金属-有机配位聚合物在催化性能上的研究进展

多孔金属-有机配位聚合物(Metal-Organic Coordination Polymers-MOCPs)是一种新型功能材料,可通过其构件分子(金属离子和有机配体分子)的组合对孔穴大小、形状和表面特性进行调控,从而赋于它独特的结构和特性,在催化性能、分子识别、气体吸附、光学、磁性材料等方面具有诱人的发展前景.本文系统介绍了MOCPs在催化性能上的研究进展及其合成途径,并对MOCPs酶模拟体系在传感器方面的应用进行了展望.     

多孔金属-有机络合聚合物结构特征与其吸附行为关系

综述了近来出现的一类有前途的多孔材料--金属-有机络合聚合物(MOCPs)吸附功能的设计策略与合成途径.通过配体结构的选择或修饰可赋予MOCPs特定吸附性的孔环境;或采用适当的设计和合成策略使过渡金属离子和有机配体形成的骨架结构对特定吸附质分子具有特定的选择性.为新型的多孔吸附剂的设计与制备提供了一种新思路.     

金属-有机络合聚合物(MOCPs)的研究进展

从配体的角度对中心离子与多齿配体间形成的稳定多孔金属-有机络合聚合物(MOCPs)的发展现状进行了综述.指出该材料自成为研究热点以来,各研究小组在对不同的构件分子进行组合构建新的MOCPs方面富有成效的工作,极大地丰富了络合聚合物的结构数据,但这种材料最引人注目的特性--孔及表面性质的可调控性及其对其各种应用特性,如分子识别、择形催化、择形吸附等所能带来的影响方面的研究还很不够.     

具有手性分离功能的MOCPs的构建

就手性在药物分离中的重要性及手性分离剂的分离机制进行了概述.以此为基础,对一类在手性分离领域有巨大发展潜力的功能材料--金属有机络合聚合物(MOCPs)在分子设计和合成方面的研究现状进行了综述.MOCPs优异的理化性能、孔结构特性和手性分离功能可通过其构建分子的选择和修饰进行设计,其手性结构可通过手性配体与非手性配体进行构建.MOCPs有望在手性分离,特别是在手性药物分离领域形成新的研究和应用的热点.     

分子印迹聚合物在分离领域的应用

分子印迹技术是近年来集高分子合成、分子设计、分子识别、仿生生物工程等众多学科优势发展起来的一种应用广泛的新型技术.阐述了分子印迹方法的基本原理,介绍了分子印迹聚合物在分离领域的应用.综述了该技术的研究现状,并展望了其发展趋势.     

新型化学功能材料——瓜环与荧光化合物的主客体自组装研究进展

瓜环作为第四代超分子主体,两端由羰基氧原子环绕而成,内部为疏水性的空腔,具有刚性结构,微溶于水,不溶于有机溶剂。能与瓜环组成配合物的荧光类客体种类较多,通过荧光光谱的变化可以检测出主-客体相互作用,这一特性拓展了瓜环在生物化学领域的应用,包括医药载体、核酸检测、分子识别、pH探针等方面。未来研究中可以尝试以不同的发色母体取代不同的位点,这将为新型荧光试剂的设计与开发提供重要思路。     

一种新的酶模拟体系——催化性金属-有机络合聚合物

综述了近来出现的一类新的多孔材料--金属-有机络合聚合物(MOCP)催化功能的设计策略及合成途径.通过配体结构的选择或修饰可得到催化性的孔环境或采用适当的合成策略使过渡金属离子保留不饱和位点,结合MOCP孔道对分子的择形和筛分作用,赋予MOCP以酶样催化功能,从而得到一种新的酶模拟体系--催化性金属-有机络合聚合物(cMOCPs).cMOCPs在择形催化,尤其在不对称催化应用方面具有诱人前景,也给设计新型催化剂提供了一个新的思路.     

分子印迹聚合物

简单介绍了分子印迹聚合物(MIP)的制备及其分子识别机理,重点总结了MIP在分离领域的应用.     

