两个基于八钼酸盐的无机-有机杂化材料的合成、结构和光催化性能

通过水热法成功合成了两个新的基于(β-Mo₈O₂₆)^4-构型的无机-有机杂化材料,分子式分别为{[Ni(β-Mo₈O₂₆)(H₂O)₄](H₂Fbix) 2H₂O}_n(1)和{[Co(β-Mo₈O₂₆)(H₂O)₄](H₂Fbix) 2H₂O}_n(2)(Fbix=2,3,5,6-四氟-二(1,4-咪唑-1-甲基)苯)。利用X-射线单晶衍射、X-射线粉末衍射、红外光谱、热重分析和元素分析等对该化合物的结构和性能进行了表征。晶体结构分析表明：化合物1和2为同构化合物。在化合物1中,扭曲八面体构型的Ni^II与两个β-[Mo₈O₂₆]^4-单...     

基于5-羟甲基-1.3-苯二酸的两个四连接锌配合物的合成、结构和性质

在辅助配体4,4′-二(1H-咪唑-1-基)-1,1′-双苯（4,4′-DIB）的帮助下,5-羟甲基-1.3-苯二甲酸(H₂HIA)与Zn(BF₄)₂通过溶剂热或者水热反应构建出了两个具有sql网络的三维超分子配合物,即{[Zn₂(HIA)₂(4,4′-DIB)₂]·xGuest}_n (1, CCDC: 1989855 )和[Zn₂(HIA)₂(4,4′-DIB)₂]_n(2, CCDC: 1989856)。并对配合物的PXRD, IR, TGA和荧光等特性进行了表征。     

水合铵硼氧酸盐及其饱和溶液的FTIR和Raman光谱研究

研究了NH₄B₅O₈·4H₂O和(NH₄)₂B₈O₁₃·6H₂O及其饱和溶液于20℃的FTIR和Raman光谱,对振动频率进行了归属.根据振动光谱特征,预测(NH₄)₂B₈O₁₃·6H₂O中所含基本结构单元为[B₇O ₁₁(OH)·B(OH)₃]^2-.首次将Raman光谱中516cm^-1处的强散射峰归属为这一多聚硼氧配阴离子的对称脉冲振动峰,并对以上2种铵硼氧酸盐饱和溶液中硼氧配阴离子的存在形式{B(OH)₃,[B₃O₃(OH)₄]^-和[B₅O₆(OH)₄]^-}和相互作用机理进行了探讨.     

基于三联吡啶-4-羧酸的系列配合物的结构多样性和发光性质（英文）

在溶剂热条件下制备了系列新配合物：[Cr₂(tpc)₂(HCOO)₂(OH)₂]·4H₂O (1)、[Ba(tpc)₂(H₂O)₂]_n (2)、[Zn₂(tpc)₂(NO₃)₂]_n (3)、[Pb(Htpc)(NO₃)₂]·2H₂O (4)和[Rh(Htpc)Cl₃]·CH₃OH·H₂O (5)(Htpc=2,2′∶6,2″-三联吡啶-4-羧酸)。X射线单晶衍射分析表明,有机配体呈4种不同的配位方式;配合物1～5通过C—H…O/N氢键和π…π相互作用形成了新颖的超分子网络。研究了这些配合物的发光性能。在365 nm紫外辐射下,晶体2～5分别呈现绿色、蓝色...     

新型含氮配体钴配合物的水热合成、晶体结构及荧光性质

以4,5-二羟基苯-1,3-二磺酸钠（Na₂H₂L）和4,4′-bipy为原料,采用水热法与Co(NO₃)₂反应合成了新的含氮配体钴配合物[Co(4,4′-bipy)(H₂O)₄]·H₂L·2H₂O（1）（H₂L^2-=4,5-二羟基苯-1,3-二磺酸根离子,4,4′-bipy=4,4′-联吡啶）,其结构和组成经X-射线单晶衍射、红外光谱、元素分析和热重分析表征。晶体结构解析表明：钴离子与4,4′-bipy和水分子配位,形成扭曲的八面体配位构型。H₂L^2-配体没有配位,仅起平衡电荷作用。在结构单元中,[Co(4,4′-bipy)(H₂O)₄]²⁺, H₂L^2-和自由水分子之间通过氢键相连。配合物的荧光发射峰与配体相比发生了蓝移,最大发射峰位于357 nm。     

