水热合成新型硼磷酸盐化合物的研究进展

作为潜在的新型功能材料，硼磷酸盐近几年得到了科学家的极大重视。本文从结构化学角度对水热合成硼磷酸盐化合物进行了总结，并着重对过渡金属、P区主族元素和含有机模板硼磷酸盐化合物所具有的典型结构进行了描述和归类，同时还讨论了硼磷酸盐的最新研究进展及其发展方向。     

Cs2USi6O15: a tetravalent uranium silicate

A uranium(IV) silicate has been synthesized under high-temperature, high-pressure hydrothermal conditions. The structure consists of unbranched dreier single layers with the composition [Si(2)O(5)] that are connected by UO(6) octahedra to form a 3D framework with 7-ring channels where the Cs(+) cations are located. Each UO(6) octahedron spans four neighboring dreier single chains and, therefore, introduces a high degree of corrugation in the silicate layers. The U 4f X-ray photoelectron spectroscopy spectrum was measured to confirm the valence state of the uranium. A comparison of related metal silicate structures is made. After the synthesis of this compound, all members in the family of uranium silicates and germanates with oxidation states of uranium from 4+ to 6+ have been observed.     

Open-framework structures of transition-metal compounds

Inorganic framework solids are no longer limited to just the silicates and phosphates. Recent research has revealed that carboxylates, arsenates, sulfates, selenates, selenites, germanates, phosphites can also form such structures. One of the emerging areas combines the rich coordination chemistry of the central metal ions of many of these structures with the flexibility and functionality of the organic linkers to give rise to organic-inorganic hybrid compounds. The compounds of the transition-metals appear to provide many variations arising from their coordination preferences, ligand geometry, and the valence state. In addition, the combination of the magnetic nature of the transition metal center with the channel structure of open frameworks suggests interesting potential applications. In this Review the synthesis, structures and properties of the various transition-metal open-framework compounds are discussed.     

Crystalline oxyfluorinated open-framework compounds: Silicates, metal phosphates, metal fluorides and metal-organic frameworks (MOF)

This contribution is dedicated to a short overview on the utilization of fluorine for the preparation of crystalline microporous frameworks including different families of solids: zeolites, metal phosphates and metal-organic frameworks (MOF-type). Beside the silicates compounds, this presentation is focused on the different types of fluorinated aluminum or gallium phosphates hydrothermally obtained in the presence of organic structure-directing agent or templates. The structural features of aluminum fluorides synthesized with amines are also detailed as well as the influence of fluorine in the synthesis of the metal-organic frameworks involving trivalent metals. The role of fluorine is described for the hydrothermal synthesis of the different classes of materials. Fluorine is known for playing the role of mineralizing agent and favors the formation of well crystalline phases. The use of HF modifies the pH of the reaction, which allows for the insertion of additional metallic cations on the mineral network. From the structural point of view, fluoride anions can be located within small cavities of the 3D framework and interactions with metals T (T = Si, Al, Ga, …) are often observed, resulting in the coordination change (from tetrahedral unit TO₄ to trigonal bipyramid TO₄F or octahedron TO₄F₂). Several configurations are found for fluorine and it seems to favor the stabilization of the specific cubane-like building unit (D4R), in which it is trapped, or participates to the coordination sphere of the metal atoms with bridging or terminal bondings. In general, new three-dimensional topologies with extra-large pores are obtained. The synthesis of purely aluminum fluorides with structure-directing agent is considered but only molecular or low-dimensional structures (chain-like or layered) compounds have been described. Fluorine is also used as a mineralizing agent for the preparation of well crystalline porous aluminum or chromium carboxylates and it was observed to partly substitute the aquo ligands in the giant pore of the compound MIL-100.     

