共价有机骨架聚合物(COFs)的应用研究进展

共价有机骨架聚合物(COFs)是一类结晶微孔聚合物,具有优异的孔性质、高的热及化学稳定性和大的比表面积,在气体储存、催化、光电材料等诸多领域中有重要的应用前景,已成为国内外的研究热点。本文主要综述了共价有机骨架聚合物对氢气、甲烷、二氧化碳等气体的吸附与储存,并介绍了共价有机骨架聚合物近几年在非均相催化、光电材料、重金属离子吸附、光催化制氢等方面的应用所取得的重要进展。文章最后总结了当前共价有机骨架聚合物遇到的一些问题,并对该领域未来发展趋势进行了展望。     

卟啉共价有机框架化合物的研究进展

共价有机框架化合物(COFs)是一类新兴的具有多孔结构的晶态有机聚合物,在储存与分离、催化、能量转化等领域具有广泛应用。本文介绍了一类基于卟啉单元的COFs,从框架构筑及应用开发两方面综述了这类材料的研究进展。     

Metal–Covalent Organic Frameworks (MCOFs): A Bridge Between Metal–Organic Frameworks and Covalent Organic Frameworks

Many sophisticated chemical and physical properties of porous materials strongly rely on the presence of the metal ions within the structures. Whereas homogeneous distribution of metals is conveniently realized in metal–organic frameworks (MOFs), the limited stability potentially restricts their practical implementation. From that perspective, the development of metal–covalent organic frameworks (MCOFs) may address these shortcomings by incorporating active metal species atop highly stable COF backbones. This Minireview highlights examples of MCOFs that tackle important issues from their design, synthesis, characterization to cutting‐edge applications.     

Metal‐Ion Metathesis in Metal–Organic Frameworks: A Synthetic Route to New Metal–Organic Frameworks

A porous metal–organic framework, Mn(H₃O)[(Mn₄Cl)₃(hmtt)₈] (POST‐65), was prepared by the reaction of 5,5′,10,10′,15,15′‐hexamethyltruxene‐2,7,12‐tricarboxylic acid (H₃hmtt) with MnCl₂ under solvothermal conditions. POST‐65(Mn) was subjected to post‐synthetic modification with Fe, Co, Ni, and Cu according to an ion‐exchange method that resulted in the formation of three isomorphous frameworks, POST‐65(Co/Ni/Cu), as well as a new framework, POST‐65(Fe). The ion‐exchanged samples could not be prepared by regular solvothermal reactions. The complete exchange of the metal ions and retention of the framework structure were verified by inductively coupled plasma–atomic emission spectrometry (ICP‐AES), powder X‐ray diffraction (PXRD), and Brunauer–Emmett–Teller (BET) surface‐area analysis. Single‐crystal X‐ray diffractions studies revealed a single‐crystal‐to‐single‐crystal (SCSC)‐transformation nature of the ion‐exchange process. Hydrogen‐sorption and magnetization measurements showed metal‐specific properties of POST‐65.     

离子交换膜的渗透汽化

本文介绍了离子交换膜的渗透汽化研究工作。从离子交换膜的吸附溶解性、离子特性等几个方面论述了渗透汽化过程的分高性能及可能的传递机理。     

Solvent‐Dependent Cation Exchange in Metal–Organic Frameworks

We investigated which factors govern the critical steps of cation exchange in metal–organic frameworks by studying the effect of various solvents on the insertion of Ni²⁺ into MOF‐5 and Co²⁺ into MFU‐4l. After plotting the extent of cation insertion versus different solvent parameters, trends emerge that offer insight into the exchange processes for both systems. This approach establishes a method for understanding critical aspects of cation exchange in different MOFs and other materials.     

共价有机骨架材料在分离科学中的研究进展

共价有机骨架(COFs)材料是一类由有机单体通过共价键连接而成的新型多功能结晶有机聚合物,具有比表面积大、热和化学稳定性好、结构和功能可控等优点,在气体存储、药物传递、传感和催化等方面有着广泛的应用。多样的结构和丰富的官能团也使COFs在分离科学中具有巨大的应用潜力。COFs及其复合材料作为吸附剂已被用于固相萃取、磁固相萃取、固相微萃取,以及气相色谱、高效液相色谱和毛细管电色谱的新型固定相。该文综述了近3年来COFs在分离科学中的最新进展,着重介绍了COFs在水介质、食品基质、生物样本等复杂基质中样品前处理和有机分子(包括手性和异构化合物)分离等方面的研究进展,为进一步研究COFs的应用提供参考。     

有机多孔材料:合成策略与性质研究

多孔材料已经广泛应用于离子交换、吸附与分离、主客体化学等诸多领域. 多孔材料的研究同时具有基础和应用研究价值. 根据多孔材料的元素组成及键连方式, 多孔材料包括无机、无机-有机杂化和有机这三种形式的孔材料. 相对于无机孔材料及无机-有机孔材料研究, 有机多孔材料的研究时间较短. 构筑有机多孔材料的基块其结构丰富多样, 轻元素组成的有机基元通过共价键连接形成, 因此有机多孔材料具有骨架组成丰富、修饰性强、稳定性好、比表面积高、孔道结构可调等优点. 总结有机多孔材料的研究, 结合我们自己研究工作, 在这篇综述中我们将着重介绍它们的合成策略、气体储存、催化性能等.     

