenediacetic acid, H_2 mpda = 1,3-phenylenediacetic acid, idz = imidazole, mbib = 1,3-bis(imidazol-1-ylmethyl)benzene), have been synthesized by using Zn(Ⅱ)/Cd(Ⅱ) salt and phenylenediacetic acid in the presence of different imidazole ligands under hydrothermal conditions, and characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography and thermogravimetric analysis. Complex 1 crystallizes in orthorhombic system, Iba2 space group. The carboxylic acid ligands form a 2 D helical layer with Zn(Ⅱ) ions, and such layers are expanded into a 3 D network structure by the force of C–H×××π. Complex 2 crystallizes in monoclinic system, P2_1/n space group. Complex 2 shows a 3 D framework with two Cd(Ⅱ) ions as nodes of a dual-core unit, which can be considered to be 6-connected net and regarded as a rare(4~4,5~(10),7) topology network with self-interlacing. The structural diversities indicate that rigid and flexible imidazole ligands play dominating roles in modulating the formation of structures of these crystalline materials. Moreover, the luminescent properties of two complexes are investigated in solid state.     

Polymerization of lactic <Emphasis Type="Italic">O</Emphasis>-carboxylic anhydride using organometallic catalysts

The ring-opening polymerization of 5-methyl-1,3-dioxolane-2,4-dione(lactic O-carboxylic anhydride,LacOCA) using organometallic complexes,including Co(Ⅲ) complexes with Schiff base ligands,Tin(Ⅱ) alphatates and Al(Ⅲ) complexes with Schiff base ligands,was explored.The polymerization was carried out by treatment of the organometallic complexes with LacOCA in toluene under mild conditions.The corresponding poly(lactic acid) was characterized by spectroscopy and thermal analyses,which revealed insight into the structure of the effective catalyst for the polymerization of LacOCA.     

Synthesis and Structure of Bis（indene—1,2,3—trione 2—oximato）bis （aqua）Mn（Ⅱ）：Mn（C9H4NO3）2（H2O）2

1 INTRODUCTION The interest in the complexes of transition metals with ligands ketoxime[1, 2] as potential models for metal binding sites in ferroverdin[3, 4] has prompted the investigation on the structures and the overall coordination geometry of the metal centers in these complexes. Oxime derivatives are interesting ligands since the ketoximes are found to chelate transition metals through the N (oxime) and O (ketone) atoms[5, 6]. However, monodentate coordination via only one O or …     

Preface: Special topic on Metal-organic frameworks (MOFs)

正Metal-organic frameworks,MOFs,are coordination networks with organic ligands and voids.At the fundamental level,MOFs epitomize the beauty of chemical structures and the power of combining organic and inorganic chemistry,two disciplines that are often regarded as disparate.MOFs have recently emerged as an extensive class of crystalline materials with ultrahigh porosity and internal surface     

Urothermal Synthesis and Crystal Structure of a Zn（Ⅱ） Coordination Polymer with a 3-D Supramolecular Structure

A new metal-organic coordination polymer [Zn(hfipbb)(e-urea)]n(1,H2hfipbb = 4,4'-(hexafluoroisopropylidene)bis(benzoic acid),e-urea = ethylene urea) has been urothermally synthesized and characterized by elemental analysis and single-crystal X-ray diffraction.The title complex crystallizes in monoclinic,space group P21/c with a = 13.302(4),b = 10.981(3),c = 13.804(4) ,β = 93.587(5)°,V = 2012.3(10) 3,C20H14N2O5F6Zn,Mr = 541.72,Z = 4,Dc = 0.447 g/cm3, = 0.328 mm-1,F(000) = 272,R = 0.0340 and wR = 0.1107 for 4528 observed reflections(I >2σ(I)).In the structure of compound 1,two Zn(Ⅱ) ions are bridged by two carboxylate groups from two hfipbb ligands to form a dinuclear unit,and each dinuclear Zn(Ⅱ) unit is linked with its two adjacent dinuclear units through four hfipbb ligands into an infinite one-dimensional double-chain.The interesting structural feature of compound 1 is that the one-D double-chains are self-interconnected into a three-D supramolecular structure through hydrogen bonds between the coordinated e-urea molecules and carboxylate oxygen atoms(N1 and O2,N2 and O4).     

X-RAY STUDIES ON THE STRUCTURE OF DES-PENTAPEPTIDE INSULIN AT 2.4 RESOLUTION——THE DPI MOLECULE AND ITS STRUCTURAL RELATIONSHIP WITH INSULIN

The structure of the monomeric insulin analogue des(B26—B30) insulin is presented.; A detailed comparison with the 2Zn insulin structures shows that while there are some large changes in the structure, the basic secondary structural units maintain their integrity. The DPI structure is broadly similar to molecule Ⅰ in the 2Zn structure, and in this respect is like other crystal forms of insulin. In addition to changes on the surface of the structure there are some subtle but extensive changes in the heart of the molecule. The molecules are closely packed in the crystal with many and varied contacts, including a complex network of protein-cadmium interactions and a considerable number of water mediated contacts. The molecular surface has an unusually large number of hydrophobic groups which tend to cluster in a thick band running around the protein. The crystal structure is well ordered, indeed the clarity of some side chains and the definition of the water molecules is superior to that found in the mor     

Synthesis, Crystal Structure and Properties of a New One-Dimensional 3d-4f Compound

Introduction Recently cyano bridged 3d-4f heterometallic compounds have attracted much attention because of their interesting structures and magnetic characteristics.1 The most successful and often the sole strategy for preparing these materials consists in assembling two building blocks that are transition and lanthanide metal complexes, one with terminal ligands that are able to act as bridging ligands and the other with available co-ordination sites. The [M(CN)4]2- (M=Ni, Pd, Pt),1f,2 [M…     

Synthesis and One－dimensional Structure of Cobalt（Ⅱ） Complex [－ （NaOC2H5） CoL2]n

The treatment of bis (2-hydroxybenzyl)-amine (HL) with NaOH and Co ( Ⅱ )(NO)2 gives isostructural one-dimensional coordination polymers [-(NaOC2H5)CoL2]n(1). The cobalt ions have an octahedral geometry and are coordinated by two erystallographicaUy independent ligands which are further linked by β-Ophenol bridged Co and Na atoms to give a one-dimentional structure.     

Effect of Fluorination on the Crystal Structure,Stability and Gas Adsorption Property in Zinc (Ⅱ) Metal-organic Frameworks

Three zinc(Ⅱ) metal-organic frameworks (x F-MAC-3) have been synthesized by using Zn(Ⅱ) salts,3,5-dimethyl-1H-1,2,4-triazole (Hdmtrz) and different fluorination degree carboxylate ligands,which are analogic structures and can be described as (6,6)-connected pcu-b net.We find that the fluorine atoms have structural regulation effect on x F-MAC-3,which can not only enlarge the torsion angle φ of carboxylate ligands but also elevate the space group of structures.Besides,the CO₂-273 K upt...