A novel 3D Co(II) coordination polymer with a considerable 2D channel: Synthesis,topological structure,magnetic and electrochemical properties

A novel 3D Co(II) complex [Co(Hhmt)(H₂O)∙H₂O] (1) (H₃hmt = 3,5-bis (hydroxymethyl)-1,2,4-triazole) has been hydrothermally synthesized. X-ray single crystal diffraction experiment reveals that each Hhmt^2 − ligand connects three Co(II) ions to form a 3D lvt topological framework with the (4² ∙ 8⁴) point symbol, especially for the existence of a considerable 2D channel. The magnetic and electrochemical properties of 1 are also discussed.     

Polyaniline with high crystallinity degree: Synthesis,structure, and electrochemical properties

Polyaniline (PANI) with high crystallinity degree was facilely synthesized on the surface of stainless steel net by galvanostatic method. The effect of polymerization current density on the characteristics of morphology and structure had been investigated by field emission scanning electron microscopy (FE‐SEM), Fourier transforms infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). FE‐SEM observations disclosed that PANI was deposited as nanofibers and their diameters decreased with the polymerization current density. FTIR studies revealed that degree of oxidation increased in order PANI‐2 < PANI‐6 < PANI‐10. XPS measurements displayed that PANI polymerized at 6 mA cm^?2 (PANI‐6) exhibited much higher doping level of 77.8%, which favored the conductivity. XRD analysis discovered that the obtained PANI showed high crystallinity degree in which PANI‐6 possessed highest crystallinity degree (X_cr) up to 67%. Electrochemical performances of PANI as electrode materials were studied via cyclic voltammetry. The results presented that PANI‐6 possessed greater discharge capacity and better reversibility. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40827.     

One-dimensional helical Cu(II) coordination polymer: Synthesis,structures, and properties

One new Cu(II) coordination polymer (1) based on 6,6′-dihydroxy-2,2′-bipyridine (H₂dhbp) was successfully prepared, with the formula of [Cu(μ₂-OH)(Hdhbp)]_n (1). Single-crystal X-ray analysis shows that compound 1 crystallizes in orthorhombic chiral space group P2₁2₁2₁ and exhibits a left-handed (L) helical [Cu(μ₂-OH)]_n-chain. Luminescence of 1 exhibits a broad emission around 440 nm, attributing to the metal to ligand charge transfer (MLCT). Magnetic susceptibility shows antiferromagnetic coupling within compound 1. Cyclic voltammetry (CV) experiments indicate a potential water oxidation electrocatalyst.     

Synthesis,X-ray structure,spectroscopic properties,and theoretical investigations of dinuclear imidazole molybdenum(VI) complex with long MoO bands

One new dinuclear multioxomolybdenum(VI) complex containing long MoO bands with imidazole, [Mo₂O₆(imi)₄] (1) (imi = imidazole), has been prepared and characterized, and the geometric structure, electronic structure and spectroscopic properties, investigated experimentally and theoretically. The rarely observed long MoO bonds in 1 (ca. 0.15 Å longer than documents previously) are analysed by orbital structure analysis. The electronic origins of the optical transitions are also mainly related to the MoO groups with ligand-to-metal charge transfer (LMCT) nature (P_terminal-oxo → d_Mo).     

Synthesis,structure and electrochemical properties of the cationic complex tris-(imidazolidine-1,10-phenanthroline)iron(II)

The complex [Fe^II(Imz-phen)₃](PF₆)₂, (Imz-phen = imidazolidine-[4,5-f]-1,10-phenanthroline) has been prepared and characterized using X-ray diffraction, UV–vis and IR spectroscopy, elemental analysis, fast atomic bombardment (FAB) mass spectrometry, and cyclic voltammetry. Its crystal lattice includes acetonitrile (π–π bound to phenanthroline), methanol, and water molecules. Scanning continuously between 1000 mV and 1650 mV in CH₃CN, a modified electrode that includes the iron (II) complex is obtained; after the 25th continuous cycle a stable film is formed that is electrocatalytically active in the reduction of sulfur oxoanions. When the electrocatalytic properties are evaluated in ethanol/water solution, the current achieved from the electroreduction of these sulfur species is linearly dependent on the respective concentrations, suggesting potential application in sulfite determination.     

