Showing papers in "Crystal Growth & Design in 2017"
TL;DR: In this article, two luminescent Cd(II)-metal-organic frameworks (MOFs) have been synthesized using Cd2+ ion and L ligand in the presence of auxiliary ligands and characterized by infrared spectroscopy, elemental analysis, powder X-ray diffraction, and thermogravimetry measurement.
Abstract: Two new luminescent Cd(II)-metal–organic frameworks (MOFs), {[Cd(L)(BPDC)]·2H2O}n (1) and {[Cd(L)(SDBA)(H2O)]·0.5H2O}n (2) [L = 4,4′-(2,5-bis(methylthio)-1,4-phenylene)dipyridine, H2BPDC = 4,4′-biphenyldicarboxylic acid, H2SDBA = 4,4′-sulfonyldibenzoic acid], have been solvothermally synthesized using Cd2+ ion and L ligand in the presence of auxiliary ligands and characterized by infrared spectroscopy, elemental analysis, powder X-ray diffraction, and thermogravimetry measurement. Topological analyses reveal that MOF 1 is a 6-connected 3-fold interpenetrating pcu network, and MOF 2 is a new 4-connected 2-fold interpenetrating network. Fluorescence titration, cyclic and anti-interference experiments demonstrate that MOFs 1 and 2 both are excellent probes for Fe3+, CrO42–, and Cr2O72–. The mechanisms of quenching are also deeply studied.
267 citations
TL;DR: In this paper, the discovery of superior mid-IR NLO metal chalcogenides is still a big challenge mainly due to the difficulty of achieving a good balance between the NLO effect and laser damage threshold (LDT).
Abstract: Mid-infrared (IR) nonlinear optical (NLO) materials with high performance are vital to expanding the laser wavelengths into the mid-IR region and have important technological applications in many civil and military fields. For the last two decades metal chalcogenides have attracted great attention since many of them possess a large NLO effect, wide transparent range, moderate birefringence, and high resistance to laser damage. However, the discovery of superior mid-IR NLO metal chalcogenides is still a big challenge mainly due to the difficulty of achieving a good balance between the NLO effect and laser damage threshold (LDT). In this review, metal chalcogenides are catalogued according to the different types of microscopic building blocks. These groups include triangle planar units, tetrahedral metal-centered units, polyhedra with second-order John-Teller cations, and polyhedra with stereochemically active lone electron pairs cations, rare-earth cations, and/or halogen anions. The determinations of thes...
242 citations
TL;DR: In this article, three luminescent MOFs (1,2,2-tetrakis(4-(pyridin-4-yl)phenyl)ethane (TPPE) with the π-electron-rich tetraphenylethylene (TPE) and aggregation induced emission feature is selected as functional ligand to construct the fluorescent metal-organic frameworks.
Abstract: From the perspective of the chromophore, 1,1,2,2-tetrakis(4-(pyridin-4-yl)phenyl)ethane (TPPE) with the π-electron-rich tetraphenylethylene (TPE) and aggregation induced emission feature is selected as functional ligand to construct the fluorescent metal–organic frameworks. Three luminescent MOFs (1–3) have been successfully synthesized. Through combining 4,4′,4″-nitrilotrisbenzoic acid (H3TNB) with electron-donor triphenylamine (TPA), the highly porous pillared-layer compound 1 [Zn3(TPPE)1/2(TNB)2](4DMA·7H2O) was synthesized; interestingly, this MOF sensor film realizes the fast detection for nitrobenzene compounds with a response time of less than 3 min as well as good recyclability. Compound 2 [Zn7(TPPE)2(SO42–)7](DMF·H2O) exhibits the clear “turn-off” quenching responses for Cr2O72– in aqueous phase with high selectivity and sensitivity. Meanwhile, the fluorescent properties of compound 3 [Zn2(TPPE)3/2(NO3–)(OH–)(H2O)](DMF·2H2O) were also investigated. Thus, these MOF materials could serve as the prom...
235 citations
TL;DR: In this paper, a critical perspective on the construction of bimetallic porous metal-organic frameworks (MOFs) is presented, involving one-step synthesis and post-synthetic modification, and their applications in gas storage and separation.
Abstract: Emerging as a new family of hybrid crystalline materials, bimetallic porous metal–organic frameworks (MOFs) have received great attention in gas storage and separation. We present a critical perspective on the construction of bimetallic MOFs, involving one-step synthesis and postsynthetic modification, and their applications in gas storage and separation. In particular, several examples of bimetallic MOFs have been provided to better understand of why such MOFs are so unique for these applications. We hope that the present perspective will inspire chemists working in this area to rationally design/develop new bimetallic MOFs for advanced applications.
