Mixed Linker Metal Organic Framework as an Efficient and Reusable Catalyst for Suzuki Miyaura Coupling Reaction

Series of metal organic frameworks from nitrogen based ligand were synthesized as efficient and reusable catalyst via mixed linker methods. The thermogravimetric study of the mixed linker metal organic framework (MIXMOF) reveals that the complexes are potential thermally stable materials. The palladium supported catalysts exhibits high catalytic activity toward the Suzuki-Miyaura cross coupling reaction and can be reused several times without any visible loss of activity even after five consecutive times.     

Synthesis,structure and characterization of two new metal–organic coordination polymers based on the ligand 5‐iodobenzene‐1,3‐dicarboxylate

Two new coordination polymers (CPs) formed from 5‐iodobenzene‐1,3‐dicarboxylic acid (H₂iip) in the presence of the flexible 1,4‐bis(1H‐imidazol‐1‐yl)butane (bimb) auxiliary ligand, namely poly[[μ₂‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ²N³:N^3′](μ₃‐5‐iodobenzene‐1,3‐dicarboxylato‐κ⁴O¹,O^1′:O³:O^3′)cobalt(II)], [Co(C₈H₃IO₄)(C₁₀H₁₄N₄)]_n or [Co(iip)(bimb)]_n, (1), and poly[[[μ₂‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ²N³:N^3′](μ₂‐5‐iodobenzene‐1,3‐dicarboxylato‐κ²O¹:O³)zinc(II)] trihydrate], {[Zn(C₈H₃IO₄)(C₁₀H₁₄N₄)]·3H₂O}_n or {[Zn(iip)(bimb)]·3H₂O}_n, (2), were synthesized and characterized by FT–IR spectroscopy, thermogravimetric analysis (TGA), solid‐state UV–Vis spectroscopy, single‐crystal X‐ray diffraction analysis and powder X‐ray diffraction analysis (PXRD). The iip²⁻ ligand in (1) adopts the (κ¹,κ¹‐μ₂)(κ¹, κ¹‐μ₁)‐μ₃ coordination mode, linking adjacent secondary building units into a ladder‐like chain. These chains are further connected by the flexible bimb ligand in a trans–trans–trans conformation. As a result, a twofold three‐dimensional interpenetrating α‐Po network is formed. Complex (2) exhibits a two‐dimensional (4,4) topological network architecture in which the iip²⁻ ligand shows the (κ¹)(κ¹)‐μ₂ coordination mode. The solid‐state UV–Vis spectra of (1) and (2) were investigated, together with the fluorescence properties of (2) in the solid state.     

Metal-ion Interactions with Sugars: Crystal Structure of Bis(4-dehydro-L-arabinose) Calcium Methanol Bishydrate

The crystal structure of the metal-organic frame Ca(C5H9O5)2·CH3OH·2H2O(1) has been synthesized and characterized.Complex 1 belongs to a tetragonal P43212 space group.In complex 1,the sugar moiety shows a beta-L configuration of pyranose form.The calcium(Ⅱ) is eight-coordinated,binding to four such sugar moieties,via O(1),O(2) of two molecules and O(3),O(4) of the other two,with the 4-hydroxy group being deprotonated.The water and methanol molecules are not coordinated to the calcium ion.     

