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Two new metal-organic frameworks, [Zn(Bdc)(Bip)∙H2O] (I) and {[Cd2(Btc)2(H2O)2](H2Bib)· 6H2O} (II) (H2Bdc = 1,3-benzenedicarboxylic acid, H3Btc = 1,3,5-benzenetricarboxylic acid, Bib = 1,4-bis(2-methylimidazol-1′-yl)butane, Bip = 1,5-bis(2-methylimidazol-1-yl)pentane), have been successfully synthesized solvothermally and characterized by elemental analyses, UV−Vis spectroscopy, photocatalysis and single crystal X-ray diffraction (CIF files CCDC nos. 1982779 (I) and 1982780 (II). Complex I exhibits a 3-fold interpenetrating motif having dmp net with {65·8} topology, complex II possesses 3D anionic network comprising of 3,6-connected {4·62}2{42·610·83} topology. These MOFs could be taken as photocatalysts for degrading the methyl violet (MV), in which indicate their effective photocatalytic behavior for the degradation of MV. In addition, the suggested photocatalytic mechanism through density of states plots for I and II was discussed.

Perovskite Ba0.67Sr0.33TiO3 (BST) ceramics with improved dielectric performance were fabricated by a novel direct coagulation casting via high valence counter ions (DCC-HVCI) method using 0.5 mol% MgO as the coagulation agent. The influence of sintering temperature on micromorphology, crystal structure, and dielectric performance of BST ceramic components was systematically evaluated. The densification rate of BST samples could reach the maximum at a heating temperature around 1305 °C and end up approximately at 1380 °C. As increasing the sintering temperature from 1400 to 1550 °C, the relative density of BST ceramics decreases from 98.82 ± 0.16% to 96.72 ± 0.06%, and the mean grain size drops gradually from 9.96 to 4.68 μm. The increased sintering temperature promotes the lattice expansion due to Ti4+ replacement at B site by Mg2+, as well as the generation of oxygen vacancies. In addition, as increasing sintering temperature, the dielectric permittivity (er) of BST ceramic components decreases first and then slightly increases, while the dielectric loss (tanδ) of ceramics shows the opposite trend. The results indicate that the initial tanδ increase is mainly attributed to the lattice expansion of BST ceramics, and the subsequent loss reduction results from the easily localized conduction electrons on Mg2+ sites reducing the carrier concentration. The samples sintered at 1550 °C show the lowest dielectric loss (tanδ≈0.013), which is significantly reduced by an order of magnitude compared with that of dry-pressed samples (tanδ≈0.262).

A new Pb(II) complex, [Pb(8-OQ)(4-NB)], where 8-OQ = 8-hydroxyquinolinate, 4-NB = 4-nitrobenzoate, has been synthesized and characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. The single crystal X-ray analysis reveals that the complex possesses a tetranuclear Pb4O4 cubane structure. The Pb(II) atom is coordinated by three triply bridging phenolic hydroxyl O atoms of 8-OQ ligands, then the tetranuclear Pb system is formed resulting in a tetrahedral cage. The interaction of complex with HS-DNA in Tris buffer was studied by UV−vis absorption spectrum and fluorescence ethidium bromide displacement experiment with an intrinsic binding constant of 1.52×104 M-1 and a linear Stern–Volmer quenching constant of 6.77×103 M-1. Anticancer activity against MCF-7, HepG-2 and A549 cell lines of complex was also determined by the MTT-based assay. The results showed the complex can inhibit proliferation of these three kinds of tumor cells and is less cytotoxic than cisplatin.

Solvothermal reaction of MII (M = Co, Cu) ions with 2,4,5-tri(4-pyridyl)-imidazole (Htpim) gave two MOFs, [Co1.5(tpim)(FA)2(H2O)]n (1) and [Cu2(Htpim)(tpim)(FA)(NO3)2(DMF)]n (2) (HFA = formic acid, DMF = N,N-dimethylformamide). Single-crystal X-ray diffraction analyses indicated that 1 exhibits a 3D {43.412} topology framework assembled by hexanuclear [Co6(FA)8(H2O)4] units and tpim ligands, while 2 presents a 2-D double layer {4.62}2{42.64.82.102}{62.8} network. Hereinto, an inorganic acid was not only used to adjust the pH value of reaction system but also to act as an oxidizing agent to participate in in situ organic reactions. Moreover, 1 displays high sensitivity in the detection of nitrobenzene as a fluorescent sensor and exhibits a relatively good photocatalytic activity toward the degradation of rhodamine B in aqueous solution under UV irradiation.

The requirement of stress analysis and measurement is increasing with the great development of heterogeneous structures and strain engineering in the field of semiconductors. Micro-Raman spectroscopy is an effective method for the measurement of intrinsic stress in semiconductor structures. However, most existing applications of Raman-stress measurement use the classical model established on the (001) crystal plane. A non-negligible error may be introduced when the Raman data are detected on surfaces/cross-sections of different crystal planes. Owing to crystal symmetry, the mechanical, physical and optical parameters of different crystal planes show obvious anisotropy, leading to the Raman-mechanical relationship dissimilarity on the different crystal planes. In this work, a general model of stress measurement on crystalline silicon with an arbitrary crystal plane was presented based on the elastic mechanics, the lattice dynamics and the Raman selection rule. The wavenumber-stress factor that is determined by the proposed method is suitable for the measured crystal plane. Detailed examples for some specific crystal planes were provided and the theoretical results were verified by experiments.

