Synthesis, structure and fluorescence of a novel diarylethene

The photochromic diarylethene, 1,2-bis(2-methyl-5-(2-(1,3-dithiolpentane))-thien-3-yl)perfluorocyclopentene (BMDTP), has been synthesized in high yield and its structure was determined by X-ray crystallographic analysis. The compound undergoes a photochromic reaction both in solution and in the single crystalline phase. In addition, its fluorescence property in solution is discussed.     

[M(en)3] (ndt)•H2O的水热合成、晶体结构和光学性能 ( M=NiⅡ, CoⅡ, MnⅡ and ndt=1,5-naphthalenedithiolate )

水热条件下，合成了三个新的配合物[Ni(en)₃] (ndt) ·H₂O 1, [Co(en)₃] (ndt) ·H₂O 2 和[Mn(en)₃] (ndt) ·H₂O 3。晶体结构通过X-射线单晶衍射进行了表征。三个配合物均属于单斜晶系，Cc空间群。[M(en)₃]²⁺阳离子、ndt阴离子和结晶水分子通过氢键自组装出相同结构的三维网。通过紫外-可见-近红外漫反射光谱对这三个配合物的光吸收性能和能带进行了测定。     

2020 Roadmap on two-dimensional nanomaterials for environmental catalysis

This roadmap demonstrates a series of two-dimensional nanomaterials, such as graphene, black phosphorus, oxides, layered double hydroxides, chalcogenides, bismuth-based layered compounds, MXenes, metal organic frameworks, covalent organic frameworks, and others, for environmental catalysis.     

Influence of the Size of Aromatic Chelate Ligands on the Structures of Cadmium(II) Tetracarboxylates Polymers: From 2D Layered Network to 3D Metal‐Organic Framework

To determine the influence of the size of the aromatic chelate ligands on the frameworks of metal tretracarboxylate polymers, two new coordination polymers [Cd(btc)_0.5 (2,2′‐bpy)] ( 1 ) and [Cd(btc)_0.5(phen)]·H₂O ( 2 ) (H₄btc = biphenyl‐3,3′,4,4′‐tetracarboxylic acid, 2,2′‐bpy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline) have been synthesized under similar hydrothermal conditions. In complex 1 , the dimeric Cd₂ units are linked by bridging btc^4? ligand to form a 2D layered network, whereas complex 2 possesses a 3D metal‐organic framework consisting of the dimeric Cd₂ units. The differences of two metal‐organic frameworks demonstrate that the size of the rigid aromatic chelate ligands have an important effect on the structures of their complexes. Additionally, the two complexes show strong fluorescence in the solid state at room temperature.     

Automated hollow fiber-protected dynamic liquid-phase microextraction of pesticides for gas chromatography-mass spectrometric analysis

Dynamic liquid-phase microextraction (LPME) controlled by a programmable syringe pump was evaluated for extracting pesticides in water prior to GC-MS analysis. A conventional microsyringe with a 1.3-cm length of hollow fiber attached to its needle was connected to a syringe pump to perform the extraction. The microsyringe was used as both the microextraction device as well as the sample introduction device for GC-MS analysis. The attached hollow fiber served as the "holder" and protector" of 3 microl of organic solvent. The solvent was repeatedly withdrawn into and discharged from the hollow fiber by the syringe pump. Pesticides were extracted from 4-ml water samples into the organic solvent impregnated in the hollow fiber. The effects of organic solvents, plunger movement pattern, agitation and extraction time were investigated. Good repeatabilities of extraction performance were obtained, with the RSD values ranging from 3.0% (alachlor) to 9.8% (4-chlorophenol) for the 14 pesticides; most RSD values were under 5.0%. The method provided a 490-fold preconcentration of the target pesticides. The limits of detection were in the range of 0.01-5.1 microg/l (S/N = 3) in the GC-MS selected ion monitoring mode. In addition, sample clean-up was achieved during LPME because of the selectivity of the hollow fiber, which prevented undesirable large molecules from being extracted. A slurry sample (mixture of 40 mg soil/ml of water) containing seven pesticides was extracted using this method which also gave good linearity and precision (most RSDs <7.0%, n = 3).     