新型链状镍配合物的水热合成及其性质

采用水热法合成了一种新型的镍配合物{\[Ni(bipy)(H₂O)₄]·(H₂Dhbs)₂·(H₂O)₄}_n（H₂Dhbs=2,5-二羟基苯磺酸，bipy=4,4′-联吡啶），其结构和性能经FL， IR，元素分析，X-射线单晶衍射和TG表征。结果表明：bipy与镍离子配位，形成链状结构。H₂Dhbs-配体没有参与配位，仅起平衡结构电荷的作用。在结构单元中，\[Ni(bipy)(H₂O)₄]²⁺， H₂Dhbs^-和自由水分子之间通过氢键连接。与配体相比，配合物的荧光发射峰发生了红移，最大发射峰位于464 nm，荧光寿命为2.081 7 ms。     

双甲基化大豆苷元磺酸盐的合成、晶体结构及活性研究

以大豆苷元为原料合成了强水溶性异黄酮类化合物7,4′-二甲氧基异黄酮-3′-磺酸钠(1)和7,4′-二甲氧基异黄酮-3′-磺酸铜(2).X射线单晶衍射分析表明,化合物1的分子组成为[Na(H₂O)₂](C₁₇H₁₃O₄SO₃),Na的配位数为6,且相邻钠离子以7,4′-二甲氧基异黄酮-3′-磺酸根氧原子桥连,与两个磺酸根的3个氧原子和1个S原子组成六元环,六元环通过Na-O配位键彼此稠合,在晶体结构中形成延伸的锯齿状聚合八面体配位钠离子链;这些钠离子链之间又通过配位水与配位水、磺酸根之间的氢键作用自组装成二维结构的超分子离子聚合物.化合物2的分子组成为[Cu(H₂O)₆](C₁₇H₁₃O₄SO₃)₂·8H₂O,Cu(Ⅱ)位于对称中心上.[Cu(H₂O)₆]²⁺,C₁₇H₁₃O₄SO^-₃和H₂O之间存在多种氢键;并且异黄酮环反平行排列存在π…π的堆积作用.氢键和π…π的堆积作用使化合物2自组装成三维结构的超分子.抗缺氧缺血活性试验结果表明,它们的抗缺氧缺血活性比大豆苷元的高.     

过渡金属-联咪唑-Dawson型钨磷酸盐杂化化合物的酶固定化性能

利用水热法和直接沉淀法, 设计合成了5例由过渡金属(TM)-联咪唑配阳离子与Dawson型钨磷酸阴离子构成的多金属氧酸盐(POM)基有机-无机杂化化合物[Ni(H₂biim)₃]₄[Ni(H₂biim)₂(P₂W₁₈O₆₂)₂]·2H₂O(1), [Co^III(H₂biim)₃]₂[P₂W₁₈O₆₂]·8H₂O(2), [Cu(H₂biim)₂]₃[P₂W₁₈O₆₂]·4H₂O(3), [Co^II(H₂biim)₃]₂H₂[P₂W₁₈O₆₂]·9H₂O(4)和 [Ni(H₂biim)₃]₃[P₂W₁₈O₆₂]·2H₂O(5); 并利用X射线单晶衍射分析(SC-XRD)、 红外光谱(IR)和热重-差热分析 (TG-DTA)等对其进行了表征. 化合物1~5作为载体用于固定辣根过氧化物酶(HRP)时, 显示出了较高的酶固定化能力. 另外, 利用圆二色光谱(CD)和激光扫描共聚焦显微镜(LSCM)等方法评价了固定化酶HRP/1~HRP/5的重复使用性、 储存稳定性和检测过氧化氢(H₂O₂)的性能. 由于该类POMs与HRP间存在强的相互作用, 利用简单的物理吸附法即可实现POMs对HRP的固载. POMs对酶的固定不但提高了HRP对使用及储存环境的耐受性, 同时也拓展了POMs在酶固定化领域的应用.     