Four new binary complexes with 2-carboxyphenoxyacetic acid ligand (2-H2cpa), namely [Mn(2-cpa)(H2O)3] (0D-Mn), [Cu(2-cpa)(H2O)3] (0D-Cu), [Mn(2-cpa)(H2O)]n (1D-Mn) and [Cu(2-cpa)(H2O)]n (2D-Cu), have been successfully prepared and systematically characterized. Structure analyses indicated that 0D-Mn and 0D-Cu are isomorphous mononuclear species in which the 2-carboxyphenoxyacetate (2-cpa) is a tridentate chelate anionic ligand. 1D-Mn is a 1D zigzag chain structure formed by the tetradentate bridging chelate-μ2 coordination pattern of 2-cpa connecting adjacent MnII ions. While 2D-Cu is a 2D corrugated (4,4)-connected layer and 2-cpa adopts pentadentate double bridging chelate-μ3 coordination mode in it. The different synthetic conditions, crystal structures and conformation of 2-cpa in the above compounds have been carefully analyzed and the results revealed that the synthetic conditions and flexible conformation of 2-cpa may be responsible for the structural diversity of binary 2-cpa metal complex system. In addition, the magnetic measurements showed that between the neighbouring metal ions there are weak ferromagnetic exchange in 0D-Mn and 0D-Cu, but antiferromagnetic coupling in 1D-Mn and 2D-Cu, respectively.

Materials with layered crystal structures and high in-plane anisotropy, such as black phosphorus, present unique properties and thus promise for applications in electronic and photonic devices. Recently, the layered structures of GeS2 and GeSe2 were utilized for high-performance polarization-sensitive photodetection in the short wavelength region due to their high in-plane optical anisotropy and wide band gap. The highly complex, low-symmetric (monoclinic) crystal structures are at the origin of the high in-plane optical anisotropy, but the structural nature of the corresponding nanostructures remains to be fully understood. Here, we present an atomic-scale characterization of monoclinic GeS2 nanostructures and quantify the in-plane structural anisotropy at the sub-angstrom level in real space by Cs-corrected scanning transmission electron microscopy. We elucidate the origin of this high in-plane anisotropy in terms of ordered and disordered arrangement of [GeS4] tetrahedra in GeS2 monolayers, through density functional theory (DFT) calculations and orbital-based bonding analyses. We also demonstrate high in-plane mechanical, electronic, and optical anisotropies in monolayer GeS2 and envision phase transitions under uniaxial strain that could potentially be exploited for nonvolatile memory applications.

Epitaxial thin films of (Ca,Ti) 2 (Nb,Ti) 2 O 7 with pyrochlore structure have been successfully fabricated on orthorhombic (1 1 0) NdGaO 3 substrates by a magnetron sputtering system. By analysis of selected-area electron diffraction patterns, the film-substrate orientation relationship is determined to be 〈0 0 1〉{1 0 0} film //[0 0 1](1 1 0) substrate . Atomic-scale structure investigations of the heterointerface by means of advanced electron microscopy reveal that a perovskite-type Ca(Ti,Nb)O 3 layer with a thickness of several unit cells forms between the (Ca,Ti) 2 (Nb,Ti) 2 O 7 films and the NdGaO 3 substrates. The formation of the Ca(Ti,Nb)O 3 layer results from the demand for accommodation of the crystal structure mismatching between the pyrochlore film and the perovskite-type substrate, which favors the epitaxial growth of the (Ca,Ti) 2 (Nb,Ti) 2 O 7 films on the NdGaO 3 substrates.

β-Sialon:Eu2+ has been reported to be the most promising narrow-band green phosphor for wide color gamut LCD backlights, but the coexistence of the Eu3+ luminescence killer with the Eu2+ luminescence center limits its luminescence performance to a great extent. In this study, we propose a direct reduction strategy to successfully realize the reduction of Eu3+ to Eu2+ and, finally, increase the effective concentration of Eu2+ in the crystal lattice and greatly minimize the amount of Eu3+ on the particle surface. As a result, the luminescence of treated β-sialon:Eu2+ is enhanced by 2.3 times, and the internal quantum efficiency significantly increases from 52.2 to 96.5%. The mechanisms for such large enhancements in luminescence are clarified by investigating the microstructure, luminescence spectra, valence state, concentration, and distribution of Eu using a variety of chemical analyses. We find that the low efficiency is ascribed to the coexistence of the Eu3+ luminescence killer with the Eu2+ luminescen...

