•High adsorption and catalytic active with extremely low content of the N-NpC about 10.7%.•The catalytic efficiency of the ZnO@N-NpC composites up to 93% after reusing for 5 cycles and stored for two months.•The introduction of N-NpC effectively promotes the photo-induced electron-hole pairs separation, resulting in higher photocatalytic activity.This report describes the controllable encapsulation of ZnO nanoparticles with N-doped nanoporous carbon (N-NpC) via a simple fabrication and calcination of ZnO@ZIF-8 (zeolitic imidazolate framework). In the fabrication of ZnO@ZIF-8, ZnO was used both as the support and Zn source for the formation of ZIF-8. After calcination under N2 atmosphere, the ZnO@N-NpC core-shell heterostructures were formed and characterized by IR, UV–vis, XRD, XPS, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). As expected, the well-defined ZnO@N-NpC core-shell nanospheres demonstrated distinct photocatalytic activity and adsorption capacity in response to the dye methylene blue (MB) in aqueous solution, and the degradation efficiency of MB is up to 99% under UV irradiation for 20 min after catalysts were reused for 5 cycles and stored for two months. Therefore, it is reasonable to believe that the ZnO@N-NpC core-shell heterostructures are new-type nanomaterials for photodegradation of the organic pollutants from wastewater.ZnO@N-doped nanoporous carbon (ZnO@N-NpC) core-shell heterostructures were obtained by a calcination of ZnO@ZIF-8 strategy, which exhibited high adsorption and photocatalytic efficiency up to 93% after 5 cycles and stored for two months.Download high-res image (296KB)Download full-size image

•Na2 − 2xBaxLi2Ti6O14 (x = 0, 0.25, 0.5, 0.75, 1) are prepared by solid reaction route.•Na2 − 2xBaxLi2Ti6O14 are good anode materials as lithium hosts.•NaBa0.5Li2Ti6O14 delivers the best lithium storage capability.•A reversible capacity of 98.1 mAh g− 1 can be delivered at 500 mA g− 1.In this paper, a series of Na2 − 2xBaxLi2Ti6O14 (x = 0, 0.25, 0.5, 0.75, 1) samples are prepared simply by a solid state reaction method, and among them, NaBa0.5Li2Ti6O14 (x = 0.5) exhibits the smallest particle size and best electrochemical properties. According to the electrochemical results, the initial charge specific capacity of NaBa0.5Li2Ti6O14 (x = 0.5) reaches 109.6 mAh g− 1 at the current density of 50 mA g− 1, which is much higher than other samples. The reversible capacity can still be held at 108.6 mAh g− 1 after 50 cycles. In addition, NaBa0.5Li2Ti6O14 (x = 0.5) also displays outstanding rate property with high charge specific capacities of 128.8, 117.7, 110, 100.2, 98.1 mAh g− 1 at 100, 200, 300, 400 and 500 mA g− 1, respectively. Our results suggest that the smaller particle size, decreased electrochemical resistance and improved ionic conductivity of Na2Li2Ti6O14 after Ba doping are main contributing factors in enhancing the lithium storage capability, and among them, NaBa0.5Li2Ti6O14 (x = 0.5) is a potential anode material for rechargeable lithium-ion batteries.Download high-res image (300KB)Download full-size image

In this study, a new detection method for glyphosate (GPS) based on an anti-aggregation mechanism by using gold nanoparticles (AuNPs) is proposed. A certain amount of Pb2+ can cause the aggregation of AuNPs because of electrostatic interactions and the color of the solution changed from red to gray. However, in the presence of GPS, the above-mentioned process can be strongly hindered due to the chelation between GPS and Pb2+. Based on this anti-aggregation mechanism, the colorimetric detection method exhibits excellent sensitivity for GPS. The limit of detection (LOD) is 0.5 μM by the naked eye and 2.38 nM by UV-vis spectroscopy. The selectivity of the AuNP detection system for GPS is excellent compared with other pesticides. A good linear relationship (R2 = 0.99695) between the absorption intensity ratio and GPS concentrations indicates that our probe can be used for the quantitative assay of GPS. The detection method has been successfully used for detecting GPS in real environmental samples.

