晶态多孔材料合成方法的研究进展

晶态多孔材料是一类具有高孔隙率、多样结构、可控功能的功能材料,在客体分子吸附及分离、催化、储能等众多领域具有广阔的应用前景.其中,以沸石分子筛(zeolites)、金属有机框架材料(metal-organic frameworks, MOFs)和共价有机框架材料(covalent-organic frameworks, COFs)最具代表性.随着对晶态多孔材料研究的不断深入,众多新型的合成手段被开发用于材料的基础研究.同时,晶态多孔材料合成方法学的发展与其工业应用密切相关.本综述主要概述了晶态多孔材料的各种合成手段的优缺点和它们的潜在应用.     

多孔配位聚合物晶态转换研究进展（摘要）

近年来,多孔配位聚合物内客体分子去除或迁入导致的晶态转换及相关效应研究方兴未艾.晶态转换尤其是单晶到单晶结构转换作为研究主客体化学的新方法,可以揭示多孔配合物框架与客体分子之间的内在联系.本文从客体去除或迁入导致的晶态转换出发,重点介绍了本课题组多孔配位聚合物方面的工作以及近四年来国际上多孔配位聚合物晶态转换研究进展.其中,以单晶到单晶方式进行的多孔配位聚合物配体取代反应以及后合成调控,区别于传统的客体去除或交换引起的晶态转换,在本文中得到重点阐述.此外,本文简要概括了国内晶态转换研究现状.作为一个热点领域,研究晶态转换不仅有助于应对多孔配位聚合物体系实现吸附、磁性、光电性质多功能原位跟踪研究的挑战,也为未来设计客体导向的多孔智能材料提供研究方法与基础.随着X射线单晶衍射、X射线粉末衍射、同步辐射光源、中子衍射以及非弹性中子散射在内的系列结构表征技术的不断进步,必将极大促进晶态转换的研究.     

基于间苯三酚及其衍生物构筑新型有机多孔材料

有机多孔材料凭借其高比表面积、孔道可调性、易功能化修饰和结构多样性等特征,在催化、能源、吸附与分离等多个领域中展现了巨大应用潜力.对多官能度有机化合物单体以及高效聚合反应的巧妙应用,为新型有机多孔材料的创制提供了强有力的工具,成为该领域的研究热点.以C₃对称型的间苯三酚及其衍生物为例,综述了其在一系列新型有机多孔材料高效构筑中的最新研究进展.     

胺功能化配体多孔配位聚合物材料的碳捕捉和封存研究进展

近十年,多孔配位聚合物(porous coordination polymers, PCPs)因其晶体结构中可调节的孔道尺寸、形状以及化学功能化,在小分子的选择性吸附及分离领域受到了极大的关注。基于环境问题的严峻性,胺功能化PCPs材料对煤电厂燃烧废气中CO2优异的选择性吸附性能,使其在该领域拥有较好的应用潜力。本文综述了含末端氨基配体的PCPs材料应用于二氧化碳捕捉及存储的代表性工作,并对所存在的问题及发展方向进行了分析总结。     

一种新型酰胺功能化的共价有机框架用于选择性染料吸附

共价有机框架(covalent organic framework, COF)是一种由轻质元素(C、H、O和N)以共价键的形式连接组成的结晶多孔聚合物,由于其具有规则的孔道、可修饰的骨架以及良好的稳定性而被广泛应用于不同的领域.尤其是将含氮的功能基团连接到COF的骨架中,可以为其吸附特定的染料提供丰富的活性位点.基于此,本工作成功制备了一种酰胺功能化的二维共价有机框架材料(JUC-578),通过一系列的表征证明了该材料具有高的结晶度、均一规整的形貌以及开放的一维介孔孔道.更重要的是,发现JUC-578可以选择性地吸附阳离子染料,并且可以多次循环利用.这主要归因于骨架中的氮作为电子给体与缺电子的染料之间的静电作用以及其他弱相互作用(氢键、偶联作用等).与此同时,JUC-578高的结晶度和有序的孔道也是实现可逆吸附染料非常重要的因素.     

共价有机多孔聚合物合成新策略

共价有机多孔聚合物(COPs)是由有机结构单元通过共价键连接而形成的一类具有微孔或者介孔结构的新型高分子多孔材料, 在能源、物质吸附与分离、气体存储、光电器件、多相催化以及化学/生物传感等方面展现出巨大的应用潜能. 尽管其合成方法众多, 合成单体多样, 产物结构稳定, 但是传统方法合成的有机多孔材料大多是无定型的, 结构难以控制, 且通常不溶不熔, 很难再加工. 为了解决这些问题, 近年来很多新的合成方法和合成策略被开发出来, 为共价有机多孔聚合物的进一步发展指明了方向. 本文将对这些最新的研究进展做一简要的介绍.     