中孔分子筛MCM-41的合成与表征

以白炭黑和正硅酸乙酯为硅源,十二、十六烷基三甲基铵为模板剂,用水热法和室温直接法合成出中孔分子筛MCM-41,考察了对合成的影响因素,用红外光谱、吸附、孔分布、热分析等手段对这两种产物进行了表征。结果表明:这种分子筛可以在很宽的配比范围内获得,但较高水硅比更有利于合成;在水硅比较低的体系中得到了一种类MCM-41中孔相(亦应属于MCM-41),其XRD衍射峰较宽,2θ角度偏低,具有类似于无定形硅铝酸盐的骨架结构。     

手性多孔材料在色谱分离分析中的应用

手性多孔有机骨架材料(Chiral porous organic frameworks,CPOFs)具有孔性质优异、比表面积高、稳定性好以及易功能化等诸多优点,已经在手性催化、识别和分离等领域中得到应用。手性多孔有机骨架材料主要有手性金属-有机骨架材料(Chiral metal-organic frameworks,CMOFs)和手性共价有机骨架材料(Chiral covalent organic frameworks,CCOFs)及其他材料,这类材料具有特殊的手性识别、吸附作用,在色谱分离分析领域中已成为研究热点之一。该文综述了手性多孔材料的合成及其在色谱分离和选择性吸附中的应用,展望了未来CPOFs材料可能的应用与发展方向。     

Continuous flow synthesis of porous materials

Porous materials play an important role in chemical catalysis,separation and other industrial applications.High-efficiency preparation of porous materials has become an active research area.Conventional synthesis of porous materials has been dominated by one-pot solution processing conditions carried out by bulk mixing under conventional electric heating via hydrothermal,solvothermal or ionothermal reactions where high temperatures and pressures are the standard.Continuous flow synthesis has many key advantages in terms of efficient mass and heat transfer,precise control of residence times,improved opportunities for automation and feedback control of synthesis,scaling-up reactions and improved safety parameters compared to above mentioned conventional batch scale synthetic methods.In this review,continuous flow synthesis of various crystalline porous materials such as metal-organic frameworks(MOFs),covalent-organic frameworks(COFs),porous organic cages and zeolites is discussed.Combination of microfluidic methods with other techniques are also shown including various heating ways and various methods of substrate adding.     

Novel Coordination Polymers Constructed from 4,4'-Bipyridine and Phosphate

The synthesis of open-fiamework metal phosphates has been a subject of intense research owing to their interesting structural chemistry and potential applications as ionexchangers, catalysts and adsorbents. A large number of these materials are synthesized in the presence of organic amines as structure-directing agents. Recently, many research activities have focused on the synthesis of inorganic-organic hybrid frameworks. As compared with inorganic ligands, the advantage of using organic multidentate ligands is the efficacy of rational design of crystalline solids through their coordinating propensities and geometries.     

介孔分子筛的酸性和水热稳定性

介孔分子筛材料在催化、吸附与分离以及化学组装制备先进材料和分子器件等方面具有潜在的应用价值.但是,由于介孔分子筛材料较低的水热稳定性和较弱的酸性,极大地影响了其在催化研究中的广泛应用.本文系统地综述了最近几年在提高介孔分子筛酸性和水热稳定性的研究工作.其中包括:(1)将超酸组份负载于介孔分子筛的孔道中以达到提高介孔分子筛材料的酸强度的目的;(2)通过在合成介孔分子筛的过程中加入无机盐和有机胺等助剂或采用合适的后处理方法以提高介孔分子筛的水热稳定性;(3)通过新型模板剂来合成具有较高水热稳定性的介孔分子筛材料;(4)利用具有沸石分子筛基本结构单元的沸石分子筛导向剂与表面活性剂自组装来合成具有强酸中心和高温水热稳定的介孔分子筛材料.     

Recent Progress of Synthesis and Application in Au@MOFs Hybrid Materials

The combination of gold nanoparticles and metal–organic frameworks is one of the new directions of current research. It has applications in many aspects, especially as a catalyst for a variety of reactions. Therefore, this paper describes recent progress of synthesis and application in Au@MOFs hybrid materials.     