Three new complexes, {[Mn(2,2′-bipy)(4,4′-bipy)0.5(4-sb)(H2O)](H2O)2}n (1), [Mn(phen)2(4-sb)(H2O)](4,4′-bipy)0.5(H2O)3 (2), and [Fe2(phen)6](4-Hsb)(H2O)5 (3) [4-sb = 4-sulfobenzoate dianion, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine, phen = 1,10-phenanthroline], have been synthesized and structurally characterized. The interaction of complex with HS-DNA was investigated by carrying out UV−vis absorption spectrum and fluorescence ethidium bromide displacement experiment. The DNA-binding constants Kb of complexes 1, 2, and 3 were calculated to be 7.39 × 105 M−1, 3.94 × 105 M−1, and 9.34 × 105 M−1, respectively. The results indicated that these complexes interact with HS-DNA through intercalative mode. Competitive studies with ethidium bromide (EB) further showed that the complexes bind to DNA probably via intercalation. The complexes were tested for antiproliferative activities on a panel of cell lines (MCF-7, HepG-2, A549, BGC823, and HTR-8) by MTT method, three complexes can inhibit the tumor cell proliferation, but complex 1 is less cytotoxic than other two complexes. The apoptosis assay was assessed with the Annexin-V/PI double staining methods and the results revealed that complexes induced the HepG-2 cells apoptosis.

Pyrochlore-type (Ca,Ti)2(Nb,Ti)2O7 thin films have been grown on single-crystalline LaAlO3 and yttria-stabilized zirconia substrates by a magnetron sputtering system. Atomic-scale interface structure and growth mode of the (Ca,Ti)2(Nb,Ti)2O7 films on the substrates with different crystal structures have been investigated by advanced electron microscopy techniques. In both heterosystems, the film/substrate orientation relationship of [100](001)film//[100](001)substrate has been determined. In the heterosystem of (Ca,Ti)2(Nb,Ti)2O7/yttria-stabilized zirconia, the films directly grow on the substrates. In contrast, in the (Ca,Ti)2(Nb,Ti)2O7/LaAlO3 heterosystem, a perovskite-type Ca1-□(Ti,Nb)O3 interlayer with a few unit cells in thickness forms at the interface and interfacial reconstruction occurs at the (Ca,Ti)2(Nb,Ti)2O7/Ca1-□(Ti,Nb)O3 interface. Our findings indicate that the formation of the interlayer and the (Ca,Ti)2(Nb,Ti)2O7/Ca1-□(Ti,Nb)O3 interface reconstruction can accommodate the film/substrate dissimilarities in the crystal structures and facilitate the growth of single-crystalline pyrochlore-type films on the perovskite-type substrates.

Photoprotection is essential for efficient photosynthesis. Cyanobacteria have evolved a unique photoprotective mechanism mediated by a water-soluble carotenoid-based photoreceptor known as orange carotenoid protein (OCP). OCP undergoes large conformational changes in response to intense blue light, and the photoactivated OCP facilitates dissipation of excess energy via direct interaction with allophycocyanins at the phycobilisome core. However, the structural events leading up to the OCP photoactivation remain elusive at the molecular level. Here we present direct observations of light-induced structural changes in OCP captured by dynamic crystallography. Difference electron densities between the dark and illuminated states reveal widespread and concerted atomic motions that lead to altered protein-pigment interactions, displacement of secondary structures, and domain separation. Based on these crystallographic observations together with site-directed mutagenesis, we propose a molecular mechanism for OCP light perception, in which the photochemical property of a conjugated carbonyl group is exploited. We hypothesize that the OCP photoactivation starts with keto-enol tautomerization of the essential 4-keto group in the carotenoid, which disrupts the strong hydrogen bonds between the bent chromophore and the protein moiety. Subsequent structural changes trapped in the crystal lattice offer a high-resolution glimpse of the initial molecular events as OCP begins to transition from the orange-absorbing state to the active red-absorbing state.

Collagen is one of the most abundant and important proteins in the human body. Human collagen type III (hCOL3A1) belongs to the fibril-forming collagens and is widely distributed in extensible connective tissue like skin, internal organs, or the vascular system. It plays key roles in wound healing, collagen fibrillogenesis, and normal cardiovascular development in human. The charged residues are considered to be an important characteristic of hCOL3A1, especially for collagen binding and recognition. Here we found that a triple helix fragment of hCOL3A1, Gly489-Gly510, contained multiple charged residues, as well as representative Glu-Lys-Gly and Glu-Arg-Gly charged triplets. We solved the crystal structure of this new fragment to a high-resolution of 1.50 Å and identified some important conformations of this new triple-helix region, including strong hydrogen bonds in interchain and interhelical interactions in addition to obvious flexible bending for the triple helix. We also found that the synthetic collagen peptides around this region exhibited potent activities through integrin-mediated peptide-membrane interaction. We then developed a method to produce a recombinant protein consisting of 16 tandem repeats of the triple-helix fragment of hCOL3A1 with strong activity without cytotoxicity. These results provide a strong base for further functional studies of human collagen type III and the method developed in this study can be applied to produce hCOL3A1-derived proteins or other tandem-repeat proteins with membrane adhesion activity., Highlights • hCOL3A1 plays important roles in wound healing and collagen fibrillogenesis. • We solved crystal structure of hCOL3A1's triple-helix region G489-G510 at 1.5 Å. • Peptides overlapping G489-G510 exhibited potent cell-adhesion activity. • T16 protein containing tandem-repeated peptides is more effective than peptides. • This study provides detail structural basis of hCOL3A1 related to its function.