铁脂质体/水分配系数测定及影响因素考察

基于PAF-301分子模型通过Li 掺杂或B取代等模式设计了几种新型多孔芳香骨架(PAFs)材料, 采用量子力学和分子力学方法对新材料的储氢性能进行研究. 由量子力学计算得到了不同分子片段与H₂之间的结合能, 并结合DDEC方法计算了各分子片段的原子电荷分布. 利用巨正则蒙特卡洛(GCMC)模拟方法计算了77和298 K下H₂在不同PAFs材料中的吸附平衡性质. 结果表明, H₂直接与苯环的结合能较低, 但掺杂Li 原子能够提高H₂与六元环的结合能, 同时Li 原子体现出较高的正电性质, B原子取代苯环中的两个C原子后, 使得原有C原子电负性增强; 77 K下PAF-301Li 具有最高的储氢性能, 而PAF-C₄B₂H₄-Li₂-Si 和PAF-C₄B₂H₄-Li₂-Ge体现出较好的常温储氢性能, 各种材料的常温储氢性能远低于其低温储氢性能. 通过77 K下H₂在PAFs材料中的等位能面分布和吸附平衡质心密度分布对H₂在PAFs 材料中的优先吸附位置进行分析, 发现在PAF-301 和PAF-301Li 骨架中, 由于中心能量较低的等位能区域范围较宽, H₂在其中存在四个明显的吸附高密度分布区域, 而其它三种PAFs晶胞中心能量较低的等位能区域范围较窄, 使得H₂在其中只存在两个明显的吸附高密度分布区域.     

以T型三羧酸配体构筑的具有2D→3D穿插结构的金属有机框架的合成、结构及性质

采用溶剂热合成法,利用T型三羧酸配体3,4',5-联苯三羧酸(H₃BPT=biphenyl-3,4',5-tricarboxylicacid)制备并表征了2个2D→3D穿插结构的金属有机框架结构,{[Ni₃(BPT)₂(bpe)₂(H₂O)₆]·2DMF·7H₂O}_n(1)和{[Ni₃(BPT)₂(bpea)₂(H₂O)₆]·2DMF·5H₂O}_n(2)(bpe=1,2-bis(4-pyridyl)ethylene,bpea=1,2-bis(4-pyridyl)ethane,DMF=N,N-dimethylformamide)。在这2个化合物中,BPT配体和含氮配体bpe或bpea共同连接相邻的Ni(Ⅱ)中心,形成(3,4)-连接的(63)(65.8)二维双层结构。相邻双层结构间相互穿插,形成具有聚轮烷结构的2D→3D互锁结构。气体吸附性质表明,化合物1对CO₂和N₂具有一定的吸附能力。     

Impact of the flexibility of pillar linkers on the structure and CO_2 adsorption property of ‘‘pillar-layered' MOFs

A new metal–organic framework {[Zn_2(bpta)(bpy-ee)(H_2O)_2]·x solve}_n(1)(H_4bpta = biphenyl-2,20,6,60-tetracarboxylic acid and bpy-ee = 1,2-bis(4-pyridyl)ethylene) has been obtained under hydrothermal condition, and structurally characterized by single-crystal X-ray diffraction. Complex 1 reveals a threedimensional(3D) ‘‘pillar-layered' framework with non-flexible linker, in which some different structure characters can be found compared to that of some related other ‘‘pillar-layered' MOFs based on flexible pillar linkers. It demonstrates the impact of the flexibility of pillar linker on the final structure in this system. In addition, the selective CO_2 adsorption performance of 1 was also investigated.     

Solution‐Mediated Transformation of a 1D [Zn(Im)(HIm)2(OAc)] Precursor to Several Different 3D Zn(Im)2 Frameworks

1D compound [Zn(Im)(HIm )₂(OAc )] was used as a single precursor of metal and imidazole to prepare several 3‐dimensional (3D ) Zn(Im)₂ frameworks by solution‐mediated transformation. Specifically, three known topologies, zni, coi and crb (BCT ) were obtained using a solution‐mediated transformation with CH₃OH , DMF and DMA as solvent, respectively. Structural studies by ¹³C MAS NMR spectroscopy and TG imply that in the transformation process from 1D compound to coi‐[Zn(Im)₂]•(DMF )_x and crb‐[Zn(Im)₂]•(DMA )_x (ZIF ‐1), DMF and DMA solvent molecules acted as structure‐directing agent and, therefore, were occluded inside the framework, respectively. In contrast, in the formation of zni‐[Zn(Im)₂], no solvent molecules were present in the frameworks; therefore the transformation from 1D compound to zni was induced by temperature. Thus, solution‐mediated transformation of a single precursor (1D compound) approach was established for the synthesis of ZIFs .     