Demonstrated was a simple visual and rapid colorimetric sensor for detection of clenbuterol (CLB) based on gold nanoparticles (AuNPs) modified with cysteamine (CA) and characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV–vis. The solution color from red to blue gray with increasing clenbuterol concentration resulted from the aggregation of AuNPs. The detection limit of clenbuterol is 50 nM by naked eyes. The selectivity of CA-AuNPs detection system for clenbuterol is excellent compared with other interferents in food. This sensor has been successfully applied to detect clenbuterol in real blood sample.Keywords: clenbuterol; colorimetric detection; excellent selectivity; gold nanoparticle; high sensitivity

•The release amount of catalysts could be easily controlled by removing the film.•High catalytic efficiency with extremely low Pd-loading down to 10−6 mol%.•High stability in the air and free phosphorus ligands.To improve the catalytic activity and reduce the dosage of noble metal catalysts has attracted much more attention for organic synthetic chemists. We facilely fabricated multilayer films of PEI-(PdCl2/1)n through layer-by-layer (LBL) self-assembly method (PEI = polyethylenmine, 1 = 2,2′,7,7′-tetra(4-pyridyl)-9,9′-spirobifluorene, psf). UV–vis spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to monitor the growth of multilayer films. X-ray photoelectron spectroscopy (XPS) proved the palladium and ligand 1 were deposited on the film. The PEI-(PdCl2/1)n multilayer films were used as the cisterns of catalysts to gradually discharge high active catalytic moieties in the Suzuki–Miyaura, Heck and Sonogashira cross-coupling reactions. The Pd-loading was as low as 12.1 × 10−6 mol% measured by inductively coupled plasma OES spectrometer (ICP), and gave high yields in the typical reactions of bromobenzenes with phenylboronic acids. The LbL catalyst featured the simplicity of fabrication, high efficiency, reusability, convenient control and no sensitive to air in the reactions.

•V2O5 micro/nanorods are prepared by an electrospinning method.•Inexpensive NH4VO3 and H2C2O4 are used as starting materials.•V2O5 micro/nanorods exhibit the potential as cathode materials.•V2O5 micro/nanorods deliver an initial discharge capacity of 418.8 mAh g− 1.V2O5 micro/nanorods are produced through the heat treatment for the electrospun composite fibers which are prepared by using inexpensive NH4VO3 and H2C2O4 as starting materials at room temperature. Powder X-ray diffraction analysis reveals that the micro/nanorods are orthorhombic V2O5 (space group Pmmn (59), a = 1.1516, b = 0.3566, c = 0.4373 nm), and the results of field emission scanning electron microscopy indicate that the V2O5 micro/nanorods have a diameter of roughly 300 nm and a length-to-diameter ratio of 5–10. Meanwhile, the V2O5 micro/nanorod cathodes show a high lithium storage performance with the first discharge capacity of 418.8 mAh g− 1 and the 50th discharge capacity of 180.5 mAh g− 1 when the half cell is cycled between 2.0 and 4.0 V at a current density of 50 mA g− 1. This is possibly attributed to the fact that the micro/nanostructure samples are well dispersive and they have high structural stability and efficient electron/ion transport in the charging and discharging processes.

A pyridyl fluorene ligand, 2,7-bis(4-pyridyl)-9,9-diethylfluorene (1), has been synthesized by a simple route. The ability of the two linearly terminal pyridyl nitrogen atoms of 1 to coordinate with the Pd(II) or Ni(II) ions has enabled the use of 1 as a linking ligand in the preparation of (PdCl2/1)n, (Ni(NO3)2/1)n films, PdCl2/1 and Ni(NO3)2/1 complex. The resulting films and complexes were characterized by UV–vis spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectrometer. The application of films and complexes as catalysts for Suzuki–Miyaura and Mizoroki–Heck reactions was carried out. (PdCl2/1)n films show high catalytic activity in the reactions with the Pd loading of ppm. (Ni(NO3)2/1)n multilayers as the active catalytic moieties for these reactions were investigated with very low Ni(II)-loading.