The assembly of 3,3ˊ-(1,2-phenylenebis(methyleneoxy)) dibenzoic acid (H2L) with CoII/CuII salts in presence of 1,1′-(1,4-butanediyl)bis(imidazole) (bbi) ancillary ligand generated two new coordination polymers (CPs) with formula [Co(L)(bbi)]n (1) and [Cu3(μ2-OH)2(L)2(bbi)]n (2). The crystallographic studies revealed that 1 exhibits 2D layer structure, while 2 displays 1D chain. The photocatalytic activities of title materials have been tested for the degradation of a model organic dye methyl violet (MV). The photocatalytic experimental results demonstrated that both 1 and 2 displayed efficient photocatalytic performances to degrade MV under UV irradiation. The mechanisms of these CPs for photocatalytic behaviour have been proposed.

Two binary nickel (II) supramolecular isomers, namely 1D-Ni and 2D-Ni with the same formula [Ni(2-cpa)2(H2O)]n (2-H2cpa ​= ​2-carboxyphenoxyacetic acid), have been prepared by different synthetic methods and systematically characterized. Single-crystal X-ray diffraction analysis shows that the central NiII ion of 1D-Ni is located in a deformed square–pyramid bonded by one water and two 2-cpa anionic ligands. Each 2-cpa exhibits tetradentate bridging chelate-μ2 coordination mode and joins neighbouring NiII ions to form a 1-D zigzag chain structure. While for 2D-Ni, the NiII center is in a distorted octahedral geometry surrounded by one water and three 2-cpa. The 2-cpa displays pentadentate double bridging chelate-μ3 coordination pattern and links adjacent NiII ions to generate a corrugated (4,4)-connected layer. The magnetic measurements indicated that there are both weak ferromagnetic coupling between neighbouring NiII ions in 1D-Ni and 2D-Ni. In addition, the driving force for the formation of two isomers have been carefully analyzed and discussed.

An interesting discrete metallomacrocycle (MMC), [Zn3(L)3(H2O)6] · H2O (I), has been prepared by means of self-assembly of Zn(II) salt, 5-hydroxyisophthalic acid (H2L) as organic linker and 5,5’-(pyridine-2,6-diyl)diisophthalic acid (H4L’) as structure-directing agentunder hydrothermal condition. In complex I, the planar trinuclearmetal-organic macrocycles are arranged into 2D sheet layers connected by strong hydrogen bonded between OH groups of the ligands. Then they stack into 3D supramolecular architecture in–ABAB–array way to give a small 1D open channel along the c axis (CIF file CCDC no. 1053024). Additionally, thermal stability and luminescence properties of I were also investigated.

In the title compound, the two indole ring systems are approximately perpendicular to one another, subtending a dihedral angle of 86.0 (5)°. In the crystal, pairs of N—H⋯O hydrogen bonds link the mol­ecules into the inversion dimers, which are further linked by N—H⋯O hydrogen bonds into supra­molecular chains propagated along the b-axis direction., In the title compound, C29H25FN2O4, the mean planes of the two indole ring systems (r.m.s. deviations = 0.1392 and 0.0115 Å) are approximately perpendicular to one another, subtending a dihedral angle of 86.0 (5)°; the benzene ring is twisted with respect to the mean planes of the two indole ring systems by 83.3 (2) and 88.1 (4)°, respectively. In the crystal, pairs of N—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers, which are further linked by N—H⋯O hydrogen bonds into supra­molecular chains propagating along the [101] direction.

A silver(I) coordination polymer with mixed 3,3′,5,5′-tetramethyl-4,4′-bipyrazole (bpz) and maleic acid, [Ag2(bpz)3(fum)]n (1, H2fum = fumaric acid), was synthesized under hydrothermal condition by in situ isomerization of maleic acid to fumaric acid and characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction, TGA, and single-crystal X-ray diffraction. The maleic acid in situ isomerizes to fumaric acid and participates in the formation of 1. Topologically, the structure of 1 features a rare 3-connected twofold interpenetrated dia-f net with a point symbol of {4.142}. Compound 1 exhibits photoluminescence in the solid state with an emission maximum at 470 nm upon excitation at 365 nm at room temperature, which is attributed to intraligand or/and interligand π → π* transition.

Two new complexes, namely [Cd(L)2(2,2′-bipy)] (1) and [(HL)(4,4′-bipy)0.5((H2O)] (2) (HL = 3-(2-hydroxyphenyl)propanoic acid, 2,2′-bipy = 2,2′-bipyridine and 4,4′-bipy = 4,4′-bipyridine), have been synthesized and structurally characterized by single-crystal diffraction analysis. The structure of complex 1 is molecular dimer, which is connected by stronger hydrogen bond interactions to result in a 2D network. While complex 2 is composed of two organic ligands molecular dimer and one water molecule, which also could be linked into a 2D supramolecular architecture via hydrogen bond interactions. Luminescence and its lifetime for compound 1 have also been explored.