系列Co-M(M=Cd,Zn, Co)配位聚合物的合成、结构及光电性能

采用水热合成方法得到了3个Co-M配聚物: [CoCd(mal)₂(H₂O)₄]_n(1), [CoZn(mal)₂(H₂O)₄]_n(2) 和[Co₂(mal)₂(H₂O)₄]_n(3)(mal=malonate). 通过X射线单晶衍射确定了各配聚物的结构. 3个配聚物都是由丙二酸构筑并具有2D层状结构, 通过氢键进一步将2D层网联成3D无限网络结构. 通过表面光电压谱(SPS)对3个配聚物的表面光电性能进行了重点研究, 并与其相应的UV-Vis吸收光谱进行了对比. 结果表明, 这3个配聚物在300~600 nm范围内均表现出正的光伏响应, 而且SPS和UV-Vis光谱之间具有较好的对应关系.     

铜配合物修饰的Dawson型钨磷酸盐的合成、晶体结构和催化性能

在水热条件下,Cu(Ⅱ)-H₂biim配合物与Dawson型钨磷酸盐构筑了1个无机-有机杂化化合物[Cu(H₂biim)₂(H₂O)][{Cu(H₂biim)₂}₂(P₂W₁₈O₆₂)]·11H₂O(1)(H₂biim=2,2'-联咪唑)。 通过单晶X射线衍射、红外光谱(IR)、X射线粉末衍射(XRD)、元素分析、电化学分析等技术手段对其进行了表征。 结构分析表明,在化合物1分子中,[P₂W₁₈O₆₂]^6-单元作为双齿配体与2个Cu²⁺离子配位形成双支撑的杂多阴离子[{Cu(H₂biim)₂}₂(P₂W₁₈O₆₂)]^2-,在其外部有1个游离的[Cu(H₂biim)₂(H₂O)]²⁺ 和11个H₂O分子。 H₂biim分子与杂多阴离子/H₂O分子间存在氢键,通过氢键、静电和π-π堆积作用,进一步构成具有3D结构的晶体材料。 该晶体化合物对H₂O₂和NaNO₂的还原具有良好的电催化作用;同时,作为酸催化剂用于合成环己酮乙二醇缩酮反应,催化活性高,可重复使用。     

H2 storage in isostructural UiO-67 and UiO-66 MOFs

The recently discovered UiO-66/67/68 class of isostructural metallorganic frameworks (MOFs) [J. H. Cavka et al. J. Am. Chem. Soc., 2008, 130, 13850] has attracted great interest because of its remarkable stability at high temperatures, high pressures and in the presence of different solvents, acids and bases [L. Valenzano et al. Chem. Mater., 2011, 23, 1700]. UiO-66 is obtained by connecting Zr(6)O(4)(OH)(4) inorganic cornerstones with 1,4-benzene-dicarboxylate (BDC) as linker resulting in a cubic MOF, which has already been successfully reproduced in several laboratories. Here we report the first complete structural, vibrational and electronic characterization of the isostructural UiO-67 material, obtained using the longer 4,4'-biphenyl-dicarboxylate (BPDC) linker, by combining laboratory XRPD, Zr K-edge EXAFS, TGA, FTIR, and UV-Vis studies. Comparison between experimental and periodic calculations performed at the B3LYP level of theory allows a full understanding of the structural, vibrational and electronic properties of the material. Both materials have been tested for molecular hydrogen storage at high pressures and at liquid nitrogen temperature. In this regard, the use of a longer ligand has a double benefit: (i) it reduces the density of the material and (ii) it increases the Langmuir surface area from 1281 to 2483 m(2) g(-1) and the micropore volume from 0.43 to 0.85 cm(3) g(-1). As a consequence, the H(2) uptake at 38 bar and 77 K increases from 2.4 mass% for UiO-66 up to 4.6 mass% for the new UiO-67 material. This value is among the highest values reported so far but is lower than those reported for MIL-101, IRMOF-20 and MOF-177 under similar pressure and temperature conditions (6.1, 6.2 and 7.0 mass%, respectively) [A. G. Wong-Foy et al. J. Am. Chem. Soc., 2006, 128, 3494; M. Dinca and J. R. Long. Angew. Chem., Int. Ed., 2008, 47, 6766]. Nevertheless the remarkable chemical and thermal stability of UiO-67 and the absence of Cr in its structure would make this material competitive.     