分子印迹聚合物结合与识别能力的影响因素

分子印迹技术是近年来迅速发展起来的一种分子识别技术,被应用于色谱分离、固相萃取、药物分析、环境监测、仿生传感器、催化等领域.结合与识别能力是分子印迹聚合物的重要性能,详细分析了分子印迹聚合物结合与识别能力的影响因素.     

分子印迹聚合物的热力学与物理表征及模拟研究进展

分子印迹聚合物(MIPs)是一种对目标分子具有特异选择性和识别能力的高分子功能材料。文中从印迹聚合物预聚复合物的形成,聚合过程中印迹网络的构成以及聚合后的吸附性能及吸附位点等几方面综述了分子印迹聚合物的热力学、物理表征和模拟在分子印迹聚合物理论研究中的进展。     

On the balance of interaction modes in supramolecular complexes of a carboxylic acid host and alcohol guests. X-ray crystal structures of inclusion compounds with MeOH and EtOH

Remarkable differences have been observed between the host–guest interaction modes in two closely related crystalline inclusion compounds [1·MeOH (1:1) and 1·EtOH(1:1)] of the same carboxylic host (1). The minor modification of the guest structure crucially affected the hydrogen bonding recognition pattern between given complementary groups, which demonstrates the sensitive balance of intermolecular interaction modes that must be controlled for successful crystal engineering and design of supramolecular compounds.     

Chemical selectivity of self-assembled monolayers of calix[4]resorcinarene

Selective molecular interactions at an interface formed by self-assembly of a macrocyclic synthetic host, calix[4]resorcinarene with four thiol groups (R4SH), are investigated. The recognition of guest adsorbates from aqueous solutions is monitored using surface plasmon resonance (SPR) and the orientation of the guest-molecule is probed using polarization modulation infrared absorption spectroscopy (PM-IRRAS). The experiments reported here demonstrate that the chemical selectivity of self-assembled monolayers (SAMs) of host molecules such as calix[4]resorcinarenes extends to isomers of several different guest molecules. By using structural isomers of guest molecules such as bipyridine and nitrophenol that are multidentate hydrogen bond acceptors, it is shown that geometric match between guest and host molecules is an integral aspect of the recognition phenomena. Results from SPR and PM-IRRAS experiments reported here highlight the interplay between steric size and forces such as hydrogen bonding and hydrophobic interactions. Competitive and sequential adsorption of guest molecules such as -hydroxy-γ-butyrolactone and 4,4′-bipyridine shows that these guests compete for the same binding sites on the surface and that the interplay between steric size and molecular forces underlies the preferential selectivity of one guest molecule over another.     

Exploiting metal-organic coordination polymers as highly efficient immobilization matrixes of enzymes for sensitive electrochemical biosensing

We report on the exploitation of metal-organic coordination polymers (MOCPs) as new and efficient matrixes to immobilize enzymes for amperometric biosensing of glucose or phenols. A ligand, 2,5-dimercapto-1,3,4-thiadiazole (DMcT), two metallic salts, NaAuCl(4) and Na(2)PtCl(6), and two enzymes, glucose oxidase (GOx) and tyrosinase, are used to demonstrate the novel concept. Briefly, one of the metallic salts is added into an aqueous suspension containing DMcT and one of the enzymes to trigger the metal-organic coordination reaction, and the yielded MOCPs-enzyme biocomposite (MEBC) is then cast-coated on an Au electrode for biosensing. The aqueous-phase coordination polymerization reactions of the metallic ions with DMcT are studied by visual inspection as well as some spectroscopic, microscopic, and electrochemical methods. The thus-prepared glucose and phenolic biosensors perform better in analytical performance (such as sensitivity and limit of detection) than those prepared by the conventional chemical and/or electrochemical polymerization methods and most of the reported analogous biosensors, as a result of the improved enzyme load/activity and mass-transfer efficiency after using the MOCPs materials with high adsorption/encapsulation capability and unique porous structure. For instance, the detection limit for catechol is as low as 0.2 nM here, being order(s) lower than those of most of the reported analogues. The enzyme electrode was also used to determine catachol in real samples with satisfactory results. The emerging MOCPs materials and the suggested aqueous-phase preparation strategy may find wide applications in the fields of bioanalysis, biocatalysis, and environmental monitoring.     

