Polyaniline Microtubes with a Hexagonal Cross‐Section and pH‐Sensitive Fluorescence Properties

Polyaniline (PANI) microtubes with a hexagonal cross‐section are successfully synthesized by a self‐assembly process in the presence of 8‐hydroxyquinoline‐5‐sulfonic acid (HQS) as a dopant and FeCl₃ as an oxidant. The wall thickness of the PANI/HQS microtubes can be adjusted by the content of the oxidant. It is proposed that the aniline/HQS salts serve as a hard template for the formation of the hexagonal‐cross‐section microtubes. Moreover, PANI/HQS microtubes combined with ZnSO₄ show pH‐dependent fluorescence. PANI hexagonal‐cross‐section microtubes combined with a pH‐sensitive fluorescence may promise potential applications in fields such as chemical sensors and confined reaction vessels.

     

铁酸钴纳米微粒的共沉淀法制备和磁性质(英)

The cobalt ferrite nanoparticles were prepared by coprecipitation in the presence of poly (N-vinylpyrrolidone) (PVP) and characterized by XRD, TEM, EDX and magnetometry. XRD results suggest the formation of pure cobalt ferrite. The mean particle sizes of CoFe₂O₄ samples annealed at 400 ℃ and 600 ℃ were ca. 6 and 25 nm, respectively as obtained by transmission electron microscopy (TEM). The magnetic measurements indicated that nano-particles obtained at 400 ℃ were superparamagnetic while that prepared at 600 ℃ were ferrimagnetic.     

以滤纸为模板合成新型介孔生物活性玻璃微管材料

用快速滤纸为生物模板,通过先浸渍后焙烧的方法合成了介孔生物活性玻璃微管材料。快速滤纸的管状结构被完美复制,其管壁为生成的介孔生物玻璃材料。通过在合成过程中引入铁元素可以使材料具有一定的磁性。材料的形貌、结构和磁性通过扫描电镜、粉末X射线衍射、透射电镜、氮气吸附-脱附曲线,红外光谱和磁滞回线进行了表征。并且通过模拟体液浸泡方法考察了其矿化能力,以地塞米松为模型药物考察其释药能力和生物相容性。合成的介孔生物活性玻璃微管材料具有复杂的管状多级结构、快速的矿化能力和良好的生物相容性,并具备一定的磁性,是一种不可多得的药物缓释材料。     

以滤纸为模板合成新型介孔生物活性玻璃微管材料

用快速滤纸为生物模板,通过先浸渍后焙烧的方法合成了介孔生物活性玻璃微管材料。快速滤纸的管状结构被完美复制,其管壁为生成的介孔生物玻璃材料。通过在合成过程中引入铁元素可以使材料具有一定的磁性。材料的形貌、结构和磁性通过扫描电镜、粉末X射线衍射、透射电镜、氮气吸附-脱附曲线,红外光谱和磁滞回线进行了表征。并且通过模拟体液浸泡方法考察了其矿化能力,以地塞米松为模型药物考察其释药能力和生物相容性。合成的介孔生物活性玻璃微管材料具有复杂的管状多级结构、快速的矿化能力和良好的生物相容性,并具备一定的磁性,是一种不可多得的药物缓释材料。     

Hydrothermal Synthesis,Crystal Structure and Magnetic Properties of a Cobalt(II) Coordination Polymer Assembled by 4-Sulfophthalate and 4,4'-Bipyridine

1 INTRUDUCTION The rational design and synthesis of metal-direc- ted supramolecular framework have received much attention in coordination chemistry because of their potential applications in catalysis, molecular selec- tion, non-linear optics, ion exchange and microelec- tronics[1～4]. During the lastdecade, many high-di- mensional coordination complexes have been de- signed and prepared through molecular self-as- sembly process[5～10]. The construction of open metal organic framework, s…     