A multilayer film of (Pd2+/1)10 was simply fabricated by Pd(II) and 2-Br-2′,7,7′-tri(4-pyridyl)-9,9′-spirobifluorene (1, Br-tpsf) through a layer-by-layer self-assembly method. The film loaded on a quartz slide as a catalyst reservoir could gradually release high active catalytic species to promote Sonogashira, Heck and Suzuki cross-coupling reactions, with extremely low Pd-loading of 11.0 × 10−6 mol% and high catalytic efficiency in EtOH–H2O system.

Gold nanoparticles (AuNPs) modified by 8-hydroxy-quinoline (8-HQ) and stabilized by polyvinylpyrrolidone (PVP) were used for highly selective and sensitive colorimetric detection of Hg2+ based on the quick aggregation of AuNPs leading to a color change from wine red to gray. The limit of Hg2+ detection in real environmental water samples is 4.0 × 10−7 M by the naked eyes and 1.0 × 10−8 M by UV-vis spectroscopy.

•Self-ordering of organic-metal hybrid microstructures based on EDT-TTF-4-py.•The results show the chemical composition of the microstructures is the same as that of bulk crystals.•The crystal structure of 1 and 2 indicates that the two compounds are isostructural.•Complexes 1 and 2 are potential uses as a molecular brick for conducting and magnetic materials.Two divalent transition metal complexes of EDT-TTF-4-py (EDT-TTF-4-py = 4-ethylenedithiotetrathiafulvalenyl-pyridine) have been prepared and characterized in micro and bulk crystal forms. These hybrid microstructures were synthesized by coordinative self-assemble through a solution process. The isostructural Cu(hfac)2 and Mn(hfac)2 (hfac = hexafluoroacetylacetonate) complexes crystallize in the monoclinic space group P21/c. Two pyridyl N atoms from two different molecules of EDT-TTF-4-py are coordinated in the trans configuration to the metal ion of M(hfac)2 to form an octahedral complexes. The results of the elemental analysis, FT-IR, SEM-EDX and PXRD, show the chemical composition of the microstructures which are same as that of bulk crystals. Moreover, these two microstructure compounds are precursor for both conducting and magnetic materials. These investigations show the intriguing potentials of the coordinative bond in the development of multifunctional hybrid microstructures.

•A triad compound, L2 and its protonated products were studied.•The monoprotonated and diprotonated L2 compound are generated.•A unique N+H⋯N H-bonded trimer motif was constructed in 2.•Different conformational states for the pyridyl group in L2 and 2.•The results are completely different with an analog compound, L1.A triad compound, bis(3-py)-substituted TTF (L2) (py = pyridine; TTF = tetrathiafulvalene) was synthesized and characterized. The absorption spectroscopy and electrochemical properties of L2, and its protonated products were studied. The results of electronic absorption spectroscopy and cyclic voltammetry confirm that the mono- and di-protonated species of L2 are successively generated with the protonation processes. A unique N+H⋯N hydrogen-bonded (H-bonded) trimer motif based on the L2 was constructed in the protonated complex. This result is very different from that of an analog triad compound, bis(4-py)-substituted TTF (L1).