手性金属-有机骨架[Cu_3(HL)_2(L)_2(bpy)_3]·4H_2O用于高效液相色谱拆分手性化合物

手性金属-有机骨架材料(MOFs)作为一种新型多孔材料,由于具有比表面积大、结构多样、孔尺寸可调和化学稳定性良好等特点,而备受色谱分离领域的关注。该文以(1R,2R)-1,2-环己烷二甲酸(H2L)和4,4'-联吡啶(bpy)为配体与铜离子反应,通过溶剂热法合成了一种具有二维手性网状结构的手性MOF[Cu_3(HL)_2(L)_2(bpy)_3]·4H_2O。将该手性MOF作为手性固定相制备了高效液相色谱柱。为了考察MOF[Cu_3(HL)_2(L)_2(bpy)_3]·4H_2O的手性识别能力,在正相色谱(流动相:正己烷-异丙醇)条件下,对一系列外消旋化合物在手性MOF柱上进行了拆分。该手性MOF柱对醇类、酮类、酸类、环氧化合物和醚类等10种手性化合物表现出较好的拆分效果。对该手性MOF柱的重现性、稳定性作了评价,考察了进样量对分离效果的影响,结果表明该手性MOF柱具有较好的重现性和稳定性。     

A Fluorescent Zirconium‐Based Metal‐Organic Framework for Selective Detection of Nitro Explosives and Metal Ions

In this work, a new porous Zr‐based metal‐organic framework (MOF ) with a large Brunner‐Emmet‐Teller (BET ) surface area was prepared by the solvothermal method using 4,4’‐(naphthalene‐1,4‐diyl)dibenzoic acid (NDDA ) as the organic ligand, and the luminescent detection performance was studied systematically. The experiments combing with computations indicate that the as‐synthesized material can sensitively and selectively detect nitro explosives and metal ions, especially for 2,4,6‐trinitrophenol (TNP ) and Fe³⁺, due to the possible electron transfer from inorganic moieties to organic moieties with naphthalene part. Interestingly, owing to its high porosity and large surface area, this Zr‐MOF showed quick luminescent response time (in 1 min) for TNP and Fe³⁺. The results obtained may provide useful information for the design of MOFs with the large permanent porosity in sensing applications for large molecules in the future.     

A three‐dimensional cadmium coordination polymer based on 1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene and benzene‐1,3,5‐tricarboxylic acid

The Cd^II three‐dimensional coordination poly[[[μ₄‐1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene]bis(μ₃‐5‐carboxybenzene‐1,3‐dicarboxylato)dicadmium(II)] dihydrate], {[Cd₂(C₉H₄O₆)₂(C₈H₁₀N₆)]·2H₂O}_n , (I), has been synthesized by the hydrothermal reaction of Cd(NO₃)₂·4H₂O, benzene‐1,3,5‐tricarboxylic acid (1,3,5‐H₃BTC) and 1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene (1,4‐btbe). The IR spectrum suggests the presence of protonated carboxylic acid, deprotonated carboxylate and triazolyl groups. The purity of the bulk sample was confirmed by elemental analysis and X‐ray powder diffraction. Single‐crystal X‐ray diffraction analysis reveals that the Cd^II ions adopt a five‐coordinated distorted trigonal–bipyramidal geometry, coordinated by three O atoms from three different 1,3,5‐HBTC²⁻ ligands and two N atoms from two different 1,4‐btbe ligands; the latter are situated on centres of inversion. The Cd^II centres are bridged by 1,3,5‐HBTC²⁻ and 1,4‐btbe ligands into an overall three‐dimensional framework. When the Cd^II centres and the tetradentate 1,4‐btbe ligands are regarded as nodes, the three‐dimensional topology can be simplified as a binodal 4,6‐connected network. Thermogravimetric analysis confirms the presence of lattice water in (I). Photoluminescence studies imply that the emission of (I) may be ascribed to intraligand fluorescence.