金属有机骨架材料在气体分离膜中的应用

金属有机骨架(Metal organic frameworks,MOF)是一种新型材料,有着比表面积高、孔径可调等优点,以此为基础制备MOF膜克服了 MOF材料界面相容性和热稳定性差的缺点,在气体分离领域具有良好的应用前景.本文介绍了 MOF膜的功能层应用、物理共混、界面聚合以及接枝改性;简述了每种方法对不同气体分离性...     

Rational Construction of Polymeric Cadmium(II) Benzimidazole for Transition Metal Ion Exchange

A 1D double‐helical coordination polymer {[Cd(pbbm)₂]₂(ClO₄)₄(H₂O)₂}_n ( 1 ) was successfully constructed by the reaction of Cd(ClO₄)₂ · 6H₂O with 1,1′‐(1,5‐pentanediyl)bis‐1H‐benzimidazole (pbbm). Interestingly, polymer 1 exhibits highly selective capacity for the ionic exchange of Zn²⁺ and Cu²⁺ over Co²⁺ and Ni²⁺ ions in the crystalline solid state when the crystals of 1 are immersed in the aqueous solutions of the perchlorate salts of Cu²⁺, Zn²⁺, Co²⁺, and Ni²⁺ ions, respectively, which indicates that central Cd^II ion exchange might be considered as being dominated by the coordination ability of metal ions to free functional groups, ionic radii of exchanged metal ions, and the solution concentration of adsorbed metal salts. The parent material‐ and ion‐exchange‐induced products are identified by FT‐IR spectroscopy, PXRD patterns as well as SEM and EDS measurements. In addition, the thermal stability of 1 was also investigated.     

Hydrogen-Bonded Organic Frameworks: Structural Design and Emerging Applications

Constructing well-organized organic frameworks with tailor-made functionalities potentially boost multi-domain applications. Hydrogen bonding (H-bonding) is a category of general and weak intermolecular interactions when compared with covalent bonding or metal-ligand coordination. Porous frameworks mainly assembled by H-bonding (named hydrogen-bonded organic frameworks, HOFs) are intrinsically capable of decomposing and regenerating, a distinctive advantage to improve their processability while expanding the applicability. This paper summarizes the basic building concepts of HOFs, including feasible hydrogen bonded motifs, effective molecular structures, and their emerging applications.     

Three-Dimensional Chemically Stable Covalent Organic Frameworks through Hydrophobic Engineering

The development of three-dimensional (3D) covalent organic frameworks (COFs) with high chemical stability is of critical importance for their practical use. In this work, it is demonstrated that the stability of 3D COFs can be improved by periodic decoration of isopropyl groups on their backbones. Owing to the strong hydrophobicity of the alkyl groups, the resultant COFs show high crystallinity, permanent pores, and exceptional stability in harsh environments, such as strong acids (3 m HCl or 3 m H₂SO₄ for one week), a strong base (20 m NaOH for one week), and boiling water (100 °C for one month). Furthermore, these highly stable and hydrophobic COFs display excellent oil/water separation performance with >99 % separation efficiency over a wide pH range. This work demonstrates the use of alkyl decoration in 3D COFs to tune their chemical stability and expand their potential applications.     

Single‐Crystal to Single‐Crystal Linker Substitution,Linker Place Exchange,and Transmetalation Reactions in Interpenetrated Pillared–Bilayer Zinc(II) Metal–Organic Frameworks

A twofold interpenetrated pillared–bilayer framework, {[Zn₃( L )₂( L₂ )(DMF)] ? (18DMF)(6H₂O)}_n ( 1 ), has been synthesized from the ligands tris(4′‐carboxybiphenyl)amine ( H₃L ) and 1,2‐bis(4‐pyridyl)ethylene ( L₂ ). The structure contains [Zn₃(COO)₆] secondary building units (SBUs), in which three Zn^II ions are almost linear with carboxylate bridging. This framework undergoes reversible pillar linker substitution reactions at the terminal Zn^II centers with three different dipyridyl linkers of different lengths to afford three daughter frameworks, 2 – 4 . Frameworks 2 – 4 are interconvertible through reversible linker substitution reactions. Also, competitive linker‐exchange experiments show preferential incorporation of linker L₃ in the parent framework 1 . The larger linker L₅ does not undergo such substitution reactions and framework 5 , which contains this linker, can be synthesized solvothermally as a twofold interpenetrated structure. Interestingly, when framework 5 is dipped in a solution of L₃ in DMF, linker substitution takes place as before, but linker L₅ now moves and diagonally binds two Zn^II centers to afford 6 as a nonpenetrated single framework. This linker place exchange reaction is unprecedented. All of these reactions take place in a single‐crystal to single‐crystal (SC‐SC) manner, and have been observed directly through X‐ray crystallography. In addition, each 3D framework undergoes complete copper(II) transmetalation.     

