首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
金属有机骨架(MOFs)是由含氧、氮等的多齿有机配体(大多是芳香多酸和多碱)与过渡金属离子自组装而成的配位聚合物,本文对该材料在气体吸附、电化学、催化、载药材料等方面的应用进行了介绍。  相似文献   

2.
氮唑类金属配合物是含能材料中研究较为广泛的一类材料,其结构易于调控,且具有高能低感的特性。本文选用1,2,4-三氮唑、四氮唑和5-氨基四氮唑这三类配体,与Zn2+、Cd2+、Cu2+等金属离子合成得到系列金属有机骨架结构,并对这些物质进行了热重、差热分析和燃烧热性能测试,结果表明金属离子参与配位后,氮唑类配合物的热稳定性得到了明显增强,其密度也随之增加,而热能数据表明合适的金属离子与含能配体参与配位能有效提高含能配合物的标准摩尔生成焓,金属离子与有机配体的配位聚集程度对生成焓有一定的影响作用,这对今后如何选择合适的金属离子与含能配体进行含能配合物的合成具有指导意义.  相似文献   

3.
Recent progress in the research of radical anion ligands and their complexes with metals were summarized in this review. Radical anions were sorted into several types including iminosemiquinonate and iminoquinonate radical, nitroxide radical, heterocycle radical etc. Structural characteristics and properties of the corresponding complexes were introduced. The complexes exhibited novel properties and possibility for applications in organic magnetic materials and transition metal catalysis.  相似文献   

4.
Cucurbit[n]urils (Q[n]) are promising ligands for the coordination of metal ions, metal complexes or clusters, and form various Q[n]-based complexes. Among the Q[n] complexes, those formed by direct coordination between Q[n]s and metal ions are partic- ularly important. The direct coordination of metal ions to cucurbit[n]urils leads to the formation of Q[n]-based molecular capsules, tubular polymers and molecular bracelets, which could have nanoscale applications in drug delivery, molecular devices and new materials.  相似文献   

5.
Seo JS  Whang D  Lee H  Jun SI  Oh J  Jeon YJ  Kim K 《Nature》2000,404(6781):982-986
Inorganic zeolites are used for many practical applications that exploit the microporosity intrinsic to their crystal structures. Organic analogues, which are assembled from modular organic building blocks linked through non-covalent interactions, are of interest for similar applications. These range from catalysis, separation and sensor technology to optoelectronics, with enantioselective separation and catalysis being especially important for the chemical and pharmaceutical industries. The modular construction of these analogues allows flexible and rational design, as both the architecture and chemical functionality of the micropores can, in principle, be precisely controlled. Porous organic solids with large voids and high framework stability have been produced, and investigations into the range of accessible pore functionalities have been initiated. For example, catalytically active organic zeolite analogues are known, as are chiral metal-organic open-framework materials. However, the latter are only available as racemic mixtures, or lack the degree of framework stability or void space that is required for practical applications. Here we report the synthesis of a homochiral metal-organic porous material that allows the enantioselective inclusion of metal complexes in its pores and catalyses a transesterification reaction in an enantioselective manner. Our synthesis strategy, which uses enantiopure metal-organic clusters as secondary building blocks, should be readily applicable to chemically modified cluster components and thus provide access to a wide range of porous organic materials suitable for enantioselective separation and catalysis.  相似文献   

6.
Copper(Ⅰ) complexes are attractive photo-functional materials due to their rich photochemical and photophysical properties. It has been proved that these new materials have potential application in many fields, such as organic light-emitting diodes, optical sensor, nonlinear optics and dye sensitized solar cells. The goal of this review is to outline the progress in this field. Many aspects, including new ligands, stereochemical control and the construction of supramolecules, design of the excited states, the high-energy emission and low-energy emission, the Cu-Cu bonding interactions and applications, are discussed.  相似文献   

7.
联吡啶/邻菲咯啉(bpy/phen)类配体被广泛应用于金属配位的均相有机催化反应.将金属修饰的联吡啶/邻菲咯啉(M(bpy)/M(phen))活性中心固定在多孔载体中,可以有效提升催化效果,即拥有了均相催化剂的活性,也兼顾了主体材料的非均质性.文章综述了M(bpy)/M(phen)功能化金属有机框架(MOFs)的最新研究进展,并对以金属锆(Zr)为结点的具有三维拓扑结构的UiO-67型MOFs材料(MOF UiO-67)展开分析.文章详细介绍了这些多孔材料的合成方法,以及它们在热力学催化、光催化和电催化方面的催化性能.  相似文献   