A three-dimensional highly stable Zn(II) coordination polymer based on 1,4-benzeneditetrazolate (H2BDT): Synthesis,crystal structure,and luminescent properties

1,4-benzeneditetrazolate [H₂BDT] (1) and its 3D coordination polymer [Zn(BDT)]_n (2), have been synthesized and structurally characterized by infrared spectroscopy (IR), thermal gravimetric analysis (TG), and single-crystal/powder X-ray diffraction. The result of the single-crystal X-ray diffraction analysis indicates that 1 is a 3D supramolecular structure stabilized by intermolecular hydrogen bonds and π…π stacking interactions. 2 is a 3D (4,4)-connected coordination polymer with the central metal Zn(II) ions linked together by BDT^2? anions. Photoluminescent measurement for 2 in the solid state elucidates that 2 displays a strong photoluminescence at 469 nm, which suggests that 2 may be a potential blue-light material.     

A 2D helical coordination polymer based on Keggin-type polyoxoanion: Synthesis,crystal structure and luminescent properties

A novel two-dimensional helical coordination polymer [Ag(CH₃CN)₄][Ag₃(CH₃CN)₈(SiMo₁₂O₄₀)] (1) has been gained by the conventional self-assembly reaction, and characterized by IR, elemental analysis, UV, TG technique and X-ray single crystal diffraction. Each [SiMo₁₂O₄₀]^4? cluster interconnects with three bimetallic cation subunits through three Mo–O–Ag bridges, meanwhile, each bimetallic cation subunit is surrounded by three [SiMo₁₂O₄₀]^4? to form an unprecedented two-dimensional network structure. The metal–metal bonds between Ag(1) and Ag(2) atoms from the adjacent helical chains connects the chains together into a chiral 2D helical network. The 2D network structures are further interconnected with each other to form a 3D supramolecular network through multiform intermolecular hydrogen bonds. The luminescent properties of the coordination polymer in the solid state were investigated.     

A novel cobalt(II) acylpyrazolonate complex with intermolecular hydrogen bond: Synthesis,structure and properties

A new cobalt complex, [Co(L)₂·(H₂O)₂](HL = 4-hexanoyl-3-methyl-1-phenyl-1H -pyrazol-5(4H)-one), was synthesized by us. The complex was characterized by single crystal X-ray diffraction, IR, UV, fluorescence spectra and thermogravimetric analysis. The results of characterization showed that the crystal is monoclinic system with crystal parameters: a = 15.2439(12) Å, b = 7.4101(6) Å, c = 15.7381(18) Å, and Z = 2, S = 1.074. It was found that the Co²⁺ is located in the inversion center of the complex. The Co(II) had an ideal octahedral coordination environment with four oxygen atoms of HL ligands in the equatorial plane and two water molecules in axial positions. The complex exhibits yellow emission as the result of the fluorescence from the intraligand emission excited state.     

Branched poly(p‐phenylenevinylene): Synthesis,optical and electrochemical properties

A series of poly(p‐phenylene vinylene) (PPV) derivatives with phenylene vinylene side chains (branched PPVs), PPV0, PPV1, PPV2, and PPV3, were synthesized by the Heck coupling reaction and characterized by TGA, absorption spectra, photoluminescence (PL) spectra, and electrochemical cyclic voltammetry. The branched PPVs showed two absorption peaks in the UV–vis region, corresponding to the conjugated side chains (UV absorption) and the main chains (the visible absorption). Especially the absorption spectrum of PPV3 covers a broad wavelength range from 300 to 500 nm. Introducing the electron‐donating alkoxy substituents on the PPV main chains and increasing the content of the alkoxy groups lead to bathochromic shift of both absorption and PL spectra from PPV1 to PPV2 to PPV3. The onset oxidation potential of the branched PPVs is lower by 0.1–0.2 V than that of PPV, indicating that the electron‐donating ability of the branched PPVs enhanced in comparison with that of PPV. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis,structure and electrochemical properties of tris (2-(2-pyridyl)-4-methylcarbonylquinoline) ruthenium(II) hexafluorophosphate

A novel ruthenium complex with 2-(2-pyridyl)-4-methylcarbonylquinoline ligand has been prepared and characterized: the first crystal structure of such complex along with its physical and chemical properties are also described.     