The platinum complex [Pt2(CCPy)2(dppm)2] (Py = 4-pyridyl, dppm = bis(diphenylphosphino)methane) 1 has been prepared and characterized. Single crystal X-ray diffraction analysis reveals that the Pt2(CCPy)2 fragment of 1 exhibits an approximately linear molecular geometry, in which the Pt–Pt bond may be considered as having been inserted within the delocalized π-electron system of the 1,4-bis(4′-pyridyl)buta-1,3-diyne. The ability of the two terminal pyridyl nitrogen atoms of 1 to coordinate to other metal centers has enabled the use of 1 as a linking ligand in the layer-by-layer (LbL) growth of heterometallic films. The self-assembly behavior of 1 with Pd(II), supported by chloride counter ions, on poly(ethylenimine) (PEI) functionalized solid surfaces has been investigated. The resulting multilayer films of general composition and form (PdCl2/1)n have been characterized using UV-vis absorption spectroscopy, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). On the basis of the UV-vis spectroscopic data, it was shown that the (PdCl2/1)n multilayer films could be grown in a regular fashion, with film thickness increasing linearly with increasing deposition of the metal–ligand bilayers. Consistent with this metal ion dependent LbL growth, AFM images of the multilayer films exhibited island-shaped nanostructures with a mean diameter of about 25 nm. The catalytic properties of the (PdCl2/1)n multilayers were investigated, and (PdCl2/1)n film-loaded slides were used as a catalyst reservoir capable of liberating catalytic amounts of a highly active Pd species, which was suitable for promoting C–C bond formations. The catalyst loading was as low as 2.76 × 10−6 mol% and gave high yields. The LbL catalyst and the technology presented in this work, show distinctive features that include extraordinarily low loading and high catalytic active characteristics.

A multilayer film (Pd2+/1)n was prepared with Pd(II) ions and platinum compound trans-[Pt(PPh3)2(CCPy)2] (1) using the layer-by-layer self-assembly method. The film loaded on the quartz slide could be capable of discharging high catalytic active Pd species to promote the C–C coupling reaction, with extraordinarily low Pd-loading (6.6 × 10−6 mol%) and high catalytic efficiency in H2O–EtOH solution.

The macroporous materials were prepared from the transformation of cuttlebone as biotemplates under hydrothermal reactions and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric/differential thermal analyses (TG-DTA), and scanning electron microscopy (SEM). Cell experimental results showed that the prepared materials as bone tissue engineering scaffolds or fillers had fine biocompatibility suitable for adhesion and proliferation of the hMSCs (human marrow mesenchymal stem cells). Histological analyses were carried out by implanting the scaffolds into a rabbit femur, where the bioresorption, degradation, and biological activity of the scaffolds were observed in the animal body. The prepared scaffolds kept the original three-dimensional frameworks with the ordered porous structures, which made for blood circulation, nutrition supply, and the cells implantation. The biotemplated syntheses could provide a new effective approach to prepare the bone tissue engineering scaffold materials.Keywords: biocompatibility; cuttlebones; hydrothermal; hydroxyapatites; macroporous materials; scaffolds;

Assembly reactions of 9,9-diethylfluorene-2,7-dicarboxylic acid (H2DFDC) and Mn(CH3COO)2·4H2O or MnCl2·4H2O by tuning of various secondary ligands such as 2,2′-bipyridine (2,2′-bpy), 4,4′-bipyridine (4,4′-bpy) or 1,3-bis(4-pyridyl)propane) (bpp), gave rise to four complexes {[Mn2(DFDC)2(DMF)2]·H2O}n (1), [Mn(DFDC)(2,2′-bpy)]n (2), {[Mn2(DFDC)2(4,4′-bpy)2]·2CH3OH}n (3), and {[Mn4(DFDC)4(bpp)2(CH3OH)3 (H2O)3]·3(CH3OH)·3(H2O)}n (4). Single crystal X-ray diffraction analysis reveal that complex 1 is three dimensional structure with rhombic channels filled by guest water molecules; 2 presents a close-packed structure with high thermal stability; 3 exhibits a three dimensional framework with micro-porous channels filled by guest methanol molecules and 4 is a two-dimensional structure. The photoluminescent properties of 1–4 have been studied, respectively, showing that the Mn(II) ions, accessorial organic ligands or crystal structures exert important influences on the photoluminescence emissions of H2DFDC ligands. Thermogravimetric analysis show that the complexes have remarkably high thermal stability. Magnetic susceptibility measurements have been finished and discussed for the complexes.Graphical abstractAssembly of 9,9-diethylfluorene-2,7-dicarboxylic acid and Mn(II) salts by tuning of various accessorial ligands resulted in four manganese complexes with different topological frameworks. Highlights► Four manganese complexes based on 9,9-diethylfluorene-2,7-dicarboxylic acid were obtained. ► The complexes were structurally characterized by single-crystal X-ray diffraction. ► The complexes 1–4 display different topological structures. ► Thermogravimetric analysis show the complexes have remarkably high thermal stability.

