Mo_8~ⅤW_2~ⅥO_(26)(C_5H_5N)_8·2H_2O: A Novel Mixed-valence Heterometal Polyoxometalate

A new mixed-valence heterometal cluster Mo8VW2VIO26(C5H5N)8·2H2O has been synthesized under solvothermal conditions and characterized by X-ray single-crystal diffraction, IR, UV-vis and XPS spectroscopy. The title compound crystallizes in the triclinic system, space group P1 with a = 11.708(3), b = 12.018(4), c = 13.316(4) , a = 112.184(4), β = 97.844(4), r = 110.043(3)o, V = 1551.9(8) 3 and Z = 1 at 293(2) K. The final full-matrix least-squares refinement converged to R = 0.0414 for 4460 observed unique reflections with I 2σ(I) and w R = 0.1290 for all data(5352) and S = 1.015. In addition, its thermal stability and fluorescent property have also been investigated.     

Synthesis,Crystal Structure and Characterization of a Ni(Ⅱ) Complex of Constructed 2,6-Bis(benzimidazol-2-yl) pyridine

A fluorescent Ni(II) complex 1, [Ni(OH-H2Bdc)(Bibimp)]n·nH2O, constructed with 5-hydroxyisophthalic acid(OH-H2Bdc) and 2,6-bis(2-benzimidazolyl)pyridine)(Bibimp) has been synthesized by hydrothermal methods and structurally characterized by elemental analysis, IR spectroscopy, TG/DTG, fluorescence spectrum and single-crystal X-ray diffraction. The title complex crystallizes in triclinic system, space group P1 with a = 10.187(2), b = 10.273(2), c = 13.401(3), α = 69.65(3), β = 69.66(3), γ = 70.61(3)o, V = 1196.8(4) 3, and Z = 2. The adjacent chains of complex 1 are stacked offset with respect to each other in an ABAB fashion by van der Waals interactions, and only a weak interlayer nonclassical C–H···O hydrogen bond has been observed. Complex 1 displays strong blue fluorescent emissions at 483 nm in the solid state upon photo-excitation at 365 nm at room temperature.     

Syntheses,Crystal Structures,and Biological Activities of Two 5-Pyrimidinyl-1,2,4-oxadiazoles

Two 5-pyrimidinyl-1,2,4-oxadiazoles were synthesized through two different routes and their structures were characterized by single-crystal X-ray diffraction, NMR and MS. Compound 3, 5-(2-chloro-4-methyl-6-phenylpyrimidin-5-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in orthorhombic, space group Pbca with a = 19.1575(11), b = 8.2115(5), c = 21.2035(12), V = 3335.6(3)3 and Z = 4. Compound 6, 5-(2,6-dichloropyrimidin-4-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in monoclinic space group Pn with a = 8.4275(13), b = 5.4088(8), c = 13.493(2), β = 99.768(3)o, V = 4658.6(6)3 and Z = 8. Preliminary bioassay indicated that the two title compounds had good herbicidal activities.     

A New Tetranuclear Cobalt Cluster with （1H-Benzimidazol-2-yl）-methanol Synthesis and Crystal Structure

A new tetranuclear cluster [Co4(bm)6Cl2]·(H2O)2·(CH3OH)(1, Hbm is(1H-benzimidazol-2-yl)-methanol) has been synthesized by solvothermal method and structurally determined by IR, elemental analysis, and single-crystal X-ray diffraction. Complex 1 belongs to monoclinic space group P21/n with a = 21.1713(5), b = 12.7948(3), c = 24.0195(9) , β = 95.309(3)°, V = 6478.6(3) 3, Z = 4, F(000) = 2568, Dc = 1.289 g·cm–3, Mr = 1257.63, μ = 9.096 mm–1, S = 1.000, the final R = 0.0861 and wR = 0.2552 for 4956 observed reflections with I 2σ(I). Two connected face-sharing cubes are observed in the framework of 1, each with one vertex missing. Complex 1 forms a 2-D network through N–H···O hydrogen bonds. The apparent holes can be observed.     

Synthesis and Characterization of Two Binuclear Macrocyclic Zinc(Ⅱ) Complexes by Anion Exchange

Two macrocyclic zinc(II) complexes {[ZnL(VO3)2]·0.33H2O}n(1) and [ZnL(H2O)2][Ni(CN)4](2)(L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) have been obtained from the reactions of [ZnL](ClO4)2 with NH4VO3 and K2[Ni(CN)4], respectively, and structurally characterized by elemental analysis, IR, XRPD, TG and X-ray diffraction. Single-crystal X-ray diffraction analyses indicated that the Zn(II) atom lies on an inversion center and is octahedrally coordinated by four nitrogen atoms of the tetradentate macrocyclic ligand in the equatorial plane and two oxygen atoms of [VO4] tetrahedra in the axial positions in 1, and two oxygen atoms of two water molecules in 2. Complex 1 shows a three-dimensional structure, which is constructed by the links of [VO3]nn- chains with [ZnL]2+, forming one-dimensional channels occupied by guest water molecules. The monomers of [ZnL(H2O)2]2+ and [Ni(CN)4]2- are connected through the intermolecular hydrogen bonds to form a two-dimensional sheet in complex 2.     