Synthesis and characterization of poly(N-propargylurea)s with helical conformation,optical activity and fluorescence properties

This article presents novel N-propargylurea-based copolymers that contain both carbazole and urea moieties in their side chains. The homopolymer of monomer 1 with a carbazole group exhibited interesting fluorescence properties, while the homopolymer of monomer 2 with a chiral center formed helical structures. The copolymerizations of monomers 1 and 2 provided optically active helical copolymers, which had fluorescence properties, even for the copolymer that contained as low as 20 mol% of monomer unit 1. Fluorescent and optically active composite films were further prepared based on the copolymers and with poly(vinyl butyl) as the supporting material. This study contributes to the intriguing research field of optically active helical polymers and their practical applications.     

Carbon nanofibers: Synthesis, characterization, and electrochemical properties

Carbon nanofibers (CNFs) have been synthesized by co-catalyst deoxidization process by a reaction between C₂H₅OC₂H₅, Zn and Fe powder at 650 °C for 10 h. These nanofibers exhibit diameters of ∼80 nm and lengths ranging from several micrometers to tens of micrometers. X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy indicate that as-prepared CNFs possess low graphitic crystallinity. The resultant CNFs as electrode shows capacity of ∼220 mAh/g and high reversibility with little hysteresis in the insertion/deintercalation reactions of lithium-ion. In addition, the possible growth of CNFs is discussed.     

pH Dependent formations of dinuclear molybdenum(V) and incomplete cubane molybdenum(IV) complexes with nitrilotriacetate

Nitrilotriacetato oxomolybdenum(V) dinuclear complex (NH₄)₄[cis-Mo₂O₄(nta)₂] · 7H₂O (1) (H₃nta = nitrilotriacetic acid) and its incomplete cubane-type trinuclear molybdenum(IV) complex [Mo₃O(OH)₃(Hnta)₃] · Cl · 3H₂O (2) are isolated in a weak acidic and an acidic solutions, respectively (pH 4.5 and 1.0). The nitrilotriacetate ligand in the anion 1 or the cation 2 displays tridentate mode through the nitrogen atom and the oxygen atoms of β-carboxy groups. Unusual protonations of bridged oxygen atoms in 2 have not effect on the skeleton of molybdenum(IV) cap Mo₃O unit. There are obvious dissociations of molybdenum(V) complexes based on ¹³C NMR observations in solution.     

The relationship of structure to properties in surfactants: V. Synthesis and properties of α,ω-bis (sodium p-sulfophenoxy)alkanes

A series of symmetrical surfactants containing two arylsulfonate groups in the molecule, of general structure, where n=4, 6, 8, 10 and 12, has been synthesized. The synthesis involves sulfonation of the corresponding diaryl ethers, isolation, purification, and characterization of the free para-disulfonic acids, followed by conversion of the latter to the disodium salts. The nuclear magnetic resonance (NMR) spectra of the products indicate that they are the para-sulfonated compounds substantially free of the ortho isomers. The Krafft points, surface tension-log concentration curves, critical micelle concentrations, and areas/molecule at the liquid/air interface have been determined. The surface area/molecule indicate that these compounds are lying flat in the liquid/air interface.     

Two 3D coordination complexes containing metal-triazolate helical chains: Synthesis,structure, fluorescence and NLO properties

Two three-dimensional coordinationcomplexes containing metal-triazolate helical chains wereobtained. Their fluorescent andnonlinear optical properties were explored.

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Synthesis,structure and electrochemical properties of Al doped high entropy perovskite Lix(LiLaCaSrBa)Ti1-xAlxO3