Reaction of 5-aminosalicylic acid with 2-pyridinecarboxaldehyde or sodium chloroacetate gave two new ligands 5-((pyridin-2-yl)methyleneamino)-2-hydroxybenzoic acid (HL1) and 5-(bis(carboxymethyl)amino)-2-hydroxybenzoic acid (H2L2), respectively. Two compounds [Co(L1)2(H2O)2]·2H2O (1) and [Cu2(L2)2(phen)2] (2) (phen = 1,10-phenanthroline) were synthesized and characterized by IR, PXRD, TGA and cyclic voltammetry. Single crystal X-ray diffraction analysis reveals that complex 1 is a mononuclear structure and the metal center is coordinated in an octahedral geometry. Complex 2 is a dinuclear structure, in which the Cu atom is in a square pyramidal geometry.

An alkynyl platinum(II) compound of [Pt(CCPy)2(dppe)] (1) was prepared by reaction of [PtCl2(dppe)] and 4-ethynylpyridine hydrochloride in the presence of base and CuI (dppe = 1,2-bis(diphenylphosphino)ethane). Single crystal X-ray diffraction analysis reveals that compound 1 crystallizes in a monoclinic system and Cc space group with a = 17.8507(7), b = 21.4219(7), c = 9.0526(5) Å, β = 108.98(2)°. Thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), UV-vis spectra, photoluminescence, and catalysis properties of 1 are discussed. The multilayer films formed with ruthenium trichloride by a layer-by-layer self-assembly method were characterized by UV-vis spectra, atomic force microscopy (AFM) images and cyclic voltammograms (CV).

Two new 2D metal–organic frameworks were assembled in different conditions. Single X-ray diffraction analyses reveal that complex 1 possesses packing of large helical channels filled by guest water molecules; and 2 has a 2-fold interpenetration layer-like structure with relatively petite helical channels, with guest water molecules residing in the void spaces between neighboring helical layers. The diverse structures may result from dissimilar crystal growth mechanisms with distinct thermal stable energies confirmed by theoretical calculation. Photoluminescent spectra, thermogravimetric analyses and power X-ray diffraction analyses were performed.

Assembly reactions of orotic acid (H3dtpc ) and CdCl2·2.5H2O or CdSO4·8H2O yielded four new cadmium compounds {[Cd(H2dtpc)(phen)(H2O)2]·(H2dtpc)·4H2O}2 (1: solution reaction, pH=4–5, in addition of phen), [Cd3(dtpc)2(phen)5]·13H2O (2: hydrothermal reaction, initial pH=14, final pH=7.5), [Cd(Hdtpc)(H2O)3]4 (3: solution reaction, initial pH=6.5, final pH=6.0), {[Cd(Hdtpc)(phen)(H2O)]·H2O}n (4: hydrothermal reaction, initial pH=8; final pH=6.5), respectively. Compounds 1–4 have been characterized by IR, thermogravimetric analyses (TGA), photoluminescence analyses, single-crystal and powder X-ray diffraction (PXRD). Compound 1 is a binuclear, 2 is a trinuclear, 3 is a tetranuclear structure, and 4 possesses one-dimensional chain framework, respectively, in which the orotate ligands show seven different linking fashions in 1–4. The orotate ligands as trivalence anions are observed in the formation of orotate-compounds, in which the orotates show high stability under the extreme condition of strong basic solution, high temperature and pressure.Graphical abstractAssembly of orotic acid and Cd(II) salts result in four new compounds under different reaction conditions, the compounds possess strong photoluminescence emissions and high thermal stability.Highlights► Four Cd-compounds were prepared from orotic acid under different crystallization systems. ► The orotates as trivalence anions displayed high stability under extremely conditions. ► The orotates displayed various connection modes in the compounds. ► The strong photoluminescence emissions have been observed in the compounds.