A series of polynuclear metal-oxo clusters have been constructed from the dynamic polyoxometalate (POM) building block {B-α-Sb(III)W9O33} and lanthanide (Ln) linkers via a stepwise synthetic strategy with the molecular formulas of [Ln2(H2O)4{WO2(pic)}2(SbW8O30)2](10-) (Na4Li6[La-1]·28H2O, Na3Li7[Pr-2]·30H2O) and [{Ln(H2O)}{Ln(pic)}(Sb3O4)(SbW8O31)(SbW10O35)]2(24-) (K2Na6Li16[Tb-3]·63H2O, Na9Li15[Dy-4]·61H2O, Na7Li17[Ho-5]·53H2O) (Hpic = picolinic acid). The five compounds have been characterized by FT-IR, elemental analysis, TG, powder X-ray diffraction (PXRD) and single crystal X-ray diffraction. In compounds 1-5, various POM moieties, such as {B-β-SbW8O30}, {B-α-SbW8O31} and {B-α-SbW10O35}, were formed through a series of disassembling and re-assembling processes of the dynamic {B-α-SbW9O33} precursor with specific pH, reaction temperature and time. Furthermore, the use of oxytropic Ln(3+) ions as linkers, together with auxiliary organic pic ligands and/or inorganic Sb(3+) ions, led to diverse connection modes between the POM building blocks and Ln linkers and the assembly of new polynuclear metal-oxo clusters. The polyoxoanions of La-1 and Pr-2 possess the same structural feature, which can be viewed as a sandwich-type cluster composed of two {B-β-SbW8O30} units connected by two {WO2(pic)} fragments and two hydrated Ln ions. These sandwich-type polyoxoanions are further linked by the hydrated Ln ions to form a 1-D helical chain. The polyoxoanions of Tb-3, Dy-4 and Ho-5 display the same structural features, although they contain different counter-cations and lattice water molecules. In the polyoxoanions of 3-5, one {B-α-SbW8O31} POM moiety and one {B-α-SbW10O35} POM unit are connected by one {Sb3O4} fragment and one {Ln(pic)} linker, forming an asymmetric sandwich-type metal-oxo cluster. Two of these sandwich-type clusters are further fused together by extra two hydrated Ln ions, leading to an isolated polynuclear metal-oxo cluster with a size of 16.4 × 28.5 Å. The photoluminescence properties of Tb-3 and Dy-4 were investigated. Both compounds exhibit characteristic Tb(3+) and Dy(3+) luminescence. The relationship between the luminescence properties and the crystal structure of the polyoxoanion was discussed.

A series of Li2Fe1-xVxSiO4/C (x = 0.00, 0.03, 0.05 and 0.07) composites have been synthesized via a refluxing-assisted solid-state reaction. XRD results confirm the monoclinic structure with space group P21 for Li2Fe1-xVxSiO4/C compounds. TEM and Raman spectroscopy demonstrate V-doping can increase the graphitization degree of residual carbon. XPS confirms that V-incorporation does not change the divalent state of Fe, and the oxidation state of V in V-doped Li2FeSiO4/C is +3. Combined Ar-ion sputtering with XPS, it is found that V has been successfully doped into the crystal lattice of Li2FeSiO4. Electrochemical tests show that LFS/C-5 V delivers the highest initial discharge capacity of 220.4 mAh g−1 and the biggest Li-ion diffusion coefficient of 1.60 × 10−11 cm2 s−1. In addition, the density functional theory (DFT) calculations predict that V-doping decreases the electronic band gap of Li2FeSiO4, thus leads to significant improvement in the electrical conductivity of Li2FeSiO4. The enhanced electrochemical performance can be attributed to the increased electronic conductivity, the decreased charge transfer impedance, and the improved Li-ion diffusion coefficient. Our results clarified the nature of V doping into Li2FeSiO4 and demonstrated that V-doping is a promising approach to improve the electrochemical performance of Li2FeSiO4.

A series of Li2−xNaxFe0.5Mn0.5SiO4/C (x = 0.00, 0.01, 0.03 and 0.05) composites have been synthesized via a refluxing-assisted solid-state reaction, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), galvanostatic charge–discharge measurements, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests. XRD results show that Li2−xNaxFe0.5Mn0.5SiO4/C can be well indexed as the structure of two mixed polymorphs with space group P21 and Pmn21. XPS results confirms that Na not only exists on the surface of Li2Fe0.5Mn0.5SiO4 particles, but also has been successfully doped into the crystal lattice of Li2Fe0.5Mn0.5SiO4. Na-doping can significantly improve the discharge capacity and the rate capability of Li2Fe0.5Mn0.5SiO4/C. The enhanced electrochemical performance can be attributed to the increased electronic conductivity, the decreased charge transfer impedance, and the improved Li-ion diffusion coefficient.