In this work, the Al doped high entropy perovskite Li_0.2La_0.2Ca_0.2Sr_0.2Ba_0.2TiO₃ ceramic is synthesized by using a solid state reaction method, and the effect of different doping amount on the crystal structures and conductivity are also studied. The result proves that doping leads to a positive influence on the conductivity of ceramic. The material of Li_0.1(LiLaCaSrBa)Ti_0.9Al_0.1O₃ (LLCSBTA-0.1) exhibits a high total conductivity with approximately 3.92 × 10^-7 S cm^-1 at 30 °C and an activation energy of 0.39 eV. The beneficial result can be ascribed to the increase of Li ⁺ concentration. The Li_0.2La_0.2Ca_0.2Sr_0.2Ba_0.2TiO₃ presents a pure cubic perovskite structure, but with partial tetragonal structure due to the addition of Al₂O₃. However, these high entropy perovskite ceramics showed porous structures which are unfavourable for lithium ion conduction. The electrochemical property of the Li_0.1(LiLaCaSrBa)Ti_0.9Al_0.1O₃ as electrode is investigated as well. The results show that the Li_0.1(LiLaCaSrBa)Ti_0.9Al_0.1O₃ electrode exhibits good cyclability and stability for the insert-extraction of lithium ions with the specific capacity of 58.6 mA h g^?1.     

亚磷酸三(2,4-二叔丁基苯基)酯的合成及其晶体结构

由2,4-二叔丁基酚与PCl3在二甲苯溶剂中反应合成了亚磷酸三(2,4-二叔丁基苯基)酯,其分子式为C42H63O3P.通过Nonius CAD4型X-射线衍射仪检测,其晶体结构测定结果如下:该晶体属于三斜晶系,P-1空间群,a=1.329 9(3)nm,b=1.350 3(3)nm,c=1.385 2(3)nm,α=112.20(3)°,β=104.66(3)°,γ=102.31(3)°,Dc=1.027 g/cm3,Z=2,F(000)=708,μ=0.098 mm-1,最终偏差因子分别为R=0.096 5,wR=0.245 0.X-射线衍射分析表明,分子内部分相邻原子间形成C—H…O氢键.     

Synthesis,optical, electrochemical,and thermal stability properties of poly(azomethine-urethane)s

In this study, the novel low band gap and thermally stable poly(azomethine-urethane)s (PAMUs) were synthesized to investigate aliphatic and aromatic group effects on some physical properties such as thermal stability, optical and electrochemical properties. For this reason, we firstly synthesized the new Schiff bases via condensation reaction of 5-nitrovanilin with aromatic and aliphatic diamines. Then, these monomers were converted to PAMUs derivatives by the step-polymerization reaction with aromatic and aliphatic diisocyanates. The structures of the compounds were confirmed by FT-IR, UV–vis, ¹H NMR, and ¹³C NMR techniques. The molecular weight distribution parameters of the compounds were determined by the size exclusion chromatography (SEC). The compounds were also characterized by solubility tests, TG–DTA, and DSC techniques. Cyclic voltammetry (CV) measurements were carried out and HOMO–LUMO energy levels and electrochemical band gaps (E^′g${E^{\prime }}_g$) were calculated from their absorption edges. Additionally, optical band gaps (E_g) were determined by using UV–vis spectra of the materials. Fluorescence measurements were carried out in THF, DMF, and DMSO solutions to determine the optimum concentrations and the maximal emission and excitation intensities.     

A spin-crossover catecholato–iron(III) system: Synthesis,crystal structure and magnetic properties

A new mononuclear Fe(III)–catecholate complex, which exhibits an incomplete spin transition without hysteresis, had been synthesized and structurally characterized. Analyzed from the structural characteristics, the tripodal ligand must play the important role in affecting the spin crossover (SCO) behavior. The larger steric strain effect and weak cooperativity existed in the crystal lattice are inclined to favor the incomplete transition.     

Synthesis,structure, and properties of poly(styrene-co-pentabromobenzyl acrylate) materials

Polymers and copolymers of pentabromobenzyl acrylate (PBBA) with styrene were syn-thesized and characterized. Poly(PBBA) exhibits a rather high glass transition temperature (T_g) and good solvent resistance. The incorporation of PBBA moiety into polystyrene (PSt) enhances T_g, improves the thermal stability, and also does not adversely affect polystyrene's mechanical properties. Copolymers prepared through both emulsion semibatch and batch processes exhibit random chain structures and possess similar properties such as T_g, inherent viscosity, and mechanical properties. Blends of poly(PBBA) and PSt demonstrate immiscible phase behavior, however their thermal stabilities are similar to the copolymers' stability at the same PBBA content. It is thus shown that the thermal stability of the systems investigated in this work is essentially affected by composition, regardless of the distribution and dispersion of the PBBA polymer or copolymers. © 1996 John Wiley & Sons, Inc.