230 citations
TL;DR: In this paper, the authors describe a novel and simple method to prepare one of the most widely studied metal-organic frameworks (MOFs) materials, i.e., MIL-100(Fe), which significantly improves the sustainability of the conventional process in several aspects.
Abstract: The real industrial establishment of metal–organic frameworks (MOFs) requires significant advances in economic and chemical sustainability. This work describes a novel and simple method to prepare one of the most widely studied MOF materials, i.e., MIL-100(Fe), which significantly improves the sustainability of the conventional process in several aspects. This MOF material is prepared (i) at room temperature (instead of 150 °C used in the conventional method), (ii) after a few hours (instead of 6 days), (iii) in the absence of any inorganic corrosive acid (significant amounts of HF and HNO3 are used in the conventional method), and (iv) it is washed at room temperature (unlike the washing at 80 °C for 3 h). Interestingly, the only difference in the preparation method of MIL-100(Fe) compared with that of semiamorphous Fe-BTC (MOF material commercialized as Basolite F300 having the same metal and linker, and which can be also prepared under similar sustainable conditions) is to start from Fe(II) or Fe(III) ...
226 citations
TL;DR: In this article, a computational algorithm and code to generate MOFs based on edge-transitive topological nets for subsequent evaluation via molecular simulation is described in detail, which has been previously used by us to construct and evaluate 13 512 MOFs of 41 different topologies for cryo-adsorbed hydrogen storage.
Abstract: Metal–organic frameworks (MOFs) are promising materials for a range of energy and environmental applications. Here we describe in detail a computational algorithm and code to generate MOFs based on edge-transitive topological nets for subsequent evaluation via molecular simulation. This algorithm has been previously used by us to construct and evaluate 13 512 MOFs of 41 different topologies for cryo-adsorbed hydrogen storage. Grand canonical Monte Carlo simulations are used here to evaluate the 13 512 structures for the storage of gaseous fuels such as hydrogen and methane and nondistillative separation of xenon/krypton mixtures at various operating conditions. MOF performance for both gaseous fuel storage and xenon/krypton separation is influenced by topology. Simulation data suggest that gaseous fuel storage performance is topology-dependent due to MOF properties such as void fraction and surface area combining differently in different topologies, whereas xenon/krypton separation performance is topology...
152 citations
TL;DR: In this paper, the formation process for the regular decahedron BiVO4 crystals prepared by a convenient hydrothermal method was investigated, and the phase was transformed from tetragonal zircon type to monoclinic sheelite type.
Abstract: Precise control of the morphology and crystalline structure of semiconductor-based photocatalyst is crucial for improving the efficiency of solar energy conversion system. In this work, taking BiVO4 semiconductor photocatalyst as an example, we investigated the formation process for the regular decahedron BiVO4 crystals prepared by a convenient hydrothermal method and found that the synthesis is undergoing a dissolution–recrystallization process, concomitantly, the phase was transformed from tetragonal zircon type to monoclinic sheelite-type. By controlling the kinetics of crystal growth for BiVO4 through regulating acidity of the reaction solution, we rationally tune the morphology of monoclinic BiVO4 from regular decahedron crystals to short rod-like particles, particularly precisely modulate the proportion of {010}/{011} facets for the decahedron BiVO4. By tuning the crystalline phase and morphologies of BiVO4 crystal, we found that the photocatalytic water oxidation activity for the well-defined BiVO4...
147 citations
TL;DR: In this paper, the growth rate of CsPbBr3 was tailored by diluting the antisolvent MeOH solution using DMSO to reduce the MeOH vapor pres...
Abstract: As a member of the lead-halide perovskite family, inorganic perovskite CsPbBr3 exhibits excellent optical and electrical properties with higher stability to the environment. However, former efforts to obtain large-size CsPbBr3 single crystals with satisfactory quality using low temperature solution methods reached limited results. In this work, we have studied the growth of CsPbBr3 crystals using the antisolvent vapor-assisted crystallization (AVC) method. By adjusting the mole ratio of PbBr2 and CsBr, the phase diagram of the final products is acquired. Five regions are identified, including the Cs4PbBr6 single phase region, Cs4PbBr6 and CsPbBr3 two phases region, CsPbBr3 single phase region, CsPbBr3 and PbBr2·2[(CH3)2SO] metastable two phases region, and CsPbBr3 and PbBr2·2[(CH3)2SO] two phases region. Three methods are adopted to improve the size and crystalline quality of CsPbBr3. The growth rate is effectively tailored by diluting the antisolvent MeOH solution using DMSO to reduce the MeOH vapor pres...