Two new metal carboxyphosphonates with 3D framework structures, [Sn2(HL)·2H2O] (1) and [Pb2Cl(H2L)] (2) (H5L = 4-HOOCC6H4CH2N(CH2PO3H2)2), have been synthesized under hydrothermal conditions. For compound 1, every two Sn(1)O3 and Sn(2)O3 polyhedra are linked by CPO3 tetrahedra to form a 2D inorganic layer via corner-sharing in the bc-plane. Then the adjacent layers are further assembled into a 3D supramolecular structure through π–π stacking interactions. Compound 2 features a 3D open-framework structure. The Pb(1)O5Cl, Pb(2)O5 polyhedra and CPO3 tetrahedra are interconnected into a 2D inorganic layer via corner-sharing in the ac-plane. Such layers are further connected through carboxyphosphonate ligands to form a 3D open-framework structure. The luminescent properties of compounds 1 and 2 have also been studied.

Two new mononuclear nickel(II) complexes, [NiL1(NCS)] (1) and [Ni(L2)2]·2NO3 (2), where L1 is the deprotonated form of 1-[(2-ethylaminoethylimino)methyl]-naphthalen-2-ol, and L2 is the zwitterionic form of 2,4-dibromo-6-[(2-ethylaminoethylimino)methyl]phenol, have been prepared and characterized by physico-chemical methods and single-crystal X-ray diffraction. The Ni atoms in both complexes are in square planar coordination. The Ni atom in 1 is coordinated by one phenolate O, one imine N, and one amine N atom of L1 ligand and one thiocyanate N atom. The Ni atom in 2 is coordinated by two phenolate O and two imine N atoms of two L2 ligands. Crystals of the complexes are stabilized by hydrogen bonds. Thermal stability of the complexes has been studied. The Schiff bases and the complexes showed potent antibacterial activities.

A new one-dimensional (1D) coordination polymer, [Pb2(psa)(phen)2(NO3)2]n, has been synthesized by the method of hydrothermal reaction and characterized by elemental analysis, FT-IR and X-ray single-crystal diffraction (where H2psa is phenylsuccinic acid and phen is 1,10-phenanthroline). The single-crystal X-ray analysis showed that the complex has a dinuclear core stabilized by bridging phenylsuccinic acids and nitrate anions. The coordination number of the two Pb(II) atoms are 7 and 6, with the stereochemically active lone pair, resulting in the hemidirected geometry for the complex. The complex contain a 1D chain, which is further extended into two-dimensional supramolecular architecture through hydrogen bonds, C-H···π, and π···π interactions.

Three novel metal carboxyphosphonates with a 3D pillared-layered structure, namely, [Mn(HL)] (1), [Co(HL)]·H2O (2), and [Cd3(L2)(H2O)3] (3), (H3L = 4-HOOCC6H4CH2NHCH2PO3H2), have been hydrothermall...

Two new cobalt phosphonates, [enH 2 ] 0.5 [Co(HL)(H 2 O)] · H 2 O (1) and [Co 2 (HL)(H 2 L) 2 ] · 2NH(CH 3 ) 2 · 3H 2 O (2) (H 3 L = 2-hydroxyphosphonoacetic acid; en = ethylenediamine), have been synthesized under hydrothermal conditions and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. For compound 1 , Co(II) atoms are octahedrally coordinated. The CoO 6 octahedra and CPO 3 tetrahedra are linked by HL 2 − into a 2D layered structure in the bc -plane. The ethylenediamine molecules and solvate water molecules are located between two adjacent layers. The structure of compound 2 composed of Co1O 6 and Co2O 6 octahedra via bridging phosphonate ligands leads to a 2D layered structure with one-dimensional channel system along c -axis direction. The dimethylamine molecules and solvate water molecules are located between two adjacent layers. The surface photovoltage properties of compounds 1 and 2 have also been studied.

By the introduction of oxalate as the second ligand, five new lanthanide oxalatophosphonate hybrids with a 2D layered structure, namely, [Ln(H2L)(C2O4)(H2O)]·2H2O [Ln = Nd (1), Sm (2), Eu (3), Tb (4), Dy (5), H3L = H2O3PCH2NCH2(CH2CH2OPO2H)], have been hydrothermally synthesized and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. Compounds 1-5 are isostructural and exhibit a 2D layer formed by the interconnection of a 1D zigzag chain of {Ln(C2O4)}(+) with the phosphonate ligands. The effect of lanthanide contraction induces the decrease of the lattice parameters and crystal size from Nd to Dy. The luminescence properties of compounds 2-5 have been studied.

