One novel multidimensional organic-inorganic hybrid based on polyoxometalates and copper chlorine coordination polymers with 4,4’-bipyridine ligands

One novel organic-inorganic hybrid materials with 4,4’-bipy ligands and copper chlorine coordination polymers as linkers,with new topology,{[Cu^I（4,4’-bipy）]₁₀Cl₂(SiW₁₂O₄₀)₂}·6H₂O（1）（4,4’-bipy = 4,4’-bipyridine）,has been hydrothermally synthesized. The single crystal X-ray structural analysis reveals that the structure of 1 is constructed from classical Keggin anions and[Cu^I（4,4’- bipy）]cations into a novel,three-dimensional（3D） polyoxometalates（POMs）based network.From the topological view,compound 1 is a novel（3.4⁴.5².6³）（3².4⁴.5⁶.6⁹） topology.The electrochemical and photocatalysis properties of 1 have been investigated in details.     

A pure inorganic 2-D framework based on paradodecatungstate and Mn2+ ions: syntheses,structure, and properties

A pure inorganic 2-D framework based on paradodecatungstate polyanions and [Mn(H₂O)_n]²⁺ (n = 2, 3) ions, Na₁₀{[Mn(H₂O)₃]₂[H₂W₁₂O₄₂]}{[Mn(H₂O)₃]₂[Mn(H₂O)₄][H₂W₁₂O₄₂]}·56H₂O (1), has been synthesized and characterized by IR spectra, UV–vis spectra, thermogravimetric analysis (TGA), single-crystal X-ray diffraction, and magnetic measurements. Single-crystal X-ray diffraction analysis indicates that [H₂W₁₂O₄₂]^10? in 1 is a tetradentate ligand and coordinates to four [(Mn(H₂O)₃]²⁺ cations through terminal oxygens to form manganese doubly bridged 1-D chains, which are further linked through [Mn(H₂O)₄]²⁺ ions into a 2-D layer. The catalytic activities of 1 are tested in the selective oxidation of benzyl alcohol to benzaldehyde with 30% aqueous H₂O₂ as oxidant in toluene, exhibiting 90% conversion and 93% selectivity. Magnetic studies indicate that weak antiferromagnetic couplings exist between the Mn(II) ions in 1.     

Flexibility in metal-organic framework materials: Impact on sorption properties

Recent years have seen the development of a new class of porous coordination polymers known collectively as metal organic framework materials (MOFs). This review outlines recent progress in understanding how adsorption characteristics of these systems differ from rigid classical sorbents such as activated carbon and zeolites. Gas/vapor adsorption studies for characterization of the porous structures of MOF materials are reviewed and differences in adsorption characteristics based on detailed measurement of equilibrium and dynamical sorption behavior, compared with previous generations of sorbents, are highlighted. The role of framework flexibility and specific structural features, such as windows and pore cavities, within the MOF porous structures are discussed in relation to adsorption mechanisms.     

介孔结构多酸掺杂-锐钛矿纳米晶Na4W10O32/TiO2的制备及其可见光光催化性能研究

作为一种先进的氧化技术 ,光催化化学在有机污染物的降解和精细有机合成中发挥着巨大的作用 .目前 ,光催化领域中广泛使用的两类绿色光催化剂分别为二氧化钛 (锐钛矿结构 )和多金属氧酸盐 [1～ 3] .但其还存在催化活性组分在反应过程中流失和催化剂必须采用近紫外光活化等不完善之处 ,而后者是影响光催化技术实际应用的最大障碍 .因为太阳光中仅存在 2 %～ 3%的紫外光 ,太阳能的利用率极低 .因此 ,有效利用太阳光来实现光能向化学能的转换 ,进而在温和的实验条件下顺利完成无机物或有机物的光催化反应 ,是对发展未来新型光催化材料的挑战 .…     

New Anderson-Based Polyoxometalate Covalent Organic Frameworks as Electrodes for Energy Storage Boosted Through Keto-Enol Tautomerization

