Enhanced Activity of Enzyme Immobilized on Hydrophobic ZIF-8 Modified by Ni2+ Ions

The development of efficient enzyme immobilization to promote their recyclability and activity is highly desirable. Zeolitic imidazolate framework-8 (ZIF-8) has been proved to be an effective platform for enzyme immobilization due to its easy preparation and biocompatibility. However, the intrinsic hydrophobic characteristic hinders its further development in this filed. Herein, a facile synthesis approach was developed to immobilize pepsin (PEP) on the ZIF-8 carrier by using Ni²⁺ ions as anchor (ZIF-8@PEP-Ni). By contrast, the direct coating of PEP on the surface of ZIF-8 (ZIF-8@PEP) generated significant conformational changes. Electrochemical oxygen evolution reaction (OER) was employed to study the catalytic activity of immobilized PEP. The ZIF-8@PEP-Ni composite attains remarkable OER performance with an ultralow overpotential of only 127 mV at 10 mA cm⁻², which is much lower than the 690 and 919 mV overpotential values of ZIF-8@PEP and PEP, respectively.     

一个富路易斯碱位配合物的合成、结构及对痕量Ag+的荧光检测

通过溶剂热方法合成了一个由氢键拓展的携带路易斯碱位的三维超分子配位聚合物：{[Cd（HTZ-IP）（HPYTZ）（H₂O）₂]·5H₂O}_n（HTZ-H₂IP=5-（5-四氮唑基）间苯二甲酸;HPYTZ=3,5-（4-吡啶基）-1,2,4-三唑]。X射线单晶衍射结果表明,中心镉离子由含氮杂环羧酸配体和富氮辅助配体连接成"有悬挂手臂"的一维链,而链间则凭借配位水和2个配体的氢键作用拓展成三维超分子化合物。有趣的是配合物存在大量裸露的未配位的N原子,此N原子具有路易斯碱性质,能与路易斯酸性质的Ag⁺有效结合,从而引起配合物的荧光猝灭。该性质能在无色溶液中有效检测10^-4~10^-6 mol·L^-1范围内的痕量Ag⁺离子。     

Preparation of magnetic poly(methylmethacrylate–divinylbenzene–glycidylmethacrylate) microspheres by spraying suspension polymerization and their use for protein adsorption

Moderately uniform magnetic poly(methylmethacrylate–divinylbenzene–glycidylmethacrylate) microspheres (poly(MMA–DVB–GMA) microspheres) were prepared by spraying suspension copolymerization of methyl methacrylate, divinylbenzene and glycidyl methacrylate in the presence of Fe₃O₄ magnetic fluid. A protein adsorption assay indicated that these magnetic microspheres could significantly improve the capacity of protein adsorption.     

基于3-吡唑-5吡啶-1,2,4-三唑和均苯四甲酸构筑的两个同构配位聚合物的晶体结构和磁性

以3-吡唑-5吡啶-1,2,4-三唑(H2L)和均苯四甲酸(H_4btec)为配体合成了2个新的同构配位聚合物[M(btec)_(0.5)(H_2L)]_n(M=Co(Ⅱ)(1),Cu(Ⅱ)(2)),通过X射线单晶衍射、元素分析、红外光谱等进行了结构表征。晶体结构分析表明配合物1和2是同构的,都属于正交晶系,空间群为Pbca。2个配位聚合物都是二维结构,通过N…H…O氢键形成三维超分子框架结构。此外对上述配合物进行了磁性研究,结果表明配合物1内通过羧基桥连的金属钴离子之间是弱的铁磁相互作用;配合物2中存在典型的順磁行为。     

Stereoselective cis-dihydroxylation of azulene and related non-aromatic polyenes

Dioxygenase-catalysed dihydroxylation of azulene and related non-aromatic polyenes has been found to yield enantiopure chiral cis-diols of synthetic potential.     

Syntheses,Crystal Structure,and Magnetic Property of a New Mn(II) Complex with an Aromatic N-heterocyclic Tetracarboxylic Acid Ligand

Russian Journal of Coordination Chemistry - A new 2D Mn(II) complex named as [Mn3(HL)2(H2O)6]n (I) (H4L = 3-(2,4-dicarboxyphenyl)-2,6-dicarboxypyridine) was synthesized and characterized by IR,...     

Two Zinc(II)/Cadmium(II) Coordination Polymers Constructed by Semirigid Carboxylic Acid Ligand: Syntheses,Structures, and Photoluminescence Properties

Russian Journal of Coordination Chemistry - Two new coordination polymers {[Zn(HL)(HBpp)] · H2O}n (I) and [Cd(HL)(HBpe)]n (II) (H4L = 5-(2,3-dicarboxy phenoxy) isophthalic acid, Bpp =...     

基于柔性的高酞酸和双咪唑型配体的Ni(Ⅱ)/Cd(Ⅱ)/Zn(Ⅱ)配位聚合物的合成、结构和性质（英文）

基于柔性的高酞酸(H2hmph)和双咪唑型配体,通过溶剂热法合成了3种新的配位聚合物:{[Ni2(hmph)2(bib)2(H2O)2]·3H2O}n(1)、[Cd(hmph)(bib)]n(2)和{[Zn(hmph)(bip)]·H2O}n(3),其中bib=1,4-双(1-咪唑基)苯、bip=3,5-双(1-咪唑基)吡啶。配合物1是由Ni-羧酸链之间通过bib配体桥联而成的二维单层结构;配合物2为Cd-羧酸双股链之间通过bib配体拓展而成的二维双层结构,并含有由羧基连接的双核单元;配合物3是由羧酸连接而成的双核Zn单元通过bip配体拓展形成的双股链。3个配合物都具有较高的热稳定性。磁性分析表明在配合物1中存在铁磁性交换偶合作用。另外,配合物2和3的荧光性质与相应的配体相比都表现出明显的蓝移。     

Two New Cd(II) Coordination Polymers Based on Triazolyl Derivative and Different Carboxylate Ligands,Their Crystal Structures and Properties

Russian Journal of General Chemistry - Two new mixed-ligand coordination polymers of Cd(II), namely, [Cd(H2L)(ip)H2O]n (1) and [Cd(H2L)(Hbtc)]n (2) [H2L =...