Imidazole Coordinated Sandwich‐type Antimony Poly‐oxotungstates Na9[{Na(H2O)2}3{M(C3H4N2)}3(SbW9O33)2]·xH2O (M=NiII,CoII, ZnII,MnII)

The imidazole covalently coordinated sandwich‐type heteropolytungstates Na₉[{Na(H₂O)₂}₃{M(C₃H₄N₂)}₃‐ (SbW₉O₃₃)₂]·xH₂O (M=Ni^II, x=32; M=Co^II, x=32; M=Zn^II, x=33; M=Mn^II, x=34) were obtained by the reaction of Na₂WO₄·2H₂O, SbCl₃·6H₂O, NiCl₂·6H₂O [MnSO₄·H₂O, Co(NO₃)₂·6H₂O, ZnSO₄·7H₂O] and imidazole at pH≈7.5. The structure of Na₉[{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃(SbW₉O₃₃)₂]·32H₂O was determined by single crystal X‐ray diffraction. Polyanion [{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃(SbW₉O₃₃)₂}₃]^9? has approximate C_3v symmetry, imidazole coordinated six‐nuclear cluster [{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃]⁹⁺ is encapsulated between two (α‐SbW₉O₃₃)^9?, the three rings of imidazole in the polyanion are perpendicular to the horizontal plane formed by six metals (Na‐Ni‐Na‐Ni‐Na‐Ni) in the central belt, and π‐stacking interactions exist between imidazoles of neighboring polyanions with dihedral angel of 60°. The compounds were also characterized by IR, UV‐Vis spectra, TG and DSC, and the thermal decomposition mechanism of the four compounds was suggested by TG curves.     

A 3-D Metal-organic Framework Mn(Ⅱ)Complex with Ant Net Constructed from 3-Pyridin-4-yl-benzoic Acid

A new coordination polymer, [Mn(3,4-pybz)2]n·3(H2O)(1), has been hydrothermally synthesized from Mn Cl2·4H2O and an unsymmetrical 3-pyridin-4-yl-benzoic acid(3,4-Hpybz), and characterized by IR, elemental analysis, thermogravimetric analysis, and singlecrystal X-ray diffraction. In complex 1, each 3,4-pybz ligand represents a three-connected node to combine with the six-connected Mn(II) ions, generating a 3D binodal(3,6)-connected ant network. In addition, magnetic investigations reveal that complex 1 exhibits an antiferromagnetic behavior. According to the crystal structure, the full-geometrical optimization of complex 1 was carried out by using hybrid DFT methods at the B3LYP/6-31G(d) level. Meantime, the DFT-BS approach was applied to study the magnetic coupling behavior for complex 1, and the result reveals that the calculated exchange coupling constants J were in good agreement with the experimental data.     

Dielectric and magnetic properties of multiferroic BiFeO3 ceramics sintered with the powders prepared by hydrothermal method

BiFeO₃ ceramics were sintered in the temperature range of 700–900 °C by using the pure BiFeO₃ powders hydrothermally synthesized at 250 °C. The low reaction temperature and low sintering temperature prevent the element volatilization and phase decomposition. The ceramics sintered at 800 and 850 °C exhibit much dense microstructure with clear grains and grain boundaries. They also show high dielectric constant, dielectric dispersion and low loss tangent. At room temperature, the dielectric behaviors of BiFeO₃ ceramics are mainly attributed to the transition of localized charge carriers and the microstructure of grains and grain boundaries. The temperature dependence of dielectric constant and loss tangent confirms that the localized charge carriers are a main contribution to the dielectric permittivity. Activation energy E_α of relaxation process for the BiFeO₃ ceramic sintered at 850 °C is 0.397 eV. The obtained BiFeO₃ ceramics show magnetic responses, which are relative to the grain size.     

一种用于检测四环素和对硝基苯酚的高稳定性镉(Ⅱ)金属有机骨架

采用水-溶剂热法合成了 1例金属有机骨架(MOF)：{[Cd(L)_0.5(4，4''-bpy)_0.5]·H₂O}_n (1)，其中 H₄L=(1，1''∶4''，1″-三联苯)-2，2″，4，4″-四羧酸，4，4''-bpy=4，4''-联吡啶)。通过单晶 X射线衍射、元素分析、粉末 X射线衍射、热重分析以及红外光谱分析对配合物1的结构进行了表征。单晶结构分析表明1为三维结构，属于单斜晶系，C2/c空间群，Cd(Ⅱ)连接L^4-和4，4''-bpy形成二维平面结构，层与层之间通过 L^4-连接，构筑成了三维网状结构。该 MOF表现出良好的稳定性并且可以通过荧光猝灭法检测四环素(TET)和对硝基苯酚(4-NP)，四环素和对硝基苯酚的检出限分别为0.15和0.062 μmol·L^-1。此外，还研究了其荧光猝灭机理。1可成功应用于延河水样中TET和4-NP含量的测定。     

Biomimetic Self-Cleaning Anisotropic Solid Slippery Surface with Excellent Stability and Restoration

Anisotropic slippery surfaces are widely used in anti-fouling, smart control of liquid movement and directional liquid transportation. However, anisotropic slippery liquid-infused porous surfaces (SLIPS) cannot meet the need of practical applications owing to loss and contamination of liquid lubricants. Inspired by solid epicuticular wax on the surface of land plant leaves, we herein report a type of biomimetic anisotropic solid slippery surface (ASSS) based on paraffin wax-incorporated paper with directional micro-grooves. This ASSS material shows anisotropic sliding behavior for liquid droplets with different surface tensions. It is demonstrated to be of excellent stability compared with SLIPS as the solid lubricant cannot be lost and stain the contacting surfaces. It also exhibits outstanding acid and alkali corrosion resistance and restoration capability upon physical damage. Both hydrophilic and hydrophobic contaminants on our ASSS can be self-cleaned by using only water droplets. Our ASSS extends the fabrication of new slippery materials and overcomes some drawbacks of SLIPS.     