Paramagnetic Conducting Metal–Organic Frameworks with Three-Dimensional Structure

3D well-crystallized metal–organic frameworks (MOFs), M-THBQ (M=Fe, Co, Mn, THBQ=tetrahydroxybenzoquinone), are synthesized and characterized. Their structures are determined as cubic cell in the group of Pm from powder X-ray diffraction data, and their properties of electronic, magnetic and spectroscopic are also investigated. They are all semiconductors, and Fe-THBQ exhibits the air-stable n-type thermoelectric characteristic as its Seebeck coefficient reaches −130 μV K⁻¹, and the electrical conductivity is 2.7×10⁻⁴ S cm⁻¹ at 300 K. Additional, M-THBQ are paramagnetic, and the value of Weiss constant of Fe-THBQ is −219.37 K, indicating the existence of robust intramolecular antiferromagnetic exchanges. Meanwhile, they display strong absorption bands in the range of 220 to 1000 nm, suggest M-THBQ could have the potential to become photoabsorbers, and Fe-THBQ exhibits a narrow band gap of 0.63 eV according to the ultraviolet absorption edge spectrum.     

Covalent Organic Frameworks and Cage Compounds: Design and Applications of Polymeric and Discrete Organic Scaffolds

Porous organic materials are an emerging class of functional nanostructures with unprecedented properties. Dynamic covalent assembly of small organic building blocks under thermodynamic control is utilized for the intriguingly simple formation of complex molecular architectures in one‐pot procedures. In this Review, we aim to analyze the basic design principles that govern the formation of either covalent organic frameworks as crystalline porous polymers or covalent organic cage compounds as shape‐persistent molecular objects. Common synthetic procedures and characterization techniques will be discussed as well as more advanced strategies such as postsynthetic modification or self‐sorting. When appropriate, comparisons are drawn between polymeric frameworks and discrete organic cages in terms of their underlying properties. Furthermore, we highlight the potential of these materials for applications ranging from gas storage to catalysis and organic electronics.     

Post‐Synthetic Ligand Exchange in Zirconium‐Based Metal–Organic Frameworks: Beware of The Defects!

Post‐synthetic ligand exchange in the prototypical zirconium‐based metal–organic framework (MOF) UiO‐66 was investigated by in situ solution ¹H NMR spectroscopy. Samples of UiO‐66 having different degrees of defectivity were exchanged using solutions of several terephthalic acid analogues in a range of conditions. Linker exchange only occurred in defect‐free UiO‐66, whereas monocarboxylates grafted at defect sites were found to be preferentially exchanged with respect to terephthalic acid over the whole range of conditions investigated. A 1:1 exchange ratio between the terephthalic acid analogue and modulator was observed, providing evidence that the defects had missing‐cluster nature. Ex situ characterisation of the MOF powders after exchange corroborated these findings and showed that the physical‐chemical properties of the MOF depend on whether the functionalisation occurs at defective sites or on the framework.     

镁金属有机框架材料应用研究进展

镁金属有机框架材料（Mg-MOFs）作为一类高比表面积、结构可设计的多孔功能材料,有其独特的优势,其应用涉及到诸多领域,为镁资源的开发利用开拓了新领域,近年来受到了广大科研工作者的关注。本文阐述了Mg-MOFs在气体吸附与分离、电极材料、荧光传感、催化、染料吸附、药物传递六个方面的应用,提出了Mg-MOFs今后研究重点,并展望了其应用前景。     

溶剂交换法制备一维有机纳米材料

利用溶剂交换法制备了几种有机小分子化合物的一维纳米材料,并分别用SEM、TEM、XRD等对其结构进行了表征.分析了纳米材料的生长过程,讨论了有关的机理,并研究了其吸收光谱和荧光光谱等光物理行为.结果显示,有机纳米结构的形貌和尺寸对分子聚集体的光谱性质具有调制作用,使得它们展示出不同于溶液和体材料的优良纳米特性.     

Supramolecular Porphyrin‐Based Metal–Organic Frameworks with Fullerenes: Crystal Structures and Preferential Intercalation of C70

The syntheses and characterization of two new porphyrin‐based metal–organic frameworks (P‐MOFs), through the complexation of 5,10,15,20‐tetra‐4‐pyridyl‐21 H,23 H‐porphine (H₂TPyP) and copper(II) acetate (CuAcO) in the presence of the fullerenes C₆₀ or C₇₀ are reported. Complex 1 was synthesized in conjunction with C₆₀, and this reaction produced a two‐dimensional (2D) porous structure with the composition CuAcO‐CuTPyP?m‐dichlorobenzene (m‐DCB), in which C₆₀ molecules were not intercalated. Complex 2 was synthesized in the presence of C₇₀, generating a three‐dimensional (3D) porous structure, in which C₇₀ was intercalated, with the composition CuAcO‐CuTPyP?C₇₀?m‐DCB?CHCl₃. The structures of these materials were determined by X‐ray diffraction to identify the supramolecular interactions that lead to 2D and 3D crystal packing motifs. When a combination of C₆₀ and C₇₀ was employed, C₇₀ was found to be preferentially intercalated between the porphyrins.