Synthesis and Crystal Structure of a New Pr(Ⅲ)–K(Ⅰ) Heterometallic Oxalate Coordination Polymer

A new 3D heterometallic coordination polymer, namely [K2Pr2(C2O4)4·H2O]n(1), has been successfully synthesized under hydrothermal conditions. X-ray single-crystal diffraction determination reveals that 1 crystallizes in monoclinic system, space group P21/n with a = 12.060(4), b = 8.493(3), c = 15.776(5)(A), β = 93.235(3)°, V = 1613.4(9) 3, Z = 4, Mr = 730.12, Dc = 3.006 Mg/m3, μ = 6.581 mm-1, F(000) = 1368, the final R = 0.0283 and w R = 0.0866 for 2939 observed reflections with I 2σ(I). Complex 1 features an unusual 3D heterometallic coordination framework, in which oxalates exhibit three different coordination behaviours. Moreover, powder X-ray diffraction and thermal properties for 1 have also been investigated.     

Studies on crystal transition of polyamide 11 nanocomposites by variable-temperature X-ray diffraction

Polyamide I1 （PAll） and its nanocomposites with different organoclay loadings were prepared by melt-compounding and subsequent pelletizing. The crystal phase transitions of PAl 1 and its clay nanocomposites were investigated by variable-temperature X-ray diffraction. It was found that the Brill transition of the nanocomposite was 20 K higher than that of the neat PAl 1 for both heating and cooling processes. The PAl 1 d-spacings of the nanocomposites were observed to be smaller than those of the neat PAl 1 for melt crystallization. The constraints imposed by the addition of layered clay, restricting the thermal expansion of the polymer chains, are probably responsible for such a reduction of the d-spacing.     

基于ITO微电极阵列的电致化学发光多元免疫反应传感芯片

制备了一种基于ITO微电极阵列的多元免疫反应芯片,并实现多元肿瘤标志物的快速、灵敏检测。采用丝网印刷方法制作"花瓣型"ITO微电极阵列,与辐射状的微流控芯片相结合,形成八个独立的检测单元,每个检测单元履行不同的职能,其中三个单元分别用于完成癌胚抗原(CEA)、甲胎蛋白(AFP)和前列腺特异性抗原(PSA)的"夹心型"特异性免疫反应。首先在电极表面修饰K-掺杂石墨烯-CdS∶Eu纳米晶复合物,然后在这些复合物上依次修饰不同捕获抗体和对应的抗原,当对应的CdTe纳米粒子标记的二抗被带到电极表面时,会发生能量转移而实现电致化学发光(ECL)信号的有效猝灭;另外三个单元用做对照试验来验证这种微芯片的选择性;剩下的两个单元分别用来验证K-掺杂石墨烯-CdS∶Eu纳米晶复合物的发光强度,及经活化后CdTe纳米粒子的猝灭效率。这种简单、集成的高通量检测芯片,可发展为复杂样品的自动化、集成化分析检测平台。     

纳米材料催化发光分析研究进展

本文综述了近年纳米材料催化发光分析在快速检测、分析物区分及高通量筛选催化剂等方面的研究进展,并对其今后的发展方向进行了展望。     

常见客体分子对笼型水合物晶格常数的影响

Natural gas hydrates are considered as ideal alternative energy resources for the future, and the relevant basic and applied research has become more attractive in recent years. The influence of guest molecules on the hydrate crystal lattice parameters is of great significances to the understanding of hydrate structural characteristics, hydrate formation/decomposition mechanisms, and phase stability behaviors. In this study, we test a series of artificial hydrate samples containing different guest molecules (e.g. methane, ethane, propane, iso-butane, carbon dioxide, tetrahydrofuran, methane + 2, 2-dimethylbutane, and methane + methyl cyclohexane) by a low-temperature powder X-ray diffraction (PXRD). Results show that PXRD effectively elucidates structural characteristics of the natural gas hydrate samples, including crystal lattice parameters and structure types. The relationships between guest molecule sizes and crystal lattice parameters reveal that different guest molecules have different controlling behaviors on the hydrate types and crystal lattice constants. First, a positive correlation between the lattice constants and the van der Waals diameters of homologous hydrocarbon gases was observed in the single-guest-component hydrates. Small hydrocarbon homologous gases, such as methane and ethane, tended to form sI hydrates, whereas relatively larger molecules, such as propane and iso-butane, generated sⅡ hydrates. The hydrate crystal lattice constants increased with increasing guest molecule size. The types of hydrates composed of oxygen-containing guest molecules (such as CO₂ and THF) were also controlled by the van der Waals diameters. However, no positive correlation between the lattice constants and the van der Waals diameters of guest molecules in hydrocarbon hydrates was observed for CO₂ hydrate and THF hydrate, probably due to the special interactions between the guest oxygen atoms and hydrate "cages". Furthermore, the influences of the macromolecules and auxiliary small molecules on the lengths of the different crystal axes of the sH hydrates showed inverse trends. Compared to the methane + 2, 2-dimethylbutane hydrate sample, the length of the a-axis direction of the methane + methyl cyclohexane hydrate sample was slightly smaller, whereas the length of the c-axis direction was slightly longer. The crystal a-axis length of the sH hydrate sample formed with nitrogen molecules was slightly longer, whereas the c-axis was shorter than that of the methane + 2, 2-dimethylbutane hydrate sample at the same temperature.