UiO-66 and hcp UiO-66 Catalysts Synthesized from Ionic Liquids as Linker Precursors

Using ionic liquids (ILs) as linker precursors, the well-known metal-organic framework (MOF) UiO-66 (Universitetet i Oslo) and the recently reported MOF hcp UiO-66 (hexagonal closed packed) have been successfully synthesized and characterized. The advantage of the applied novel synthesis approach is an economically and environmentally benign work-up procedure, due to the better solubility of the IL. Additionally, the reactivity of the terephthalate anions is increased compared to terephthalic acid, resulting in faster MOF formation with an increased amount of defects in the MOF structure. In order to explore to the influence of defects on the catalytic performance, the cyclisation of citronellal to isopulegol was employed as test reaction. The activity of hcp UiO-66 and fcc UiO-66 (face centered cubic) is improved compared to other MOF or zeolite based catalysts, while the selectivity is similar.     

Crystal structure and MAS-NMR study of rehydrated UiO-7

The framework of rehydrated UiO-7 has the ZON type of topology. The crystal structure is described on the basis of high resolution, synchrotron powder X-ray diffraction data. The chemical composition of the unit cell is Al₃₂P₃₂O₁₂₈·62H₂O. Its dimensions are a=14.4930(2), b=14.8731(2) and c=17.5738(3) Å; space group Pbca. Of the four non-equivalent Al atoms, two have normal tetrahedral coordination, whereas one obtains five-coordination and one achieves octahedral coordination on additional bonding to three non-equivalent water molecules. Six more water molecules are located in the channels and are interconnected via hydrogen bonds. These features were confirmed by solid-state ²⁷Al MAS NMR data. Site assignment of ³¹P signals is discussed on the basis of POAl angles and Al-coordination.     

高稳定性金属有机骨架UiO-66的合成与应用

金属有机骨架(metal-organic frameworks,MOFs)是一种由金属中心与有机配体自组装而成的、具有三维网状有序孔结构的新型多孔晶体材料,其具有超高的比表面积、种类和结构多样性、可化学功能化等特点,在多个研究领域显示出了潜在的应用前景,已成为当前化学、材料学科的研究热点之一。 然而大多数MOFs材料的稳定性较差,极大地束缚了MOFs材料的发展。 以Zr为金属中心,对苯二甲酸为有机配体的UiO-66具有较好的热稳定性,结构可在500 ℃保持稳定,并且其还具有很高的耐酸性和一定的耐碱性,引起了人们的关注。 本文主要综述了UiO-66在合成调控、功能化合成和后改性方面的研究现状,以及其在吸附和催化等领域的应用前景。     

螺吡喃功能化UiO-66光响应吸附剂的制备及其性能

将光响应分子甲基螺吡喃SP-CH₃引入UiO-66的非极性孔笼中,构筑吸附活性位可光控调节的光响应吸附剂。SP-CH₃功能化的吸附剂完好保留了载体UiO-66的骨架和孔道结构。以阴离子染料甲基橙为探针,研究了吸附剂在不同光照条件下的吸附和解吸性能。结果表明,经紫外光照后,吸附剂对甲基橙的吸附量为41.99 mg·g^-1,相较于可见光照后样品的吸附量提升57.56%,吸附作用增强;经可见光照后,甲基橙的脱附量为81.6%。本策略通过光照刺激改变UiO-66孔笼中SP-CH₃的构型及表面电荷性质,即对吸附活性位进行光控调节,在不同光照条件下实现对吸附质的高效吸附和有效脱附。     

Molecular dynamics simulation study of drugs adsorption in UiO-66

Metal-organic frameworks (MOFs) are novel porous materials that have been extensively used in sensors, catalysis, gas storage and separation, and drug deliver owing to their adjustable pore size, large surface area and high porosity. Among diverse MOFs, UiO-66 can be a promising carrier for drug delivery due to high porosity and chemical stability. However, the adsorption mechanism of drugs in UiO-66 has not been identified and need a further investigation. Hence, we utilized molecular dynamic (MD) simulation to investigate the adsorption mechanism of UiO-66 as drug carriers. The MD simulation of UiO-66 exhibits the busulfan loading of 80 %, ibuprofen of 20 % and 5-fluorouracil of 30 %, respectively. We also demonstrated that the host-guest interaction between UiO-66 and drugs is dominated by the Van der Waals force. UiO-66 shows the highest affinity for busulfan compared with ibuprofen and 5-fluorouracil. In addition, it is certified the linear relation between the adsorption atoms and the interaction energy, which could help us to predict the interaction energy between drugs and UiO-66 by the contact atoms.     