8.
Mal NK  Fujiwara M  Tanaka Y 《Nature》2003,421(6921):350-353
Since the discovery of MCM-41 more than ten years ago, many investigations have explored the suitability of hexagonal mesoporous silicas for potential practical applications. These range from catalysis and optically active materials to polymerization science, separation technology and drug delivery, with recent successes in the fabrication of hybrid mesoporous organosilicas expected to open up further application possibilities. Because the pore voids of this class of materials exhibit relatively narrow pore size distributions in the range of 2-4 nm in diameter, mesoporous silicas can selectively include organic compounds and release them continuously at a later stage. The functionalization of MCM-41 pore voids with photoactive derivatives provides influence over the material's absorption behaviour, but full control over the release process remains difficult. Here we show that the uptake, storage and release of organic molecules in MCM-41 can be regulated through the photocontrolled and reversible intermolecular dimerization of coumarin derivatives attached to the pore outlets. Successful functionalization requires uncalcined MCM-41 still filled with the template molecules that directed the formation of its pores, to ensure that coumarin derivatives attach preferentially to the pore outlets, rather than their inside walls. We find that this feature and the one-dimensional, isolated nature of the individual pores allow for efficient and reversible photocontrol over guest access to the material's interior.  相似文献   

9.
MXene是一种新型的二维过渡金属碳化物或碳氮化物,具有类似石墨烯的二维结构.MXene因其独特的物理和化学特性,以及在储能、催化、电子与光电子等领域中的良好应用前景而受到广泛关注.介绍了MXene材料的制备、表征以及在锂离子电池、钠离子电池、锂硫电池和超级电容器等储能器件上的最新研究成果.最后,对MXene材料的未来发展和挑战进行了介绍.  相似文献   

10.
Controlling anisotropic nanoparticle growth through plasmon excitation   总被引:1,自引:0,他引:1  
Jin R  Cao YC  Hao E  Métraux GS  Schatz GC  Mirkin CA 《Nature》2003,425(6957):487-490
Inorganic nanoparticles exhibit size-dependent properties that are of interest for applications ranging from biosensing and catalysis to optics and data storage. They are readily available in a wide variety of discrete compositions and sizes. Shape-selective synthesis strategies now also yield shapes other than nanospheres, such as anisotropic metal nanostructures with interesting optical properties. Here we demonstrate that the previously described photoinduced method for converting silver nanospheres into triangular silver nanocrystals--so-called nanoprisms--can be extended to synthesize relatively monodisperse nanoprisms with desired edge lengths in the 30-120 nm range. The particle growth process is controlled using dual-beam illumination of the nanoparticles, and appears to be driven by surface plasmon excitations. We find that, depending on the illumination wavelengths chosen, the plasmon excitations lead either to fusion of nanoprisms in an edge-selective manner or to the growth of the nanoprisms until they reach their light-controlled final size.  相似文献   

11.
近年来窄带隙溶胶半导体纳米晶引起人们极大关注,该类纳米晶在光学、电学、生物医疗、材料科学等其他领域有着非常重要的应用.大量研究证实了Ag_2S量子点具有许多优异性能,比如:近红外荧光发射、低毒性、荧光量子效率高、稳定性好、成本低和合成设备简单.与传统的量子点(含有重金属Cd,Hg,Pb元素)相比,近红外发光的Ag_2S量子点避免了重金属离子本身固有的毒性,并且因其具有低毒性被用在生物医疗中.在本文中详细讨论了半导体发光Ag_2S量子点的性质、晶体结构和合成方法,并对Ag_2S量子点的生物相容性评价方法以及在生命科学领域的应用进行了阐述.  相似文献   

12.
合成了N,N’-双(8-羟基喹啉基-5-亚甲基)哌嗪,并与铝离子配位形成了新颖的超支化配位聚合物,进而自组装成了球形纳米粒子.超支化聚合物的结构和纳米粒子的形态分别通过ESI-MS和TEM证实.粒子的大小及其分布通过测量TEM照片上的数百个粒子得到,结果表明粒子的大小分布较窄.同时发现纳米粒子形成依赖于配体和铝离子的比例.我们测定了这种配位聚合物纳米粒子的光致发光性质,并对结果进行了讨论.  相似文献   