137 citations
TL;DR: In this paper, four new isostructural two-dimensional lanthanide(III)-metal organic frameworks (MOFs), namely, [Ln(L)(HCOO)(H2O)]n (Ln = Eu 1, Gd 2, Ho 3, and Tb 4, H2L = 5-((2′-cyano-[1,1′-biphenyl]-4-yl)methoxy)isophthalic acid), with a uninodal {44.62}-sql topology have been
Abstract: Four new isostructural two-dimensional lanthanide(III)–metal organic frameworks (MOFs), namely, [Ln(L)(HCOO)(H2O)]n (Ln = Eu 1, Gd 2, Ho 3, and Tb 4, H2L = 5-((2′-cyano-[1,1′-biphenyl]-4-yl)methoxy)isophthalic acid), with a uninodal {44.62}-sql topology have been successfully isolated. Compounds 1 and 4 exhibit excellent applications as luminescent sensors for sensing benzaldehyde in methanol and Cr3+, CrO42–, and Cr2O72– in water with high sensitivity and selectivity based on luminescence quenching effects. Interestingly, 1 and 4 display excellent recyclable behaviors and can be recycled at least five times for sensing benzaldehyde, Cr(III) and Cr(VI) ions. These two compounds are the first multifunctional Ln–MOFs sensors for detecting benzaldehyde, Cr(III) and Cr(VI) ions, simultaneously. Therefore, these two materials may be excellent multifunctional recyclable luminescent sensors.
135 citations
TL;DR: In this article, an ultrathin MoS2 nanosheets with defect-rich structure were prepared and used as catalysts for the reduction of p-nitropheonol.
Abstract: In this work, ultrathin MoS2 nanosheets (MoS2 NSs) with defect-rich structure were prepared and used as catalysts for the reduction of p-nitropheonol. Also, thanks to the defect sites, noble metal (Au, Ag, Pd, Pt) nanoparticles (NPs) can be successfully deposited on the MoS2 NSs via a facile and efficient one-step photochemical reduction process without the assistance of a stabilizer. The morphology and crystal structure of as-synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N2 physisorption mearurements. Catalytic results demonstrate that as-prepared MoS2 NSs and noble metal modified MoS2 NSs (NM/MoS2 NSs) effectively catalyze the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) with NaBH4. The Pd/MoS2 NSs shows the best catalytic performance, exhibiting an apparent rate constant (κapp) of 0.386 min–1 even with moderate chemical stability. Interestingly, the...
129 citations
TL;DR: In this paper, the synthesis, characterization, and crystal structure of a neutral two-dimensional adenine-based luminescent coordination polymer (LCP) with Zn(II) metal nodes were reported.
Abstract: The present work reports the synthesis, characterization, and crystal structure of a neutral two-dimensional adenine-based luminescent coordination polymer (LCP) with Zn(II) metal nodes. The photoluminescence property of the d10 LCP [Zn(μ2-1H-ade)(μ2-SO4)] (1) has been exploited to use 1 as a dual detection probe for the selective sensing of Hg2+ and 2,4,6-trinitrophenol (TNP) in the aqueous phase from among a variety of cations and a pool of aromatic nitro compounds, respectively. Competitive fluorometric experiments involving a series of cation combinations or mixture of nitro compounds established 1 as an efficient and selective sensor for Hg2+ and TNP in aqueous solutions. The limits of detection for sensing of Hg2+ and TNP in aqueous solutions using LCP 1 are 70 and 0.4 nM, respectively. For in-field sensing applications, 1-coated test paper strips have been developed. They show luminescence upon exposure to UV radiation, and the luminescence intensity is quenched upon addition to aqueous solutions o...
TL;DR: In this article, the authors report on the applicability of an easy general synthesis procedure for the formation of Ce(IV)-MOFs which contain hexanuclear clusters and extend the series of Ce-IV-based MOFs to reo and spn topologies.