多孔骨架固定分子催化剂催化CO2加氢制备甲酸研究进展

近年来, 大气中CO₂含量急剧增加, 导致了严重的温室效应. 将CO₂作为C1资源转化为燃料或精细化学品引起了越来越多的关注. 开发高效、 稳定、 可回收利用的催化剂成为CO₂资源化利用的关键. 在众多的CO₂加氢催化剂中, 功能性多孔骨架材料固定型分子催化剂展示出优异的性能, 成为研究的热点之一. 功能性骨架材料, 如多孔有机聚合物(POPs)、 共价有机骨架(COFs)和金属有机骨架(MOFs), 具有比表面积大、 热稳定性高和可调性等特点, 在设计合成催化剂方面发挥着重要作用. 本文介绍了POPs/COFs/MOFs多孔骨架材料固定分子催化剂的开发及在催化CO₂合成甲酸领域的最新进展.     

功能性共轭多孔聚合物材料

有机多孔聚合物(organic porous polymers,OPPs)材料是一类由强共价键将不同几何构型的有机分子砌块链接而成的多维度的多孔网络骨架材料,近年来成为多孔材料发展的一个新方向.按其结构的有序程度划分,OPPs包括无定型(如CMPs,HCPs,PIMs,PAFs等)和晶态(如COFs,CTFs)多孔聚合物两大类.因具有质轻、较大的比表面积、优异的多孔特性、稳定性好、结构与功能可预先设计和精确调控等优点,OPPs在气体存储/分离,非均相催化,光电转换,化学/生物传感,能量存储与转换等诸多领域有着广泛的应用前景.基于"自下而上"的构筑策略,以一种或多种具有特定功能的有机共轭分子为构筑单元,通过其分子间的自聚或共聚来实现二维、三维共轭高分子网络的可控构筑,发展了一系列具有优异光电、催化性能的功能性有机骨架材料.本文总结了近年来作者所在课题组报道的以功能性共轭有机分子为反应单元,自下而上构筑共轭多孔聚合物材料的战略和方法,主要探索了其结构特征以及在光电转换和非均相催化领域等的初步应用.     

多孔有机框架材料在真菌毒素分离富集与检测中的研究进展北大核心CSCD

真菌毒素是真菌产生的一类有毒的次级代谢产物,对人体具有致癌、致畸、致突变等严重危害,已引起世界范围的广泛关注。因此,建立准确、快速、灵敏的真菌毒素检测方法具有非常重要的意义。色谱法是常用的检测真菌毒素的方法,但由于真菌毒素种类繁多,分布范围广泛,样品基质复杂,且各类真菌毒素在实际样品中含量极低,难以对其进行直接分析。因此,发展适宜的样品前处理方法,并用于真菌毒素的高效分离富集是必不可少的步骤。近年来,以金属有机框架(MOF)、共价有机框架(COF)为代表的多孔有机框架材料因具有大的比表面积、高的孔隙率、可调的孔径、多样的框架结构、活性位点分布均匀、结构可修饰等优点被广泛应用于真菌毒素的样品前处理领域。同时,这些优点赋予MOF/COF材料以优异的荧光性质、电化学性质,使其在真菌毒素的分析传感等领域也得到了广泛关注。本文针对近年来MOF/COF材料在真菌毒素分离富集中常用的样品前处理方法(固相萃取、分散固相萃取、磁固相萃取、免疫磁珠分离)中的应用进行了综述。同时,针对MOF/COF材料在真菌毒素荧光传感、电化学传感中的研究进行了总结。最后,对存在的问题及未来的发展趋势进行了讨论与展望,为进一步探索MOF/COF材料在真菌毒素中的应用提供参考。     

金属有机框架材料的研究进展

金属有机框架(metal-organic frameworks,MOFs)材料是一类由有机配体与金属中心经过自组装形成的具有可调节孔径的材料。与传统无机多孔材料相比,MOFs材料具有更大的比表面积,更高的孔隙率,结构及功能更加多样,因而已经被广泛应用于气体吸附与分离、传感器、药物缓释、催化反应等领域中。新兴材料的出现极大地促进了各个学科间的相互发展,本文综述了近年来MOFs材料的研究发展,包括MOFs材料自身的特点、国内外发展现状、应用领域以及复合MOFs材料的研究热点,并对今后的发展进行了展望。     

Hydrogen‐Bonded Organic Frameworks (HOFs): A New Class of Porous Crystalline Proton‐Conducting Materials

Two porous hydrogen‐bonded organic frameworks (HOFs) based on arene sulfonates and guanidinium ions are reported. As a result of the presence of ionic backbones appended with protonic source, the compounds exhibit ultra‐high proton conduction values (σ) 0.75× 10^?2 S cm^?1 and 1.8×10^?2 S cm^?1 under humidified conditions. Also, they have very low activation energy values and the highest proton conductivity at ambient conditions (low humidity and at moderate temperature) among porous crystalline materials, such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). These values are not only comparable to the conventionally used proton exchange membranes, such as Nafion used in fuel cell technologies, but is also the highest value reported in organic‐based porous architectures. Notably, this report inaugurates the usage of crystalline hydrogen‐bonded porous organic frameworks as solid‐state proton conducting materials.     