Direct Synthesis, Crystal Structure and Thermal Kinetics of Supramolecular Complex [Co（H2O）6]·（Hnip）2·（H2nip）2·（DMA）2·（H2O）8 （nip=5-nitroisophthalate, DMA=CH3NHCH3）

The crystal of [Co（H2O）6]·（Hnip）2·（H2nip）2·（OMA）2·（H2O）8 has been cultured using direct method and characterized by X-ray single crystal diffractometry, elemental analysis and FTIR spectroscopy. It crystallizes in triclinic system, P-1 space group with the cell parameters of a=0.7012（1） nm, b=1.1378（2） nm, c=1.6612（3） nm, α= 84.92（3）°, β=85.19（3）°, γ=85.91（3）°, V= 1.3128（5） nm^3, Z=1, Dc= 1.573 g·cm^-3. Final R indices [1〉2σ（I）] are： R1 =0.0279, wR2=0.0765 while R indices for all data are： R1 =0.0327, wR2=0.0806. The Co coordination octahadra are each surrounded by two Hnip, two H2nip, two DMA and eight water molecules that are linked by hydrogen bonds and π-π stacking interactions. Thermal analyses of DSC and TG-DTG have been performed on the complex to predict its thermal decomposition mechanism and determine the most probable kinetic model function using Kissinger, Ozawa, integral and differential methods.     

Anion and Additive Effects on the Structure of Mercury(II) Halides Complexes with Tripodal Ligand

The metal complexes [Hg₂(tbim)₂Br₄]·2DMF ( 1 ) and [Hg₂(tbim)I₄]·1.5DMF ( 2 ) were prepared by reactions of 1,3,5‐tris(benzimidazol‐1‐ylmethyl)‐2,4,6‐trimethylbenzene (tbim) with HgBr₂, HgI₂, respectively, and [Hg₂(tbim)I₄]·0.5(FeCp₂)·H₂O ( 3 ) was obtained by the same method with addition of ferrocene (FeCp₂) as additive. Their structures were determined by X‐ray crystallographic analyses. Complex 1 has a macrocyclic binuclear structure with one benzimidazole arm of the ligand free of coordination and the binuclear units are further connected by C‐H···N hydrogen bonds to give an infinite zigzag chain. Complexes 2 and 3 have a 2D network structure in which tbim serves as a tridentate ligand. The results showed that the halides of bromide and iodide have remarkable impact on the structure of the complexes. The FeCp₂ molecules are trapped in the voids of framework 3 .     

氯化聚乙烯弹性体的固相法合成

讨论了以固相法合成氯化聚乙烯（ＣＰＥ）弹性体的过程．实验结果表明，以固相氯化反应所得的ＣＰＥ，其大分子链上Ｃｌ取代基的分布比水相悬浮法更均匀．氯化过程的温度直接影响氯化速度及分子结构，如残留结晶、氯分布等．而聚乙烯颗粒表面与内部的氯化程度取决于氯化速度．大分子链上Ｃｌ取代基对邻近基团的氯化起阻碍作用     

SNAP-tag蛋白标签技术与荧光分析法在蛋白原位分析中的联合应用

为将生物体内微观的蛋白行为可视化并以宏观信号呈现出来对蛋白进行实时、动态分析，借助SNAP-tag蛋白标签技术与有机小分子荧光染料，构建了一系列用于活细胞内实时监测目标蛋白的免洗荧光探针。标签蛋白SNAP-tag能够特异性识别探针中的苄基鸟嘌呤，从而使目标蛋白共价连接上荧光团（萘酰亚胺），携带上荧光信使。此外，由于萘酰亚胺从水环境中被牵引至SNAP-tag蛋白的疏水空腔，其荧光信号呈现出2~13倍的增强。通过SNAP-tag标签蛋白与目标蛋白的融合，该荧光探针实现了对活细胞内线粒体蛋白CoX8A及核内蛋白H2B特异性识别，在免洗条件下完成了对目标蛋白的实时追踪及原位分析。