多孔有机骨架材料对顺式二醇化合物富集分离的研究进展

基于在碱性环境下硼酸能与顺式二醇化合物可逆共价结合形成稳定的五元或六元环酯,而在酸性环境下环酯开环释放顺式二醇化合物这一特性,设计合成高效、高选择性、高富集性能的硼亲和材料的研究备受关注。近年来,许多研究工作者合成了各种类型的硼亲和材料,应用于高选择性富集顺式二醇化合物。金属有机骨架(MOFs)和共价有机骨架(COFs)由于具有孔径可调、高孔隙率、高比表面积、骨架结构可调和化学及热稳定性良好等特点,被广泛应用于色谱分离和样品前处理领域。为赋予MOFs和COFs材料对顺式二醇化合物的富集选择性,各种不同结构和不同种类的硼酸修饰的MOFs和COFs被合成出来。该综述主要是对近几年来80余篇源于科学引文索引关于硼酸功能化MOFs和COFs的种类、合成方法及其应用文章的总结,包括“金属配体-片段共组装”“合成后修饰”和“自下而上”的硼酸功能化多孔材料的修饰策略,以及硼酸功能化MOFs和COFs的种类,介绍了其在化学分析和生物分析领域的发展概况和应用前景,客观评价了硼酸功能化MOFs和COFs的区别和优缺点。该文旨在让研究人员能够充分了解近几年硼酸功能化多孔有机骨架材料的研究现状、掌握合成思路和方法,为其应用提供一定的理论指导和技术支撑,为加快硼酸功能化多孔有机骨架材料的商业化脚步贡献绵薄之力。     

In situ hydrothermal synthesis of tetrazole coordination polymers with interesting physical properties

Tetrazole compounds have been studied for more than one hundred years and applied in various areas. Several years ago Sharpless and his co-workers reported an environmentally friendly process for the preparation of 5-substituted 1H-tetrazoles in water with zinc salt as catalysts. To reveal the exact role of the zinc salt in this reaction, a series of hydrothermal reactions aimed at trapping and characterizing the solid intermediates were investigated. This study allowed us to obtain a myriad interesting metal-organic coordination polymers that not only partially showed the role of the metal species in the synthesis of tetrazole compounds but also provided a class of complexes displaying interesting chemical and physical properties such as second harmonic generation (SHG), fluorescence, ferroelectric and dielectric behaviors. In this tutorial review, we will mainly focus on tetrazole coordination compounds synthesized by in situ hydrothermal methods. First, we will discuss the synthesis and crystal structures of these compounds. Their various properties will be mentioned and we will show the applications of tetrazole coordination compounds in organic synthesis. Finally, we will outline some expectations in this area of chemistry. The direct coordination chemistry of tetrazoles to metal ions and in situ synthesis of tetrazole through cycloaddition between organotin azide and organic cyano group will be not discussed in this review.     

Breakthrough and future: nanoscale controls of compositions,morphologies, and mesochannel orientations toward advanced mesoporous materials

Currently, ordered mesoporous materials prepared through the self‐assembly of surfactants have attracted growing interests owing to their special properties, including uniform mesopores and a high specific surface area. Here we focus on fine controls of compositions, morphologies, mesochannel orientations which are important factors for design of mesoporous materials with new functionalities. This Review describes our recent progress toward advanced mesoporous materials. Mesoporous materials now include a variety of inorganic‐based materials, for example, transition‐metal oxides, carbons, inorganic‐organic hybrid materials, polymers, and even metals. Mesoporous metals with metallic frameworks can be produced by using surfactant‐based synthesis with electrochemical methods. Owing to their metallic frameworks, mesoporous metals with high electroconductivity and high surface areas hold promise for a wide range of potential applications, such as electronic devices, magnetic recording media, and metal catalysts. Fabrication of mesoporous materials with controllable morphologies is also one of the main subjects in this rapidly developing research field. Mesoporous materials in the form of films, spheres, fibers, and tubes have been obtained by various synthetic processes such as evaporation‐mediated direct templating (EDIT), spray‐dried techniques, and collaboration with hard‐templates such as porous anodic alumina and polymer membranes. Furthermore, we have developed several approaches for orientation controls of 1D mesochannels. The macroscopic‐scale controls of mesochannels are important for innovative applications such as molecular‐scale devices and electrodes with enhanced diffusions of guest species. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 321–339; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.200900022     

Two stable 3D metal-organic frameworks constructed by nanoscale cages via sharing the single-layer walls

Two stable 3D metal-organic frameworks are constructed by the hydrothermal reactions of Cd(NO3)2.4H2O and IDC3- using bpy and Bu4NBr as templates. Both structures show the same frameworks, which are composed by the nanoscale cages via sharing the single-layer walls.     

使用四乙基氢氧化铵作为有机模板剂和常规硅铝源直接合成SSZ-13沸石分子筛

使用四乙基氢氧化铵作为有机模板剂, 利用常规铝源和硅源而不需要高硅Y沸石作为起始原料, 同时加入适量的沸石晶种直接合成了SSZ-13沸石分子筛. 所合成的沸石产物结晶度好, 具有良好的水热稳定性, 并在氨选择性催化还原(NH₃-SCR)反应中显示出优异的催化性能, 为其在工业上广泛应用提供了可能.     