Facile Synthesis and Properties of UiO-66 Electrode Material for Supercapacitors

A block-like metal-organic framework UiO-66 was prepared by in-situ growth one-pot hydrothermal process. The as-synthesized material was characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The electrochemical properties used as a supercapacitor electrode material were evaluated by cyclic voltammetry(CV), galvanostatic charge-discharge measurement(GCD) and electrochemical impedance spectroscopy(EIS) in 2 M KOH solution, exhibiting a high specific capacitance(311 F·g~(-1) at 1 A·g~(-1)), suggesting its promising potential as a supercapacitor electrode material.     

螺吡喃功能化UiO-66光响应吸附剂的制备及其性能

将光响应分子甲基螺吡喃SP-CH₃引入UiO-66的非极性孔笼中,构筑吸附活性位可光控调节的光响应吸附剂。SP-CH₃功能化的吸附剂完好保留了载体UiO-66的骨架和孔道结构。以阴离子染料甲基橙为探针,研究了吸附剂在不同光照条件下的吸附和解吸性能。结果表明,经紫外光照后,吸附剂对甲基橙的吸附量为41.99 mg·g^-1,相较于可见光照后样品的吸附量提升57.56%,吸附作用增强;经可见光照后,甲基橙的脱附量为81.6%。本策略通过光照刺激改变UiO-66孔笼中SP-CH₃的构型及表面电荷性质,即对吸附活性位进行光控调节,在不同光照条件下实现对吸附质的高效吸附和有效脱附。     

Dynamic Interplay between Defective UiO-66 and Protic Solvents in Activated Processes

UiO-66, composed by Zr-oxide inorganic bricks [Zr₆(μ₃-O)₄(μ₃-OH)₄] and organic terephthalate linkers, is one of the most studied metal–organic frameworks (MOFs) due to its exceptional thermal, chemical, and mechanical stability. Thanks to its high connectivity, the material can withstand structural deformations during activation processes such as linker exchange, dehydration, and defect formation. These processes do alter the zirconium coordination number in a dynamic way, creating open metal sites for catalysis and thus are able to tune the catalytic properties. In this work, it is shown, by means of first-principle molecular-dynamics simulations at operating conditions, how protic solvents may facilitate such changes in the metal coordination. Solvent can induce structural rearrangements in the material that can lead to undercoordinated but also overcoordinated metal sites. This is demonstrated by simulating activation processes along well-chosen collective variables. Such enhanced MD simulations are able to track the intrinsic dynamics of the framework at realistic conditions.     

Unusual chain length dependent adsorption of linear and branched alkanes on UiO-66

In this work, the zero coverage adsorption properties of C₅–C₁₀ n- and iso-alkanes on the UiO-66, UiO-66-Me and UiO-66-NO₂ metal–organic frameworks are studied by gas phase pulse chromatography. Analysis of enthalpy values, entropy values, Gibbs free energies and Henry constants reveals unusual chain length dependent adsorption behaviour of linear and branched alkanes, caused by the complex structure of the zirconium metal–organic framework UiO-66. The UiO-66 structure consists of a small, tetrahedral and large, octahedral cage. It is shown that at specific carbon chain lengths (e.g. C₆–C₇ for n-alkanes), distinctive jumps in adsorption enthalpy, entropy values and Henry constants occur. This chain length dependent effect is even more pronounced for 2- and 3-methyl alkanes and double branched alkanes. This distinctive shift in adsorption behaviour occurs at a molecular size that coincides with the cavity dimensions of the smallest, tetrahedral cage. The resulting selective adsorption arises from confinement effects and is function of both the molecular shape and size.