Characterization of three new divalent zinc coordination polymers involving fluorinated carboxylate tecton via the modulation of heterocyclic N-donor co-ligands

Three new fluorous coordination polymers with a fluorinated carboxylate tecton and N-donor co-ligands, {[Zn₂(hfipbb)₂(phen)₂]·2H₂O}_n (1), [Zn₂(hfipbb)₂(bipy)(H₂O)]_n (2), and [Zn₅(hfipbb)₄ (Hhfipbb)₂ (bpp)]_n (3), [H₂hfipbb = 4,4′-(hexafluoroisopropylidene)bis(benzoic acid), phen = 1,10-phenthroline, bipy = 4,4′-bipyridine, and bpp = 1,3-bi(4-pyridyl)propane], have been prepared and characterized by elemental analysis, IR spectra, and X-ray diffraction. Compound 1 exhibits a 3D supramolecular network assembled from two independent 1D chain motifs [Zn(hfipbb)(phen)] through π?π stacking, and C-H?F and O-H?O interactions. Compound 2 features 2D undulating layer structure with 4⁴-sql network. Whereas, in compound 3, pentanuclear [Zn₅(η²-O)₂(μ²-η¹:η¹-CO₂)]²⁻ cores are bridged by hfipbb²⁻ and bpp ligands into a 3D 6-connected sxd framework with a point symbol of (3³·4⁶·5⁵·6). The diverse arrangements of the compounds show the modulation of the heterocyclic N-donor co-ligands can suitably mediate the coordination requirement of metal centers as well as the binding modes of fluorinated carboxylate tecton, which consequently generate diverse crystalline architectures. In addition, the properties of thermogravimetric analysis, X-ray powder diffraction, and photoluminescent behaviors of the compounds have also been discussed.     

4-羟基吡啶-2，6-二羧酸配体构筑的环状四核镉配合物的水热合成、晶体结构及性质研究

在水热条件下合成了一个金属镉配合物[Cd4(cam)4(phen)4]·4H2O(H2cam=4-羟基吡啶-2,6-二羧酸,phen=1,10-邻菲咯啉),并用元素分析、红外光谱、X-射线单晶衍射、热重分析和荧光分析对其进行了表征。晶体结构表明:该配合物属于单斜晶系,P21/c空间群,晶胞参数为:a=1.42161(10)nm,b=1.94642(13)nm,c=1.43966(10)nm,β=115.3850(10)°。每个CdⅡ离子七配位呈变形五角双锥几何构型,两对CdII离子与4个(cam)2-离子相连形成了环状四核结构。相邻的四核单元通过氢键的识别作用形成二维超分子网;氢键和π…π堆积作用进一步将其扩展为三维超分子结构。     

吲哚乙酸及邻菲啰啉的锌(Ⅱ)配合物的晶体结构及荧光性质

利用3-吲哚乙酸(IAA)、邻菲啰啉(o-phen)和氯化锌在水-乙醇体系合成了一种金属配合物[Zn(IAA)2(o-phen)](1),并对其进行了X-射线单晶衍射分析、热重分析、元素分析、红外光谱、紫外光谱、荧光光谱表征。结构分析表明,该配合物中,锌离子处于四配位的四面体构型中,分别与2个IAA阴离子的羧基氧原子及1个邻菲啰啉的2个氮原子配位。通过超分子作用力:氢键和面对面式的π…π堆积作用力的自组装作用使这些分子形成二维的超分子层结构,继而这些层层间通过边对面式的π…π堆积作用力进一步的组装成三维的超分子结构。热重分析显示,该配合物具有较高的热稳定性。配合物的液态及固体荧光性质研究表明,此配合物具有一定荧光性质。     

Synthesis,Crystal Structure and Luminescent Property of a Ternary Complex [Cd(sfdb)(3-pytpy)]<Subscript>2</Subscript>·2H<Subscript>2</Subscript>O (H<Subscript>2</Subscript>sfdb = 4,4′-Sulfonyldibenzoic Acid, 3-pytpy = 4′-(3-Pyridyl)-2,2′:6′,2″-Terpyridine)

Abstract  

A new ternary complex [Cd(sfdb)(3-pytpy)]₂·2H₂O (H₂sfdb = 4,4′-Sulfonyldibenzoic acid, 3-pytpy = 4′-(3-pyridyl)-2,2′:6′,2″-terpyridine) 1 has been hydrothermally synthesized and characterized by the elemental analysis, IR spectroscopy and single crystal X-ray diffraction. X-ray diffraction analysis reveals that 1 (C₃₄H₂₄CdN₄O₇S) crystallizes in triclinic space group P-1, features an interesting 1D channel-containing supramolecular structure constructed from grid-like dimers via π–π stacking interactions. Unit cell parameters for 1: a = 8.866(2) ?, b = 11.083(3) ?, c = 15.790(4) ?, α = 103.612(4)°, β = 95.044(3)°, γ = 101.083(4)° and Z = 2. The luminescent spectrum shows the emission peak of complex 1 is at 392 nm which is attributed to the intraligand transition.