The unique electrochemical properties of polyoxometalates (POMs) render them ideal components for the fabrication of next-generation high-performance energy storage systems. However, their practical applications have been hindered by their high solubility in common electrolytes. This problem can be overcome by the effective hybridization of POMs with other materials. Here we present the design and synthesis of two novel polyoxometalate-covalent organic frameworks (POCOF) via one-pot solvothermal strategy between an amino-functionalized Anderson-type POM and a trialdehyde-based building unit. We show that structural and functional complexity can be enriched by adding hydroxyl groups in the 2,4,6 position to the benzene-1,3,5-tricarbaldehyde allowing to exploit for the first time in POCOFs the keto-enol tautomerization as additional feature to impart greater chemical stability to the COFs and enhanced properties leading to large specific surface area (347 m²/g) and superior electrochemical performance of the POCOF-1 electrodes, when compared with POCOF-2 electrodes that possess only imine-type linkage and with pristine POM electrodes. Specifically, POCOF-1 electrodes display remarkable specific, areal, and volumetric capacitance (125 F/g, 248 mF/cm² and 41.9 mF/cm³, respectively) at a current density of 0.5 A/g, a maximum energy density (56.2 Wh/kg), a maximum power density (3.7 kW/kg) and an outstanding cyclability (90 % capacitance retention after 5000 cycles).     

Strategies for design and synthesis of porous liquids toward carbon capture and separation

Porous liquids (PLs) represent a promising category of sorbents in carbon capture and separation capable of integrating the advantages of flowing liquid and porous solid systems. Well-defined pores were engineered into liquid sorbents via liquifying molecules with stiff interior voids, dissolving rigid porous hosts in flowing liquids, or dispersing porous frameworks in high steric hindrance solvents, producing type I, II, or III PLs, respectively. Unique features of PLs have triggered broad interest in exploring their applications in carbon capture and separation, in which diverse design strategies, synthesis approaches, and enhanced performance have been reported. In this minireview, recent progress in the design, synthesis, and structural engineering of PLs and efforts towards the optimization of their carbon capture and separation behavior will be summarized, including the comparison between PLs with varied types. Porosity engineering into liquid sorbents provides opportunities to resolve challenging issues in conventional sorption and separation systems.     

Synthesis of porous aromatic framework with Friedel–Crafts alkylation reaction for CO_2 separation

A novel porous aromatic framework, PAF-8, derived from tetraphenylsilane as basic building unit, was successfully synthesized via Friedel–Crafts alkylation reaction. This PAF material had high thermal stability as well as high surface area(785 m~2g~(-1)) calculated from the Brunauer–Emmett–Teller(BET)model. Meanwhile, PAF-8 possessed high performances in gas sorption and especially for CO_2 separation.     

Synthesis, structure and luminescent property of a new hybrid solid based on Keggin anions and silver-organonitrogen fragments

A new hybrid solid, {Ag(phen)₂}₂{[Ag(phen)]₂[PMo₁₂O₄₀]} (phen=1,10-phenanthroline) 1, constructed from one-electron-reduced mono-supported α-Keggin polyanions and silver-phenanthroline fragments via either covalent bonds or supramolecular interactions, is described. In the structure of 1, mono-supported {Ag(phen)[PMo₁₂O₄₀]}³⁻ polyanions are connected by {Ag(phen)}⁺ linking fragments to form a hybrid chain structure with engrafted phen ligands. {Ag(phen)₂}⁺ counter-cations occur in pairs trapping in strong inter-chain π-π stacking to form a three-dimensional supramolecular framework. Luminescent investigation of the compound indicates that 1 displays fascinating orange luminescent property at ambient temperature.     

Synthesis, structure and adsorption properties of nanoporous SBA-15 materials with framework and surface functionalities

Highly ordered SBA-15 nanoporous silica containing ethylene, phenylene bridges or/and amine, thiol, vinyl and phenyl surface groups were synthesized by using amphiphilic block copolymer as the structure-directing agent. The XRD data shows high degree of the order of the final structures. Obtained materials have well-developed porous structure—values of specific surface area are in the range 700–1050 m²/g and the sizes of cylindrical mesopores are in the range 6.5–9.5 nm. It was determined that size of the mesopores strongly depends even on small amounts of co-monomers co-condensing with TEOS. A new technique to introduce some amount of pendant amine groups by co-condensation of proper monomers has been proposed. Tetragonal structure was obtained when small amount of vinyl groups was introduced to the system. A new approach of determining pore size based only on the XRD measurements was compared with KJS method, confirming full usefulness of the former for calculation of the size of mesopores in SBA-15 materials. Dedicated to Professor Mietek Jaroniec on the occasion of his 60th birthday.     