Assembly of orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H3dtpc) and Cd(OAc)2·2H2O gave rise to two complexes [Cd2(H2dtpc)2(H2O)6] (I) and [Cd(H2dtpc)(bpy)(H2O)]n (II) (bpy = 2,2′-bipyridine). Complex (I) and (II) have been characterized by X-ray single crystal diffraction, IR, PXRD, TGA and fluorescence spectra. Structural analyses reveal that (I) is a binuclear structure, and complex (II) possesses a one-dimensional infinite zig-zag chain architecture and the chains are further assembled into 2D supramolecular network by strong hydrogen bonding interactions. Crystal data for (I): Monoclinic, space group P2(1)/n, a = 9.3221(19) Å, b = 6.6315(13) Å, c = 15.322(3) Å, β = 102.31(3)°, V = 925.4(3) Å3, Z = 4, R1 = 0.0269, and wR2 = 0.0604; for (II): Monoclinic, space group P2(1)/c, a = 9.9880(2) Å, b = 14.5085(2) Å, c = 11.6957(2) Å, β = 107.976(2)°, V = 1612.10(5) Å3, Z = 4, R1 = 0.0234 and wR2 = 0.0554.

A novel coordination polymer, {[Eu2(L)3(CH3OH)(H2O)]·(CH3OH)(H2O)}n (1), has been synthesized by solvothermal reaction of Eu(NO3)3·6H2O and 9,9-diethylfluorene-2,7-dicarboxylic acid in a mixture solution of CH3OH and H2O. Single crystal X-ray structural analysis reveals that complex 1 crystallizes in an orthorhombic, space group P2(1)2(1)2(1), holding the unusual (2,3,8)-connected 3D topological network. Thermogravimetric analysis shows remarkable thermal stability of the structural framework of compound 1, the photoluminescence properties are also discussed.The novel 3D coordination polymers, {[Eu2(L)3(CH3OH)(H2O)]·(CH3OH)(H2O)}n (1), constructed from Eu(III) ions and 9,9-diethylfluorene-2,7-dicarboxylate with remarkable thermal stability and strong fluorescence emission in the solid state.

Four novel topological nets of lanthanide metal-organic frameworks: [Sm2(op)3(H2O)]n (1), {Ln2(op)2(ox)(H2O)4] · H2O}n (Ln = La, 2; Sm, 3), {[La2(mp)2(ox)(H2O)4] · 2H2O}n (4), [La2(op)2(mp)(H2O)4]n (5) (op = o-phthalate, mp = m-phthalate, and ox = oxalate), have been hydrothermally synthesized and characterized. Compound 1 exhibits novel (3,4,5,6)-connected five-nodal two-dimensional net, compound 2 and 3 show the (3,4)-connected V2O5 topologies, compound 4 has the (4,5)-connected topological net, and compound 5 shows the (4,5)-connected four-nodal three-dimensional network. Photoluminescent analyses of 1 and 3 show strong blue emission in the solid state at room temperature.Four novel topological nets of lanthanide frameworks have been hydrothermally synthesized. Compound 1 exhibits novel (3,4,5,6)-connected 2D five-nodal topological net, compounds 2 and 3 show (3,4)-connected V2O5 topologies, compound 4 displays the (4,5)-connected 3D topological net, and compound 5 shows the (4,5)-connected 3D four-nodal topological network.

The novel 3D coordination polymer, [Zn3(μ5-PTC)2(μ2-H2O)2]n (1), has been synthesized by hydrothermal reaction of ZnI2 · 4H2O with H3PTC and triethylamine (H3PTC = pyridine-2,4,6-tricarboxylatic acid). Single crystal X-ray structural analysis reveals that complex 1 crystallizes in an orthorhombic space group Pbcn, holding the unusual (5,6)-connected 3D topological network. Fluorescent measurement of 1 exhibits strong blue emission in the solid state at room temperature, and its framework shows remarkable thermal stability.The novel 3D coordination polymer, [Zn3(μ5-PTC)2(μ2-H2O)2] (1), displays the unusual (5,6)-connected topological network and strong blue fluorescence in the solid state at room temperature.