大环Schiff碱希土配合物的合成及表征

大环化合物及其配合物的研究近来十分活跃,模板反应是合成新型大环配合物的主要手段。通常采用主族金属元素及过渡金属元素离子作模板,而用Ln~(3+)作模板则较少见。本文用自制的呋喃二甲醛—2,5为原料,以Ln~(3+)为模板,合成并表征了一系列大环配合物。     

Porous metal-organic frameworks as platforms for functional applications

Metal-organic frameworks (MOFs), also known as coordination polymers, have emerged as a new class of crystalline porous materials, which are constructed from metal ions or metal ion clusters and bridging organic linkers. MOFs have tunable pores and functionalities, and usually exhibit very high surface areas. The potential applications of porous MOFs cover a broad range of fields and most of their applications are related to pore sizes, shapes and structures/environments. In this feature article, we provide an overview of the recent developments of porous MOFs as platforms in the functional applications of sorption and separation, heterogeneous catalysis, as supports/host matrices for metal nanoparticles, and as templates/nanoreactors for new material preparation.     

A simple and general method for the synthesis of multicomponent Na2V6O16.3H2O single-crystal nanobelts

Multicomponent Na2V6O16.3H2O (barnesite) single-crystalline nanobelts were synthesized by a direct reaction-crystallization growth of bulk V2O5 and NaF powders under hydrothermal treatment without using any templates or catalysts. This new strategy could be extended to prepare other one-dimensional multicomponent nanomaterials including ammonium, alkali-metal or alkali-earth metal vanadium oxide bronzes and other transition metal oxyfluorides. This is an efficient and mild solution method with clear advantages over the traditional high-temperature approach for the large-scale production of 1D multicomponent nanomaterials. The applicability of this approach toward the preparation of other inorganic systems, such as tungstates and molybdates, will be explored.     

Metal–Organic Frameworks-Derived Self-Supported Carbon-Based Composites for Electrocatalytic Water Splitting

Electrocatalytic water splitting has been considered as a promising strategy for the sustainable evolution of hydrogen energy and storage of intermittent electric energy. Efficient catalysts for electrocatalytic water splitting are urgently demanded to decrease the overpotentials and promote the sluggish reaction kinetics. Carbon-based composites, including heteroatom-doped carbon materials, metals/alloys@carbon composites, metal compounds@carbon composites, and atomically dispersed metal sites@carbon composites have been widely used as the catalysts due to their fascinating properties. However, these electrocatalysts are almost powdery form, and should be cast on the current collector by using the polymeric binder, which would result in the unsatisfied electrocatalytic performance. In comparison, a self-supported electrode architecture is highly attractive. Recently, self-supported metal–organic frameworks (MOFs) constructed by coordination of metal centers and organic ligands have been considered as suitable templates/precursors to construct free-standing carbon-based composites grown on conductive substrate. MOFs-derived carbon-based composites have various merits, such as the well-aligned array architecture and evenly distributed active sites, and easy functionalization with other species, which make them suitable alternatives to non-noble metal-included electrocatalysts. In this review, we intend to show the research progresses by employment of MOFs as precursors to prepare self-supported carbon-based composites. Focusing on these MOFs-derived carbon-based nanomaterials, the latest advances in their controllable synthesis, composition regulation, electrocatalytic performances in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting (OWS) are presented. Finally, the challenges and perspectives are showed for the further developments of MOFs-derived self-supported carbon-based nanomaterials in electrocatalytic reactions.     

Catalytic Oxidation of Alcohols and Amines to Value‐Added Chemicals using Water as the Solvent

Designing reactions in aqueous media has been one of the major challenges in modern organic synthesis, especially to avoid the use of large amounts of organic solvents whose disposal is a matter of grave concern from an environmental perspective. The oxidation of alcohols and amines is an essential and important step in the synthesis of many valuable products including polymers and pharmaceuticals. In recent times, there has been a surge in the use of water as a solvent in many organic reactions. This review focuses specifically on the oxidation reactions of alcohols and amines carried out in water media using transition metal catalysts, metal‐free catalysts and photocatalysts.