Abstract: We report on the applicability of an easy general synthesis procedure for the formation of Ce(IV)-MOFs which contain hexanuclear clusters. Thus, the series of Ce(IV)-based MOFs isoreticular to their Zr analogues has been extended to reo and spn topologies. Four new MOFs denoted as Ce-UiO-66-BPyDC [Ce6(μ3-O)4(μ3-OH)4(BPyDC)6] (BPyDC2– = 2,2′-bipyridine-5,5′-dicarboxylate), Ce-DUT-67-PZDC [Ce6(μ3-O)4(μ3-OH)4(PZDC)4(OH)4(H2O)4] (PZDC2– = 3,5-pyrazoledicarboxylate), Ce-DUT-67-TDC [Ce6(μ3-O)4(μ3-OH)4(TDC)4(OH)4(H2O)4] (TDC2– = 2,5-thiophenedicarboxylate), and Ce-MOF-808 [Ce6(μ3-O)4(μ3-OH)4(BTC)2(OH)6(H2O)6] (BTC3– = benzene-1,3,5-tricarboxylate) were obtained under mild reaction conditions (100 °C) and after short reaction times (15 min) using a modulated synthesis approach. The MOFs differ in their connectivity of the [Ce6O4(OH)4(−CO2)x] (x = 12, 8, 6) cluster, the geometry of the organic linker molecules (linear and bent dicarboxylic acids, tricarboxylic acid), and the resulting topology (fcu, reo, spn). The...
TL;DR: In this paper, the authors focus on the solid state structural transformations in discrete molecules and present some interesting examples from the literature on SCSC transformation at the discrete molecular level using various external stimuli, such as light, heat, uptake or exchange of solvent, mechanochemical force, etc.
Abstract: The present review focuses on the solid state structural transformations in discrete molecules. Since the molecules in the crystal lattice are closely packed, any transformation in the solid state is difficult due to restricted movement of the molecules. These transformations can be triggered by external stimuli, such as light, heat, uptake or exchange of solvent, mechanochemical force, etc. which may be observed by a change in their physical properties like color, magnetism, porosity, and optical. Single-crystal-to-single-crystal (SCSC) transformations in metal–organic frameworks and coordination polymers are well documented; however, reports on SCSC transformations at the discrete molecular level still remain scarce. In this review, we have compiled some interesting examples from the literature on SCSC transformation at the discrete molecular level using various external stimuli.
TL;DR: The micron and nanometer-sized γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs) were successfully synthesized using the microwave technique for the first time for rapid and facile synthesis as discussed by the authors.
Abstract: The micron and nanometer-sized γ-cyclodextrin metal–organic frameworks (γ-CD-MOFs) were successfully synthesized using the microwave technique for the first time for rapid and facile synthesis. Polyethylene glycol 20000 (PEG 20000) was used as surfactant to control the size and morphology of γ-CD-MOFs. The as-synthesized γ-CD-MOFs were characterized using various techniques, including X-ray powder diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and N2 adsorption. The increment in the reaction time and MeOH ratio dramatically damaged the crystalline integrity of γ-CD-MOFs. Fenbufen was selected as a model drug to evaluate the loading characteristics of γ-CD-MOF crystals. As a result, the nanometer sized γ-CD-MOFs (100–300 nm) showed rapid and higher adsorption (196 mg g–1) of Fenbufen in EtOH when compared with the micron crystals. The adsorption parameters fitted well to a pseudo-second-order kinetic model and chemisorption of Fenbufen was further supported by mol...
TL;DR: In this paper, the authors present a review of the challenges in the context of MOF synthesis and membrane fabrication by the choice of appropriate polymer/MOF combinations, utilization of the MOF functional sites, modification of the surface chemistry or pore texture and s...
Abstract: Metal–organic frameworks (MOFs), as porous fillers possessing molecular sieving properties, have been combined with polymers to give mixed-matrix membranes (MMMs) with enhanced separation performance. This field of research has produced a large number of different membranes, and many MOF/polymer combinations have been tested and reported to show potential application to industrial gas separation. Although MOFs have been proposed as novel additives with high porosity and tunable pore size, which were supposed to outperform other porous fillers, due to restrictions in separation performance of the filler and challenges concerning the compatibility of polymer and MOF, only a small fraction of these works report both improved permeability and selectivity. In this review these challenges are set into the context of MOF synthesis and membrane fabrication by the choice of appropriate polymer/MOF combinations, utilization of the MOF functional sites, modification of the MOF surface chemistry or pore texture and s...
TL;DR: In this paper, single crystals of the birefringent material Ba2Ca(B3O6)2 (BCBO) with dimensions up to 40 × 28 × 10 mm3 were successfully grown by top-seeded solution growth (TSSG) method from B2O3-NaF flux.