A powder of oxyfluorotitanate Na3TiOF5crystals is acquired as an intermediate product during the synthesis of anatase titanium dioxide (TiO2) nanosheets with a large percentage of exposed reactive {001} facets. By application of transmission electron microscopy techniques, mainly energy dispersive spectroscopy and selected-area electron diffraction, coherent domain variants of Na3TiOF5are shown to possess monoclinic structure with space groupP21/n. The occurrence of these orientation domain variants is attributed to the reduction of crystal symmetry as a result of the phase transition from the high-temperature cubic phase to the low-temperature monoclinic phase. Through a detailed group theory analysis, the orientation domains are shown to exhibit 12 variants and 11 domain boundaries, which can be categorized into three types of perpendicular twins and two types of antiparallel twins. This work may provide meaningful insight for understanding the growth mechanism of anatase TiO2with a high percentage of reactive facets.

afforded the mononuclear [Cd II (H2bptc)(H2O)3]·H2O (1), linear {[Cd(H2bptc)(H2O)]·3H2O}n (2), 3-D heterobimetallic [NaCd(Hbptc)(H2O)] (3), layer [Mn(H2bptc)(H2O)]n (4) and a dinuclear compound [Ni2(H2bptc)(H2O)2]·6H2O (5). These compounds have been characterized by elemental analysis, IR, and their structures have been determined by X-ray crystallography. The thermal stabilities of 1-3 were measured by thermogravimetric analysis (TGA) and their solid state luminescence properties together with the free ligand H4bptc were investigated at room temperature.

Non-centro-symmetric characteristics are observed in the experimental electron diffraction patterns (EDPs) from the icosahedral quasicrystalline precipitates in ZrAlNiCuNb alloys. Different from the well-known breaking of the Friedel's law, where a strong dynamical effect will reveal in EDPs the concealed non-centro-symmetry originated from the crystal structures themselves, the current results can be interpreted in terms of changes in deviation parameters due to a delicate combination of the linear phason strain characteristic of quasicrystals and the curvature of Ewald sphere. After taking this effect into consideration, the corresponding simulated EDPs fit quite well to the experimental data.

Two new complexes, namely [Cu(L1)(NO3)(bipy)] (1) and [Cu2(L2)4(H2O)2] (2) (HL1= 2-ethoxynicotinic acid, HL2= 2-methoxynicotinic acid and bipy=4,4′-bipyridine) have been synthesised and structurally characterised by single-crystal diffraction analysis. The structure of complex 1 is a ladder-like chain, which is connected by stronger hydroge n bond interactions to result in a 2D network. While complex 2 is composed of molecular dimmer based on a paddle-wheel unit with two coppers, four syn–syn carboxylates, and two water molecules coordinated to copper in the axial positions which could also be linked into a 2D supramolecular architecture via hydrogen bond interactions. Magnetic studies reveal the overall antiferromagnetic interactions between neighbouring Cu(II) ions in compounds 1 and 2.

Two new complexes, [Cd(hpdaH)(H2O)1.5]2n.n(bpp) (1) and [Ni(hpdaH)(2′2-bipy)H2O]·(H2O)2(2) (hpdaH3 = 4-hydroxy- pyridine-2,6-dicarboxylic acid, bpp = 1,3-bi(4-pyridyl)propane, 2,2′-bpy = 2,2′-bipyridine), were synthesized under hydrothermal conditions at 140°C and were characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction. Both crystallize in monoclinic system, space group Pc with a = 12.4435(15), b = 9.0015(11), c = 13.7170(17) A, β = 99.9970(10)°, Z = 4 for 1 and space group P2(1)/n with a = 17.0228(14), b = 11.1624(9), c = 19.9271(16) A, β = 93.9050(10)°, Z = 8 for 2. X-ray analysis demonstrates that complex 1 has a novel one-dimensional coordination polymeric structure linked by two kinds of bridging groups in an alternating manner. Complex 2 contains a mononuclear Ni(II) complex and two solvate water molecules. Furthermore, two complexes extend to supramolecular architectures via rich hydrogen bonding interactions.

A new metal-organic framework, [Mn2(L)(4,4-bipy)2(H2O)3]n (1) (H4L = 4,4′-diazenediyldiphthalic acid and 4,4′-bipy = 4,4′-bipyridine), has been synthesized through the hydrothermal method and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group Cc with a = 23.406 (10) A, b = 16.651(8) A, c = 10.363 (5) A, β = 103.437(9)°. The complex exhibits interesting 2D (6,4)-connected framework with (36,44.65)(42,84) topology. The motif is further extended into 3D supramolecular architecture via hydrogen bonding interactions.

High yield of β-Ni(OH)2 was synthesized by hydrothermal reaction. After heat treatment, novel NiO nanosheets with hexagonal nanopores were obtained. Transmission electron microscopy was employed to investigate the morphology and the crystallographic structure of the products, which indicated that the nanosheets were commonly ⟨111⟩ orientated and the nanopores were bounded by {111} and {100} planes. Meanwhile, the nanosheets were oxygen-sufficient based on the electron energy loss spectroscopy. The mechanism associated with formation of the hexagonal nanopores was discussed according to structural evolution. This unique morphology and the chemical characteristics were considered as the probable key factor responsible for its excellent performance on catalysis, gas sense, and adsorption.

A new two-dimensional Cu(I)-framework [Cu3(deppz)(mtta)I] (1) [(Hdeppz = 3,5-diethyl-4-(4-pyridyl)-pyrazole, Hmtta = 5-methyltetrazole] has been solvothermally synthesized and structurally characterized. The framework contains an unprecedented cyclic Cu4(μ-pz)2(μ-mtta)2 cluster (Cu4) with twelve-membered coplanar Cu4N8 metallocycle, which contains coordinatively unsaturated Cu(I) centers and acts as a soft π-acid motif to contact with iodine atoms from Cu2I2 dimer of adjacent layers, generating a 3D supramolecular framework. The framework exhibits high thermostability and bright green-blue solid-state luminescence.