13.
微孔有机聚合物是一种新型的多孔材料,在非均相催化、吸附、分离和气体存储等方面具有潜在的应用.它是最近几十年发展起来的,全部由有机分子的构建块组装而成的微孔(孔径小于2.0nm)固体.依据设计策略的不同,主要可以分成以下4种:(1)通过交联反应阻止链密堆积的超交联聚合物;(2)通过刚性和扭曲基团阻止链密堆积的自具微孔聚合物;(3)通过大共轭?-体系刚性结构组建的共轭微孔聚合物;(4)通过适宜的官能团发生可逆地缩合反应来制备的共价有机骨架聚合物.本文根据国内外的研究背景,重点介绍自具微孔聚合物和共轭微孔聚合物.  相似文献   

14.
 固定化金属离子亲和色谱是将过渡金属离子通过配体螯合在固相基质上,通过过渡金属离子与靶分子的组氨酸或半胱氨酸特异性结合形成相对稳定的复合物,最后以竞争性洗脱方式实现靶分子的富集与纯化,其核心为金属螯合亲和基质材料制备。具有亲和选择性高、生物兼容性好、可逆再生等优势,迄今已发展了40余年,广泛应用于靶分子的特异性富集、分离与纯化,本文综述了近3年固定化金属离子亲和色谱纳米材料、微球色谱基质、棉纤维、分子印迹材料、整体材料、共价有机骨架等方面的研究进展。  相似文献   

15.
研究了海水中铜和锌与天然有机质、胡敏酸和聚生角毛藻分泌物等的相互作用。表明,在天然海水介质(pH 8.0)中,这些有机质能与游离的铜和锌离子络合,生成 ASV不稳定的和非 ASV不稳定的金属-有机质形态。用阳极溶出伏安滴定法确定了铜-有机质、锌-有机质的络合容量及其条件稳定常数。  相似文献   

16.
Introduction Ionic liquids (ILs) are proving to be increasingly inter-esting fluids for application in soft-matter materialssystems from electrochemistry to energetic materialsand are also studied as potential solvents in separationprocesses[1-19]. Proper…  相似文献   

17.
邻位碳硼烷o-C2B10H12中CH单元上的H原子具有一定的弱酸性,可以和强碱n-BuLi反应,生成含有金属离子的盐,该盐再与硫族元素发生插入反应,形成锂盐Li2E2C2B10H10(E=S,Se),据此可以生成半夹芯16e碳硼烷有机金属化合物。这些半夹芯16e碳硼烷有机金属化合物金属中心电子的不饱和性,两个M-E键具有一定的化学活性,以及碳硼烷笼子中的B(3)/B(6)位的B-H键能够被活化,可以控制在不同的反应条件下与一系列供电子配体发生反应,生成许多结构新颖的产物。本文综述了半夹芯16e碳硼烷有机金属化合物的反应性研究进展。  相似文献   

18.
The applications of monodisperse colloidal silica particles are constantly extended because of their uniformity in morphology and size as well as their easily-modified surface properties. This review summarizes the research progress made by the author and co-workers on the formation conditions and mechanism of monodisperse system and the applications in various fields such as particle analysis, chromatography, catalysis, optical physics, and intelligent materials.  相似文献   

19.
咪唑基配位聚合物   总被引:3,自引:0,他引:3  
含咪唑基配体的配位聚合物,有其独特的光学、磁性、催化和生物活性,并具备配合物和复合高分子的特点,在应用新材料、分子识别和自组装等方面有广阔的应用前景。本就咪唑基有机配体中连接咪唑的有机基团的差异,对含咪唑基配体的配位聚合物进行了分类研究。  相似文献   

20.
论文根据笔者课题组的近期工作,对双光子活性配合物的设计合成及其在生物学中的应用的探索,按照不同金属分类进行了综述.以其生物学应用为导向,利用配合物的结构特点,有机配体的可设计性强,金属离子的选择性广,设计合成了一系列双光子活性高、生物相容性好的配合物.实验结合理论系统地研究了配合物结构-性质相关性,探索了配合物光功能材料在生物学方面的应用.对配合物材料在生物学方面的应用进行了展望.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号