Predicting adsorption isotherms of asphaltenes in porous materials

In this paper we present a molecular thermodynamics approach for the modeling of adsorption isotherms of asphaltenes adsorbed on Berea sandstone, Bedford limestone and dolomite rock, using a model for bulk asphaltenes precipitation and a quasi-two-dimensional approach for confined fluids [E. Buenrostro-González, C. Lira-Galeana, A. Gil-Villegas, J. Wu, AIChE J., 50 (2004) 2552–2570; A. Martínez, M. Castro, C. McCabe A. Gil-Villegas, J. Chem. Phys. 126 (2007) 074707, respectively], both based on the Statistical Associating Fluid Theory for Potentials of Variable Range [A. Gil-Villegas, A. Galindo, P.J. Whitehead, S.J. Mills, G. Jackson, A.N. Burgess, J. Chem. Phys. 106 (1997) 4168–4186]. The theory is applied to model adsorption isotherms from experimental data of asphaltenes extracted from a dead sample of heavy crude oil from a Mexican reservoir. The theoretical results give the right Langmuir Type II adsorption isotherms observed experimentally. The model requires the determination of ten molecular parameters related to the size of the particles and the square-well potentials used to describe the particle–surface and particle–particle interactions at the bulk and adsorbed phases. Nine parameters are taken from previous published results about the behavior of asphaltenes in bulk phases and the adsorption of several molecular fluids onto activated carbon and graphite surfaces. The remaining parameter, the energy strength of the particle–surface interaction, is adjusted to reproduce the experimental data, obtaining values that are consistent with Molecular Mechanics calculations for asphaltenes adsorbed on different surfaces and solutions. Although the agreement between theory and experiments shows some deviations at low bulk concentrations, the model reproduces adsorption data at high concentrations where other semi-empirical approaches fail.     

A 3D porous zinc MOF constructed from a flexible tripodal ligand: Synthesis, structure, and photoluminescence property

A new metal-organic framework, [Zn₅(trencba)₂(OH)₂Cl₂·4H₂O] (1) [H₃trencba=N,N,N′,N′,N′′,N′′-tris[(4-carboxylate-2-yl)methyl]-tris(2-aminoethyl)amine], constructed from a flexible tripodal ligand based on C₃ symmetric tris(2-aminoethyl)amine, has been synthesized hydrothermally and characterized by elemental analysis, IR, TG, XRD and single-crystal X-ray diffraction analysis. Compound 1 contains an unprecedented linear penta-nuclear zinc cluster fragment. Each ligand links four penta-nuclear fragments, and every fragment links eight ligands to generate a three-dimensional non-interpenetrated porous framework. The uncoordinated water molecules were observed trapped in the void pores. Compound 1 represents the first example of (6,8)-connected 3D bi-nodal framework based on a single kind of organic ligand. The photoluminescence measurements showed that complex 1 exhibits relatively stronger blue emissions at room temperature than that of the ligand.     

Synthesis and characterization of two novel pyridine-containing framework gallium ethylenediphosphonates

Two novel gallium diphosphonates, (C₅H₅N)Ga₃F(O₃PC₂H₄PO₃)₂ (I) (triclinic, P-1, a=8.2880(12) Å, b=11.7197(16) Å, c=11.7601(17) Å, α=71.589(3)°, β=70.577(3)°, γ=77.313(3)°, V=1013.7(2) Å³, Z=2, R₁=0.0352, wR₂=0.0980) and (C₅H₅NH)₂[Ga₄F₂(O₃PC₂H₄PO₃)₃] (II) (triclinic, P-1, a=8.670(4) Å, b=9.742(3) Å, c=10.406(2) Å, α=81.44(3)°, β=65.83(5)°, γ=67.16(3)°, V=739.0(4) Å³, Z=2, R₁=0.0600, wR₂=0.1495) have been synthesised by solvothermal methods in the presence of pyridine and their structures determined using single-crystal X-ray diffraction data. Both compounds I and II are composed of various Ga-centered polyhedra and ethylenediphosphonate groups that link together to form framework materials with one- and two-dimensional channel systems, respectively. The two structures are formed in the presence of structure-directing pyridine molecules that are directly bound to some of the Ga atoms in I, and are protonated as pyridinium cations in II. Compounds I has a charge-neutral framework, while compound II has an anionic framework. Both materials provide rare examples of organically structure-directed framework metal diphosphonate materials.     

Synthesis, structure and property of one porous Zn(salen)-based metal-metallosalen framework

Chiral Schiff-base ligand L was synthesized through six steps in good overall yield from readily available 2-tert-butylphenol and was used to construct one chiral porous metal-metallosalen framework,[Zn5(μ3-OH)2(ZnL)4(H2O)2]·18H2O(1,L=5′,5″-(1E,1′E)-(1R,2R)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(3′-tert-butyl-4′-hydroxybiphenyl-4-carboxylic acid),under mild reaction conditions.1 was characterized by IR,TGA,CD,UV,PL,single-crystal and powder X-ray crystallography.The structure of 1 displays a 3-fold interpenetrating 3D framework with 1D channel of 1.14 nm×0.58nm and imparts unique Zn(salen)units on the surface of the pore,in which(ZnL)2dimer acts as multi-functionlized metalloligand.1 is thermally robust with network decomposition temperature of 400oC and it also exhibits strong photoluminescence in the visible region.     