Abstract: Single crystals of the birefringent material Ba2Ca(B3O6)2 (BCBO) with dimensions up to 40 × 28 × 10 mm3 were successfully grown by top-seeded solution growth (TSSG) method from B2O3–NaF flux. It exhibits high transmittance in the range of 190–3000 nm with UV cutoff of 178 nm, which is much shorter than that (189 nm) of the commercial UV birefringent crystal, the high-temperature phase of BaB2O4 (α-BBO). Meanwhile, BCBO crystal has large birefringence (Δn = no – ne = 0.2524–0.0862) in the wavelength range from 178 to 3000 nm and without phase transition from room temperature to the melting point. A prototype of Glan–Taylor polarizer made from BCBO crystal showed an optical extinction ratio of 104:1, which is comparable to those of commercial birefringence crystals. The experimental results demonstrate that the BCBO crystal can be a new promising birefringent crystal for UV, especially the sub-200 nm deep-UV range.
TL;DR: In this paper, a co-crystal of tramadol hydrochloride and celecoxib was identified, which is formed by an intrinsic 1:1 molecular ratio of rac-tramadol and HCl and exhibited favorable physicochemical and dissolution profiles.
Abstract: We have identified a co-crystal of tramadol hydrochloride–celecoxib (ctc; E-58425/MR308), a novel active pharmaceutical ingredient (API)–API co-crystal formed by an intrinsic 1:1 molecular ratio of rac-tramadol·HCl and celecoxib, which displays favorable physicochemical and dissolution profiles. Adequate treatment of pain represents an unmet medical need that is often addressed via combination therapy. API–API co-crystals represent a new approach with potential to improve physicochemical properties, bioavailability, stability, or formulation capacity, which may translate into optimized pharmacokinetic profiles and clinical benefits compared with individual APIs or their combination. ctc showed a well-defined differential scanning calorimetry profile, and its single-crystal X-ray diffraction structure demonstrated a supramolecular 3D network in which the two active enantiomers of tramadol and celecoxib are linked via hydrogen bonding and chloride ions. Oversaturation studies indicated that the saturation e...
TL;DR: In this paper, the planar (C3N3O3)3-anion, the main fundamental building block in inorganic metal cyanurates, is highlighted as an outstanding candidate of building blocks for nonlinear optical materials.
Abstract: Molecular construction using good optically active microscopic units is vital to efficiently explore good nonlinear optical (NLO) materials, a type of important optoelectronic functional materials In this work, we highlight the planar (C3N3O3)3– anion, the main fundamental building block in inorganic metal cyanurates, as an outstanding candidate of building blocks for NLO materials Several noncentrosymmetric metal cyanurates containing the (C3N3O3)3– groups are studied by the first-principles calculations for the first time It is shown that these materials possess wide band gaps (Eg > 55 eV), high SHG coefficients (d22 > 2 × BBO), and large birefringence values (Δn > 01) and thus have good potentials in the ultraviolet NLO applications Moreover, the key role of the (C3N3O3)3– groups to the good NLO performance in the cyanurates is elucidated On the basis of the first-principles analysis, some possible searching directions of good NLO materials containing (C3N3O3)3– groups are proposed
TL;DR: In this article, the pore size, temperature, and pressure effect on gas diffusion as well as nonequilibrium gas separation in metal-organic frameworks (MOFs) are discussed.
Abstract: Metal–organic frameworks (MOFs) are a class of crystalline inorganic–organic hybrid materials that have demonstrated huge potential in gas separation due to their ultrahigh porosity, boundless chemical tunability, as well as surface functionality. Most gas separations realized in MOFs are under an equilibrium state and are dependent on the difference in thermodynamic affinities of gases to MOFs, whereas nonequilibrium separation such as kinetic and molecular sieving separation attracting growing attention in the past decade is achieved based on the difference in the size and diffusivity of gas molecules. In this perspective, we first discuss the pore size, temperature, and pressure effect on gas diffusion as well as nonequilibrium gas separation in MOFs. Second, we introduce current techniques reported to measure intracrystalline gas diffusivity. Third, we review recent progress in MOF-based nonequilibrium N2/O2 separation, CO2 capture, and hydrocarbon separation. In addition, we describe the hydrogen iso...
TL;DR: One tetracarboxylate functionalized benzene-cored tetraphenylethene derivative was designed as a linker for construction of aggregation-induced emission (AIE) active metal-organic frameworks (MOFs) which exhibit the distinct AIE behavior as discussed by the authors.