基于分子的六氰合铁酸钴纳米粒子：合成，表征及其电化学性质

采用直接混合法制得平均尺寸小于50 nm的六氰合铁酸钴纳米粒子，元素分析表明其计量学分子式为K_0.2Co_1.4[Fe(CN)₆]•xH₂O，红外光谱证明此物质是由铁磁性的Co^II_1.5[Fe^III(CN)₆]和反铁磁性的KCo^III[Fe^II(CN)₆]组成，并含有一定量的结晶水。用六氰合铁酸钴纳米粒子修饰的玻碳电极具有良好的稳定性和可逆的循环伏安行为，其电化学特征受溶液中配对阳离子种类和支持电解质浓度的影响。作为电极表面的媒介体，该薄膜对多巴胺的氧化还原具有电催化作用。     

Hierarchical Hollow Co9S8 Microspheres: Solvothermal Synthesis,Magnetic, Electrochemical,and Electrocatalytic Properties

A simple solvothermal route in a binary solution of triethylenetetramine (TETA) and deionized water (DIW) has been used to synthesize hierarchical hollow Co₉S₈ microspheres with high surface area (80.38 m² g^?1). An appropriate volume ratio of TETA:DIW has been found to be essential for the formation of hollow Co₉S₈ microspheres. The magnetic study indicated that the Co₉S₈ hollow microspheres are paramagnetic at high temperature and antiferromagnetic at low temperature. The oxygen reduction reaction experiments demonstrated that the onset potential of the Co₉S₈ sample is 0.88 V, which is comparable to the value predicted for Co₉S₈ (0.74 V) from the theoretical simulation. The discharge capability of Co₉S₈ hollow microspheres as cathode materials for lithium ion batteries and their electrocatalytic activity for the oxygen reduction reaction (ORR) have been studied.     

Template‐Free Synthesis of Nanorod‐Assembled Hierarchical Zn1−xMnxS Hollow Nanostructures with Enhanced Pseudocapacitive Properties

Mixed‐metal sulfide Zn_1?xMn_xS nanorod‐assembled hierarchical hollow spheres were synthesized by a template‐free solvothermal process based on Ostwald ripening. In the reaction system, glycerol plays a key role in the formation of Zn_xMn_1?xS hierarchical hollow structures by a quasi‐microemulsion‐template mechanism. When applied as capacitor electrode material, the hierarchical Zn_1?xMn_xS hollow spheres show excellent electrochemical performance. Specifically, Zn_0.25Mn_0.75S hollow spheres can deliver a high specific capacitance of 664 F g^?1 at a current rate of 1 A g^?1, which is almost five times of that of MnS under the same conditions and higher than those of previously reported single Mn‐based compounds.     

Enhanced Electrochemical Capacitive Properties of Nickel‐Cobalt Oxide Nano‐flakes Materials

Nickel‐cobalt oxide nano‐flakes materials are successfully synthesized by a facile chemical co‐precipitation method followed by a simple calcination process. The studies show that the as‐prepared nickel‐cobalt oxides with different Ni/Co ratio are composed of NiO and Co₃O₄ compounds. The Co_0.56Ni_0.44 oxide material, which exhibits a mesoporous structure with a narrow distribution of pore size from 2 to 7 nm, possesses markedly enhanced charge‐discharge properties at high current density compared with the pure NiO and pure Co₃O₄. The Co_0.56Ni_0.44 oxide electrode shows a specific capacitance value of 1227 F/g at 5 mA/cm², which is nearly three times greater than that of the pure NiO electrode at the same current density.     