The structures, formation energies and elastic constants of α-U, β-U, γ-U, fcc-U, hcp-U and bct-U were investigated by first principles calculations. It turns out that the structures described by the space groups no. 118 and 136 can be identical for the β-U and that the symmetry of β-U should belong to the space group no. 136. Interestingly, it is also shown that β-U might exhibit some isotropic behaviors and that both γ-U and fcc-U are unstable in the ground state because their Zener's shear constants are negative. The results and conclusion obtained in present study are supported by or consistent with others theoretical prediction and experimental observations.

Two new metal-organic frameworks, [Mn(aobtc))0.5 (phen)2·2H2O·H2hb] (1) and [Cu(phen)2Cl·H3DDA·H2O·HAC] (2) (H4aobtc = azoxybenzene-3,3′,4,4′-tetracarboxylic acid, H4DDA = 4,4′-diazenediyldiphthalic acid, H2hb = p-hydroxybenzoic acid and phen = 1,10-phenanthroline), have been synthesized and characterized by IR and single-crystal X-ray diffraction. Complex 1 exhibits interesting 1D chain structure containing dinuclear Mn subunits, which is further extended into 3D supramolecular double chain via π–π interactions and hydrogen-bonding interactions. Compound 2 has a monomer with [Mn(phen)2Cl]+ unit. The structural analysis reveals that the assistant ligand has critical effect on the construction of the complexes.

The metal–organic framework, [Mn2(H4DDA)(phen)2(H2O)5]·4.55H2O (H4DDA = 4,4'-diazenediyldiphthalic acid and phen=1,10-phenanthroline), has been synthesised and characterised by IR and single-crystal X-ray diffraction. The complex has a 2D layer structure, which extends into a 3D supramolecular framework via hydrogen bonds.

Research on structure-property relationships in distyrylarylene derivatives is far behind their wide applications in optoelectronic devices due to the absence of crystal structure information. Herein, the single crystals of 4,4'-bis(2-thienylvinyl)biphenyl (1) and 4,4'-bis(2-thieno[3,2-b]thienylvinyl)biphenyl (2) were successfully grown by the vapor transport method. Both molecules adopt the typical herringbone packing motif. However, the intermolecular C-H⋅⋅⋅π interaction in compound 2 is much stronger than that in compound 1. The correlations of interchain interaction with film morphology, optical and electronic properties were studied. Compound 2 formed higher crystalline films with (001) and (111) orientations. The organic field-effect transistor properties of both materials were investigated. Compound 2 showed better performance with a hole mobility higher than 0.01 cm(2) V(-1) s(-1) and an on/off current ratio over 10(6) . These results reveal that the intensity of C-H⋅⋅⋅π interactions can exert dramatic influences on the optical and electronic properties of distyrylarylene-based materials.

An exploration of the cadmium-L system under hydrothermal condition, has led to the isolation of a novel framework {[Cd(L)0.5(H2O)3]}n (1) (H4L = 4,4'-diazenediyldiphthalic acid). Single-crystal X-ray analysis reveals that it crystallizes in the triclinic space group P-1. a = 5.746(3) A, b =6.526(4) A, c = 14.701(8) A, α=92.348(8), β = 99.622(6), γ=106.877(7)°. The CdII ions are linked into an extended 2-D rectangle-like structure via L ligands, which exhibits an attractive three-connected honeycomb topological network. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Two new copper(II) complexes were synthesized from 2-hydroxyl-4-methoxyacetophone with R-NH–CH2–CH2–CH2–NH2 (for complex 1, R = H; complex 2, R = C6H5–CH2–) in the presence of Cu2+. Crystals of 1 were monoclinic, space group P21/n, with a = 12.6408(10) A, b = 7.4063(6) A, c = 16.8863(14) A and β = 93.3590(10)°, complex 2 crystals were triclinic, space group P with a = 7.561(3) A, b = 10.680(4) A, c = 13.868(5) A and α = 97.389(6)°, β = 95.240(6)°, γ = 101.206(6)°. Both Cu(II) atoms were four-coordinate with distorted square-planar geometry. The toxicity of 1 and 2 were evaluated by testing antimicrobial activity against bacterial strands.

Two new copper(II) complexes were synthesized by reaction of N-(3-aminopropyl)benzylamine (L1: apba, for complex 1) and N-salicylidene-apba (L2: for complex 2) with Cu2+. Crystals of complex 1 were orthorhombic, space group pccn, with a = 15.2149(10), b = 25.0071(16), c = 7.6280(5) A and α = β = γ = 90°. Complex 2 crystals were monoclinic, space group P21/c, with a = 8.688(6), b = 12.812(9), c = 16.022(11) A and β = 99.241(10)°. Structures of the two complexes were centro-symmetric and both Cu(II) atoms were four coordinate with a distorted square-planar geometry. The toxicity of the complexes was evaluated by testing antimicrobial activity against bacterial strands.