Abstract: One tetracarboxylate functionalized benzene-cored tetraphenylethene derivative was designed as a linker for construction of aggregation-induced emission (AIE) active metal–organic frameworks (MOFs), which exhibit the distinct AIE behavior. Two two-dimensional MOFs materials, MOF-1 and MOF-2, have been successfully synthesized by using the organic linker precursor. Photophysical studies reveal that both MOFs exhibit remarkable fluorescent properties with the absolute quantum yield as high as 43%. The high PL efficiency, good water stability, as well as the electron-donating nature of prepared MOF materials, allow us to explore their potentials in sensing applications for electron-deficient nitro explosives in aqueous media. Especially, water-stable MOF-2 exhibits superior sensitivity and selectivity toward 2,4,6-trinitrophenol (TNP) over other selected nitro analytes, including nitromethane, 2,3-dimethyl-dinitrobutane, nitrobenzene, 2,4,6-trinitrotoluene, 2,6-dinitrotoluene, 2,4-dinitrotoluene, 1,3-dinitro...
TL;DR: In this paper, the structure and morphology of as-prepared CuO particles have been fully characterized by the usage of XRD, XPS, SEM, and TEM, and the results show that CuO-400 with spherical shape displays unprecedented high response (maximum value, 102) for triethylamine (TEA) at 100 ppm with a low detection limit of 5 ppm, a lower working temperature (230 °C), excellent reproducibility, and long-term stability.
Abstract: Because porous metal oxides with controllable morphologies have been attracting much attention for their potential applications in the fields of adsorption/separation, sensing, energy storage, and conversion, it is highly desirable to prepare new morphology of metal oxides and investigate their performance. In this work, CuO particles with different shapes such as octahedron, sponge-like octahedron, and sphere have been synthesized through thermal decomposition of crystalline Cu(II)–organic frameworks (HKUST-1). The structure and morphology of as-prepared CuO particles have been fully characterized by the usage of XRD, XPS, SEM, and TEM. The gas-sensing behaviors of these CuO samples have been investigated and our results show that CuO-400 with spherical shape displays unprecedented high response (maximum value, 102) for triethylamine (TEA) at 100 ppm with a low detection limit of 5 ppm, a lower working temperature (230 °C), excellent reproducibility, and long-term stability. The highly sensing behavior o...
TL;DR: In this paper, the in situ growth of Bi-based metalorganic framework (MOF) (CAU-17) on BiOBr 2D material was prepared for the first time by using a facile solvothermal transformation approach.
Abstract: The in situ growth of Bi-based metal–organic framework (MOF) (CAU-17) on BiOBr 2D material was prepared for the first time by using a facile solvothermal transformation approach. The BiOBr was applied both as template to support the growth of MOF and as Bi3+ source of MOF. The BiOBr/CAU-17-2h composite exhibited enhanced photocatalytic activity for degradation of Rhodamine B (RhB), methylene blue (MB), and methyl orange (MO) under visible light irradiation, suggesting a good synergy between BiOBr and CAU-17 MOF.
TL;DR: In this article, the authors used powder X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, dynamic vapor sorption, and Fourier transform infrared spectroscopy to obtain cocrystals of Bai with isoniazide (Inia), isonicotinamide (Inam), caffeine (Caf), and theophylline (Tph).
Abstract: Baicalein (Bai) is one of the most important bioactive flavonoids isolated from the well-known traditional Chinese medicine called “Huang Qin”. Though it has broad therapeutic capability, the bioavailability is limited due to its poor solubility. In this study, we aimed to modulate its solubility through cocrystallization. Cocrystals of Bai with isoniazide (Inia), isonicotinamide (Inam), caffeine (Caf), and theophylline (Tph) were obtained. And different cocrystallization methods lead to different cocrystal phases for Inam and Tph. These cocrystals were characterized using powder X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, dynamic vapor sorption, and Fourier transform infrared spectroscopy. Among all the cocrystals studied, BaiCaf is found to be superior in powder dissolution and pharmacokinetic behavior. Area under the curve values of BaiCaf is improved by a factor of 4.1, and the bioavailability of baicalein is thus expected to be accordingly increased. Given that C...
TL;DR: In this paper, a series of lanthanide metal-organic frameworks (Ln-MOFs) have been solvothermally synthesized using an anthracene-derived dicarboxylate ligand.
Abstract: Series of lanthanide metal–organic frameworks (Ln-MOFs) have been solvothermally synthesized using an anthracene-derived dicarboxylate ligand. The synthesized Ln-MOFs (Ce, Tb, Dy) show characteristics of broad-band visible-light absorption and efficient photoinduced charge generation. For the first time, Ln-MOFs have been employed as visible-light photocatalysts for rhodamine B (RhB) degradation in the presence of oxidant of hydrogen peroxide (H2O2). Results show that these Ln-MOFs are highly efficient for visible-light-driven RhB degradation in aqueous solution. The degradation reactions show notable reaction rate constants. It is interesting to observe that the premixing between Ln-MOFs and H2O2 is vital to improve photocatalytic performance, indicating the advantage of porous MOF catalysts. This study not only presents rare examples of visible-light-driven MOF photocatalysts constructed from lanthanide ions, but also reveals that the H2O2-involved advanced oxidation process is feasible for enhancing ph...