Synthesis, characterization and analytical application of a new inorganic cation exchanger—Titanium(IV) molybdophosphate

A novel polyoxometalate-cation exchanger, titanium(IV) molybdophosphate (TMP) has been synthesized under varying conditions. The material was characterized by X-ray diffraction, infrared spectroscopy, inductively coupled plasma and thermogravimetry techniques. Its stability was investigated in water, dilute acids, alkaline solutions, and high temperature up to 750 °C. Ion-exchange capacity and distribution coefficients (K_d) for twenty-nine radionuclides and metal ions have been determined. It was found that the TMP has high affinity for Cs⁺, Sr²⁺, UO₂²⁺, Ba²⁺, Pb²⁺, Tl⁺, Zn²⁺, Rb²⁺ and Zr⁴⁺ ions. The results of binary separation of metal ions showed that TMP can be potentially useful for analytical applications.     

Preparation of porous carbon directly from hydrothermal carbonization of fructose and phloroglucinol for adsorption of tetracycline

Hydrothermal carbonization of biomass is a promising method to prepare carbonaceous materials. Generally, post physical or chemical activation is necessary to increase surface area and porosity of the carbon. Herein, porous carbonaceous material (FPC) with large surface area (481.7 m²/g) and pore volume (0.73 cm³/g) was prepared directly from hydrothermal carbonization of fructose and phloroglucinol in hydroalcoholic mixture. Structure characteristics of the FPC and its adsorption capacity for a representative antibiotic tetracycline in aqueous solution were investigated. This work provides a green and efficient method to fabricate porous carbonaceous adsorbent that has great potential applications in chemical and environmental fields.     

Polyoxometalate-based eight-connected self-catenated network and fivefold interpenetrating framework

Two entangled compounds [(bpy)₆Cu^I₆Cl₃(Mo^VW₅O₁₉)] (1) and [(bpy)₇Cu^I₇Cl₂(BW₁₂O₄₀)]·H₂O (2) (bpy=4,4′-bipyridine), have been successfully synthesized under hydrothermal conditions and characterized by element analysis, IR spectroscopy, thermal gravimetric analysis, X-ray photoelectron spectroscopy, and single crystal X-ray diffraction analyses. Compound 1 represents the first eight-connected self-penetrating network constructed from cuprous chloride clusters [Cu₆Cl₃] and Lindquist-type polyoxoanions. Compound 2 exhibits an interesting fivefold interpenetrating network consisting of Keggin polyoxoanions and Cu⁺-metal-organic framework. Crystal data of the two compounds are following: 1, triclinic, , a=11.502(2) Å, b=13.069(3) Å, c=13.296(3) Å, α=90.55(3)°, β=113.74(3)°, γ=110.48(3)°, Z=1; 2, triclinic, , a=12.341(3) Å, b=13.119(3) Å, c=15.367(3) Å, α=99.12(3)°, β=90.53(3)°, γ=104.49(3)°, Z=1.     

Facile synthesis of palladium nanoparticles supported on urea-based porous organic polymers and its catalytic properties in Suzuki-Miyaura coupling

By using urea linked porous organic polymers as template, a new nano palladium catalyst with low Pd loading can be easily prepared (1.0 wt% Pd only). Although such less amount of Pd was contained in this new catalyst, it is still an effective catalyst for the Suzuki-Miyaura coupling of aryl iodines and aryl boric acids, affording biphenyl products in excellent yields with outstandingly enhanced turnover numbers (up to 10,536) under green solvent (water).     

Ordered porous metal oxide semiconductors for gas sensing

This review gives a comprehensive summary about the porous metal oxides with focus on the synthesis methods, structure related properties, as well as the modification strategies for gas sensing improved performances.     

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.     

Facile fabrication of porous pure and Ag nanoparticle-doped poly(4-vinylpyridine) films at the liquid-liquid interfaces

We reported an interfacial self-assembly of regularly layered porous poly(4-vinylpyridine)(P4VP) films at the interfaces of water-chloroform or -dichloroethane.The porous diameters were in the range from hundred nanometers to several micrometers.It was revealed that formation of such kind of porous materials was solvent dependent.Moreover,cyclic Ag nanoparticles could be grown in the porous P4VP films to form Ag-P4VP nanohybrids under radiation.