3D Microporous Base‐Functionalized Covalent Organic Frameworks for Size‐Selective Catalysis

The design and synthesis of 3D covalent organic frameworks (COFs) have been considered a challenge, and the demonstrated applications of 3D COFs have so far been limited to gas adsorption. Herein we describe the design and synthesis of two new 3D microporous base‐functionalized COFs, termed BF‐COF‐1 and BF‐COF‐2, by the use of a tetrahedral alkyl amine, 1,3,5,7‐tetraaminoadamantane (TAA), combined with 1,3,5‐triformylbenzene (TFB) or triformylphloroglucinol (TFP). As catalysts, both BF‐COFs showed remarkable conversion (96 % for BF‐COF‐1 and 98 % for BF‐COF‐2), high size selectivity, and good recyclability in base‐catalyzed Knoevenagel condensation reactions. This study suggests that porous functionalized 3D COFs could be a promising new class of shape‐selective catalysts.     

The Prospect of Dimensionality in Porous Semiconductors

With the advent of silicon-based semiconductors, a plethora of previously unknown technologies became possible. The development of lightweight low-dimensional organic semiconductors followed soon after. However, the efficient charge/electron transfers enabled by the non-porous 3D structure of silicon is rather challenging to be realized by their (metal-)organic counterparts. Nevertheless, the demand for lighter, more efficient semiconductors is steadily increasing resulting in a growing interest in (metal-)organic semiconductors. These novel materials are faced with a variety of challenges originating from their chemical design, their packing and crystallinity. Although the effect of molecular design is quite well understood, the influence of dimensionality and the associated change in properties (porosity, packing, conjugation) is still an uncharted area in (metal-)organic semiconductors, yet highly important for their practical utilization. In this Minireview, an overview on the design and synthesis of porous semiconductors, with a particular emphasis on organic semiconductors, is presented and the influence of dimensionality is discussed.     

Pillar-Layered Metal-Organic Frameworks for Sensing Specific Amino Acid and Photocatalyzing Rhodamine B Degradation

Metal-organic frameworks (MOFs) have presented potential for detection of specific species and catalytic application due to their diverse framework structures and functionalities. In this work, two novel pillar-layered MOFs [Cd₆(DPA)₂(NTB)₄(H₂O)₄]_n·n(DPA·5DMA·H₂O) (1) and [Cu₂(DPA)(OBA)₂]_n·n(2.5DMF·H₂O) (2) [DPA = 2,5-di(pyridin-4-yl)aniline, H₃NTB = 4,4′,4′′-nitrilotribenzoic acid, H₂OBA = 4,4′-oxydibenzoic acid, DMA = N,N-dimethylacetamide, DMF = N,N-dimethylformamide] were successfully synthesized and structurally characterized. Both 1 and 2 have three-dimensional framework structures. The fluorescent property of 1 makes it possible for sensing specific amino acid such as L-glutamic acid (Glu) and L-aspartic acid (Asp). While MOF 2 was found to be suitable for photocatalytic degradation of Rhodamine B (RhB) in the presence of H₂O₂. The results imply that MOFs are versatile and metal centers are important in determining their properties.     

Topology-Templated Synthesis of Crystalline Porous Covalent Organic Frameworks

A strategy is presented for the synthesis of crystalline porous covalent organic frameworks via topology-templated polymerization. The template is based on imine-linked frameworks and their (001) facets seed the C=C bond formation reaction to constitute 2D sp² carbon-conjugated frameworks. This strategy is applicable to templates with different topologies, enables designed synthesis of frameworks that cannot be prepared via direct polymerization, and creates a series of sp² carbon frameworks with tetragonal, hexagonal, and kagome topologies. The sp² carbon frameworks are highly luminescent even in the solid state and exhibit topology-dependent π transmission and exciton migration; these key fundamental π functions are unique to sp² carbon-conjugated frameworks and cannot be accessible by imine-linked frameworks, amorphous analogues, and 1D conjugated polymers. These results demonstrate an unprecedented strategy for structural and functional designs of covalent organic frameworks.     

氨基酸衍生物手性分离分子印迹聚合物

本文从识别机理,制备方法及其应用等方面简要介绍了近年来用于氨基酸衍生物手性分离的分子印迹聚合物的一些研究进展.     

Direct On‐Surface Patterning of a Crystalline Laminar Covalent Organic Framework Synthesized at Room Temperature

We report herein an efficient, fast, and simple synthesis of an imine‐based covalent organic framework (COF) at room temperature (hereafter, RT‐COF‐1 ). RT‐COF‐1 shows a layered hexagonal structure exhibiting channels, is robust, and is porous to N₂ and CO₂. The room‐temperature synthesis has enabled us to fabricate and position low‐cost micro‐ and submicropatterns of RT‐COF‐1 on several surfaces, including solid SiO₂ substrates and flexible acetate paper, by using lithographically controlled wetting and conventional ink‐jet printing.