TL;DR: In this article, three trinuclear complexes constructed from a naphthalenediol-based bis(Salamo)-type tetraoxime ligand (H4L1), [Cu3(L1)(OAc)2]·CH3OH (1), Zn3 (L1)OAc2(CH3H)2], 4CHCl3 (2), and [Cu2(L 1)Na(NO3)(CH3HO)] (3), and one dinuclear complex, [{Cu(L2)}2] (
Abstract: Three trinuclear complexes constructed from a naphthalenediol-based bis(Salamo)-type tetraoxime ligand (H4L1), [Cu3(L1)(OAc)2]·CH3OH (1), [Zn3(L1)(OAc)2(CH3OH)2]·4CHCl3 (2), and [Cu2(L1)Na(NO3)(CH3OH)] (3), and one dinuclear complex, [{Cu(L2)}2] (4), based on an unexpected ligand H2L2 derived from the cleavage of H4L1 have been synthesized and characterized by X-ray diffraction analyses. Different anionic sources, transition metal salts, and rationally controlled reaction conditions play important roles in the construction of the resulting complexes with variable coordination geometries (coordination number ranges from 4 to 7), and four types of supramolecular network were controlled by noncovalent interactions, such as hydrogen bond, π···π stacking, C–H···π, Cu···π, and halogen-related interactions. The fluorescence properties of H4L1 and its complexes were investigated, and 2 exhibits unique bright cyan–yellow visible fluorescent emissions in different solvents.
TL;DR: Liu et al. as discussed by the authors showed that Cd(NO3)2·4H2O with 4-pyrpoly-poly-2-ene (ppene) in the presence of benzene-1,2-dicarboxylic acid (1, 2-H2BDC), benzene -1, 3-Dicaroxidibenzoic acid (4, 4′-OBA), or 4-4′-oxidin-4-yl)bicyclo[2.2.
Abstract: Solvothermal reactions of Cd(NO3)2·4H2O with 4-pyr-poly-2-ene (ppene) in the presence of benzene-1,2-dicarboxylic acid (1,2-H2BDC), benzene-1,3-dicarboxylic acid (1,3-H2BDC), benzene-1,4-dicarboxylic acid (1,4-H2BDC), benzene-1,3,5-tricarboxylic acid (1,3,5-H3BTC), or 4,4′-oxidibenzoic acid (4,4′-H2OBA) afforded five Cd(II) coordination polymers [Cd(ppene)(1,2-BDC)]n (1), [Cd(ppene)(1,3-BDC)]n (2), [{Cd(ppene)(1,4-BDC)}·MeCN]n (3) (Liu et al. Inorg. Chem. Commun. 2015, 58, 1−4), [{Cd(ppene)(1,3,5-HBTC)}·0.5(ppene)]n (4), and [Cd(ppene)(4,4′-OBA)]n (5), respectively. Upon UV light irradiation, 1, 3, and 4 can undergo a double [2 + 2] cycloaddition reaction to yield their corresponding photoproducts including [Cd2(4-tp-3-lad)(1,2-BDC)2]n (1a, 4-tp-3-lad = 2,3,5,6-tetra(pyridin-4-yl)bicyclo[2.2.0]hexane), [{Cd2(4-tp-3-lad)(1,4-BDC)2}·2MeCN]n (3a), and [{Cd2(4-tp-3-lad)(1,3,5-HBTC)2}·(ppene)]n (4a) in a single-crystal-to-single-crystal manner. Compounds 1, 2, 4, 5, 1a, 3a, and 4a have been structurally charac...
TL;DR: In this article, a new rigid and symmetrical tetracarboxylic ligand 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine (H4TCPP) with aggregation-induced emission effect has been designed and synthesized.
Abstract: A new rigid and symmetrical tetracarboxylic ligand 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine (H4TCPP) with aggregation-induced emission effect has been designed and synthesized. By using such a ligand, a novel multifunctional metal–organic framework Zn-TCPP has been successfully constructed. The cross-linkage of dinuclear Zn2(COO)4 clusters and organic TCPP4– ligands results in the three-dimensional channel structure of Zn-TCPP, which has a four connected lvt topology with the point symbol of {42.84}. Zn-TCPP not only displays bright blue luminescence arising from the matrix coordination-induced emission effect of the TCPP4– ligand, but also exhibits effective detection for picric acid and Fe3+ ions. In addition, the activated Zn-TCPP possesses a highly porous framework with a Brunauer–Emmett–Teller surface area of 984 m2 g–1 and CO2 adsorption capacity up to 135 cm3 g–1 at 273 K and 732 mmHg. This work represents a successful example of constructing metal–organic frameworks with desired functions based o...