A functional zeolite analogue assembled from metalloporphyrins

The assembly of molecular building blocks with metal ions generating microporous network solids has been the focus of intense activity. Because of their potential applications associated with channels and cavities, such materials have been examined for size- and shape-selective catalysis, separations, sensors, molecular recognition and nanoscale reactors. Within this context, assemblies of robust and chemically versatile porphyrin and metalloporphyrin building blocks remain rare. Supramolecular architectures of porphyrin solids based on weak van der Waals interactions, hydrogen bonding and metal-ligand coordination networks have been reported. Although there are frequent allusions to zeolite-like microporosity from crystallography and loss of initial guest solvent molecules, evidence of functional microporous behaviour is scarce. We have demonstrated repeatable sorption-desorption with high selectivity on the basis of size, shape and functional group of the sorbate by a microporous metalloporphyrin solid in analogy to zeolites.     

Cucurbit[8]uril as building block for facile fabrication of well-defined organic crystalline nano-objects with multiple morphologies and compositions

Cucurbit[n]urils (CB[n]) have great potential in material and medical applications due to their advantageous molecular recognition properties. Despite organic microcrystals being highly desirable in materials science and the medical industry, CB[n]-based micro- and nanocrystals have not been reported. A facile and efficient approach for producing CB[8]-based organic crystals with well-defined micro- and nanostructures is described, based on the unique host-guest chemistry of CB[8] macrocycle with small guest molecules. The described strategy allows fabrication of micro- and nanocrystals with multiple morphologies and compositions by simply adjusting the preparation conditions and the type of guest molecules. The mechanisms for the formation of the micro/nanocrystals are studied, and morphology-dependent optical and thermal properties typical of organic micro/nanocrystals are described. Additionally, attractive potentials of the prepared microcrystals are shown upon storing small molecules, and in optical applications. The molecular recognition abilities of CB[8] are highlighted in both its preparation process and potential application.     

Recent Advances on Host–Guest Material Systems toward Organic Room Temperature Phosphorescence

The design and characterization of purely organic room-temperature phosphorescent (RTP) materials for optoelectronic applications is currently the focus of research in the field of organic electronics. Particularly, with the merits of preparation controllability and modulation flexibility, host–guest material systems are encouraging candidates that can prepare high-performance RTP materials. By regulating the interaction between host and guest molecules, it can effectively control the quantum efficiency, luminescent lifetime, and color of host–guest RTP materials, and even produce RTP emission with stimuli-responsive features, holding tremendous potential in diverse applications such as encryption and anti-counterfeiting, organic light-emitting diodes, sensing, optical recording, etc. Here a roundup of rapid achievement in construction strategies, molecule systems, and diversity of applications of host–guest material systems is outlined. Intrinsic correlations between the molecular properties and a survey of recent significant advances in the development of host–guest RTP materials divided into three systems including rigid matrix, exciplex, and sensitization are presented. Providing an insightful understanding of host–guest RTP materials and offering a promising platform for high throughput screening of RTP systems with inherent advantages of simple material preparation, low-cost, versatile resource, and controllably modulated properties for a wide range of applications is intended.     

Tailor‐Made Receptors by Molecular Imprinting

Molecular recognition is becoming increasingly important in both research and industry (e. g. water purification). This review focuses on molecular imprinting with cyclodextrins—highly useful because of their hydrophilic exterior and hydrophobic cavity—including the very effective strategy adopted by the authors (see Figure): Several host species are assembled to form a tailor‐made guest complex with extremely exclusive selectivity.     

Fabrication of nanoporous networks with tunable triangular cavities with a molecular template

Herein we report a systematic construction of highly regular 2D triangular nanoporous networks by host-guest interaction. All molecular building blocks have the same four carboxylic acids groups, while the lengths of the blocks increase from 1.94 nm up to 2.90 nm. By using a suitably designed guest molecule, called coronene, we have fabricated steady porous network with tunable size of the edge length of the triangular pores of 3.2 nm, 3.7 nm and 4.1 nm at the liquid-solid interface. The results clearly demonstrate this approach may be also an efficient method to form the porous structures stable and controllable both in shape and in size.