•BaLi2Ti6O14 nanofibers are prepared via electrospinning for the first time.•BaLi2Ti6O14 nanofibers show superior electrochemical performance.•0.153‰ capacity loss per cycle can be delivered at 1000 mA g−1.•Structural reversibility of BaLi2Ti6O14 nanofibers is studied by in-situ XRD.Ultralong BaLi2Ti6O14 nanofibers constructed from attached nanoparticles, as be an excellent candidate of long cycle life and good rate capability anode material of lithium-ion batteries for future applications in portable electronics, electric vehicles and grid storage, are prepared through electrospinning and subsequent annealing. The obtained materials are characterized by powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry and in situ X-ray diffraction. The unique one-dimensional nanomaterials used as an anode of lithium-ion batteries exhibit superior electrochemical performances: (i) excellent rate behavior (The charge capacities are 133.7, 127.2, 122.5, 119.1, 116.0 and 113.8 mAh g−1 at 100, 200, 300, 400, 500 and 600 mA g−1 separately); (ii) outstanding cycle performance (When the nanomaterials are cycled at 200, 500 and 1000 mA g−1 respectively, the initial charge capacities of 138.2, 137.3 and 140.2 mAh g−1 fade with the corresponding average rate of 0.528‰, 0.197‰ and 0.153‰ per cycle until the 200th, 400th and 800th cycles). The results above reveal the great potential of the BaLi2Ti6O14 nanofibers as a practical anode for high performance lithium ion batteries.Download high-res image (220KB)Download full-size image

The platinum complex [Pt2(CCPy)2(dppm)2] (Py = 4-pyridyl, dppm = bis(diphenylphosphino)methane) 1 has been prepared and characterized. Single crystal X-ray diffraction analysis reveals that the Pt2(CCPy)2 fragment of 1 exhibits an approximately linear molecular geometry, in which the Pt–Pt bond may be considered as having been inserted within the delocalized π-electron system of the 1,4-bis(4′-pyridyl)buta-1,3-diyne. The ability of the two terminal pyridyl nitrogen atoms of 1 to coordinate to other metal centers has enabled the use of 1 as a linking ligand in the layer-by-layer (LbL) growth of heterometallic films. The self-assembly behavior of 1 with Pd(II), supported by chloride counter ions, on poly(ethylenimine) (PEI) functionalized solid surfaces has been investigated. The resulting multilayer films of general composition and form (PdCl2/1)n have been characterized using UV-vis absorption spectroscopy, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). On the basis of the UV-vis spectroscopic data, it was shown that the (PdCl2/1)n multilayer films could be grown in a regular fashion, with film thickness increasing linearly with increasing deposition of the metal–ligand bilayers. Consistent with this metal ion dependent LbL growth, AFM images of the multilayer films exhibited island-shaped nanostructures with a mean diameter of about 25 nm. The catalytic properties of the (PdCl2/1)n multilayers were investigated, and (PdCl2/1)n film-loaded slides were used as a catalyst reservoir capable of liberating catalytic amounts of a highly active Pd species, which was suitable for promoting C–C bond formations. The catalyst loading was as low as 2.76 × 10−6 mol% and gave high yields. The LbL catalyst and the technology presented in this work, show distinctive features that include extraordinarily low loading and high catalytic active characteristics.

A multilayer film (Pd2+/1)n was prepared with Pd(II) ions and platinum compound trans-[Pt(PPh3)2(CCPy)2] (1) using the layer-by-layer self-assembly method. The film loaded on the quartz slide could be capable of discharging high catalytic active Pd species to promote the C–C coupling reaction, with extraordinarily low Pd-loading (6.6 × 10−6 mol%) and high catalytic efficiency in H2O–EtOH solution.

Gold nanoparticles (AuNPs) modified by 8-hydroxy-quinoline (8-HQ) and stabilized by polyvinylpyrrolidone (PVP) were used for highly selective and sensitive colorimetric detection of Hg2+ based on the quick aggregation of AuNPs leading to a color change from wine red to gray. The limit of Hg2+ detection in real environmental water samples is 4.0 × 10−7 M by the naked eyes and 1.0 × 10−8 M by UV-vis spectroscopy.