TL;DR: In this article, a series of new isostructural lanthanide metal-organic frameworks (Ln-MOFs), [Ln2(L)2(DMAC)2]·nH2O, have been isolated and a single-crystal X-ray diffraction analysis reveals that all complexes exhibit a rare (4, 8)-connected alb-4,8-P topology with binuclear [Eu2(COO)8]n secondary building units as 8connected nodes and H4L ligands as 4-connected nodes.
Abstract: A series of new isostructural lanthanide metal–organic frameworks (Ln-MOFs), [Ln2(L)2(DMAC)2]·nH2O [Ln = La (1), Pr (2), Nd (3), Sm (4), Eu (5), Gd (6), Tb (7), and Tm (8); H4L = 5-(bis(4-carboxybenzyl)amino)-isophthalic acid, DMAC = N,N′-dimethylacetamide], have been isolated. Single-crystal X-ray diffraction analysis reveals that all complexes exhibit a rare (4,8)-connected alb-4,8-P topology with binuclear [Eu2(COO)8]n secondary building units as 8-connected nodes and H4L ligands as 4-connected nodes. Two mixed-lanthanide analogues of single-lanthanide MOFs were designed and prepared [Ln = La0.93Eu0.02Tb0.05 (9) and Tm0.47Eu0.18Tb0.35 (10)] by way of careful regulation of the relative concentration of lanthanide ions which are able to emit pure white light. Luminescent sensing of complexes 3 and 5 has been investigated. Strikingly, complex 5 exhibits an excellent luminescent sensing to TNP with a high Ksv value of 3.58 × 104 M–1 and a low detection limit of 4.66 × 10–4 mM. Complex 3 reveals high select...
TL;DR: In this article, two new networks, namely, {[Cd(bpba)(H2bptc)1/2·H2O]}n (1), {[Co(BPba)(bdc) 1/2]n (2), where Hbpba = 3,5-bis(pyridin-4-ylmethoxy)benzoic acid, H4bPTc = 3.3′,5,5′-biphenyltetracarboxylate, H2bdc = 1,4
Abstract: Two new networks, namely, {[Cd(bpba)(H2bptc)1/2·H2O]}n (1), {[Co(bpba)(bdc)1/2]}n (2), where Hbpba = 3,5-bis(pyridin-4-ylmethoxy)benzoic acid, H4bptc = 3,3′,5,5′-biphenyltetracarboxylate, H2bdc = 1,4-benzenedicarboxylate, have been synthesized hydrothermally and characterized. Compound 1 is a three-dimensional net with a rare jea topology. The flexible pyridyl arms may afford a dimension extension in the crystal structure. While for compound 2 the flexible pyridyl arms are not involved in coordination, the Co(II) paddle-wheel secondary building units are bridged by the mixed ligands, bpba– and bdc2–, to furnish a two-dimensional layer. In addition, their heterogeneous catalytic oxidation activities toward methyl orange, methyl blue, neutral red, methylene blue, and safranine T (ST) in the presence of H2O2 are investigated in aqueous solution. The results suggested that the photocatalytic efficiency of ST is found to be 100% for MOF-2.
TL;DR: In this paper, the dihalomethane-halide H2C(X)−X···X− (X = Cl, Br) halogen bonding was detected in a series of the cis-PdX(CNCy){C(NHCy)═NHC6H2Me2NH2}]X•CH2X2 (X, Br), associates by single-crystal XRD followed by DFT calculations.
Abstract: The dihalomethane–halide H2C(X)–X···X– (X = Cl, Br) halogen bonding was detected in a series of the cis-[PdX(CNCy){C(NHCy)═NHC6H2Me2NH2}]X•CH2X2 (X = Cl, Br) associates by single-crystal XRD followed by DFT calculations. Although ESP calculations demonstrated that the σ-hole of dichloromethane is the smallest among all halomethane solvents (the maximum electrostatic potential is only 2.6 kcal/mol), the theoretical DFT calculations followed by Bader’s QTAIM analysis (M06/DZP-DKH level of theory) confirmed the H2C(X)–X···X– halogen bond in both the solid-state and gas-phase optimized geometries. The estimated bonding energy in H2C(X)–X···X– is in the 1.9–2.8 kcal/mol range.