Surfactant‐Assisted Phase‐Selective Synthesis of New Cobalt MOFs and Their Efficient Electrocatalytic Hydrogen Evolution Reaction

Reported herein are two new polymorphic Co‐MOFs (CTGU‐5 and ‐6) that can be selectively crystallized into the pure 2D or 3D net using an anionic or neutral surfactant, respectively. Each polymorph contains a H₂O molecule, but differs dramatically in its bonding to the framework, which in turn affects the crystal structure and electrocatalytic performance for hydrogen evolution reaction (HER). Both experimental and computational studies find that 2D CTGU‐5 which has coordinates water and more open access to the cobalt site has higher electrocatalytic activity than CTGU‐6 with the lattice water. The integration with co‐catalysts, such as acetylene black (AB) leads to a composite material, AB&CTGU‐5 (1:4) with very efficient HER catalytic properties among reported MOFs. It exhibits superior HER properties including a very positive onset potential of 18 mV, low Tafel slope of 45 mV dec⁻¹, higher exchange current density of 8.6×10⁻⁴ A cm⁻², and long‐term stability.     

Novel Cobalt (II) Phthalocyanine‐Containing Polyimides: Synthesis,Characterization, Thermal and Optical Properties

Summary: A novel class of polymer has been prepared by reaction of a copolyimide containing carboxylic acid groups, and a cobalt phthalocyanine peripherally substituted with a reactive hydroxyl group. The incorporation of the phthalocyanine ring was achieved by esterification of the carboxylic acid groups of the polyimide with the free hydroxyl group of the phthalocyanine. In this work, a limited number of phthalocyanine rings have been introduced in order to avoid extensive modification of the copolyimide properties. The extent of modification (percentage of esterified carboxylic groups) was estimated to be about 18%. The resulting material showed good thermal stability and a high glass transition temperature (above 300 °C). The incorporation of the bulky phthalocyanine ring brought about a light decrease of thermal properties, relative to those of the initial polyimide. The presence of phthalocyanine was confirmed by the absorption band at 670 nm showing in the visible region for the modified polyimide. The novel copolyimide also exhibited a remarkable emission peak at 430 nm, when excited at 350 nm, corresponding to the emission of the cobalt phthalocyanine moiety.

Schematic representation of the PI‐CoPc molecule and the chemical structure of the repeat unit.     

两个由异烟酰胺构筑的钴、镍配合物的合成及晶体结构

采用溶液培养法,在室温下合成了2个新的过渡金属配合物[Co(inta)2(H2O)4][Co(H2O)6](tdc)2.2H2O(1)和[Ni(inta)2(H2O)4](tdc).2H2O(2)(inta=异烟酰胺,H2tdc=2,5-噻吩二甲酸)。并对其进行了元素分析、红外光谱、紫外光谱、热重和X-射线单晶衍射测定。这两个配合物通过氢键和π-π相互作用形成了三维超分子网状结构。     

Chirality‐ and pH‐Controlled Supramolecular Isomerism in Cobalt Phosphonates and Its Impact on the Magnetic Behavior

Two pairs of enantiomeric compounds with formulas (S)‐ or (R)‐Co₃(ppap)₂(4,4′‐bpy)₂(H₂O)₂ ? 4 H₂O [(S)‐ 1 or (R)‐ 1 ], (S)‐ or (R)‐Co₃(ppap)₂(4,4′‐bpy)₂(H₂O)₂ ? 3 H₂O [(S)‐ or (R)‐ 2 ), and related racemic compound Co₃(ppap)₂(4,4′‐bpy)₂(H₂O)₂ ? 4 H₂O (rac‐ 3 ; 4,4′‐bpy=4,4′‐bipyridine, H₃ppap=3‐phenyl‐2‐[(phosphonomethyl)amino]propanoic acid) are reported. Compounds 1 and rac‐ 3 show identical three‐dimensional framework structures, whereas compounds 2 have two‐dimensional layer structures. Compounds 1 and 2 are catenation isomers, formation of which is controlled solely by the pH of the reaction mixtures, whereas the formation of isomeric compounds 1 and rac‐ 3 is controlled purely by the chirality of the phosphonate ligand. The magnetic properties of fully dehydrated (S)‐ 1 , (S)‐ 2 , and rac‐ 3 are highly dependent on both structure and chirality.