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Branched surfactants exhibit a lower surface tension, excellent low defoaming performance, and better wetting ability compared with linear surfactants, making them promising for applications in industrial cleaning. In this study, 2-hexyl-1-decene (C8 olefin dimer), obtained from the dimerization of 1-octene, was used as the hydrophobe to synthesize branched nonionic surfactants via hydroxylation and ethoxylation. The hydroxylation of the C8 olefin dimer to synthesize 2-hexyldecane-1,2-diol (C8 BD) using H2O2 and HCOOH was investigated systematically. Under the optimal reaction conditions (H2O2/C8 olefin dimer molar ratio: 1.5, HCOOH/C8 olefin dimer molar ratio: 4.0, reaction time: 10 h, reaction temperature: 50 °C), the conversion of the C8 olefin dimer and selectivity toward C8 BD were found to reach 99.96 and 79.89%, respectively. Further, branched nonionic surfactants (C8 BDEn) were synthesized via ethoxylation of C8 BD with ethylene oxide and characterized using FTIR, LCMS, 1H NMR, and 13C NMR techniques. The presence of a tertiary hydroxyl group in C8 BD increases the reactivity of the primary hydroxyl group, leading to a narrower range of products and lower residual substrate content. The physicochemical properties and surface properties of C8 BDEn with different degrees of ethoxylation at various concentrations were investigated and compared with those of commercially available Guerbet alcohol polyoxyethylene ethers (C8 GAEO9 and C6 GAEO9). The results show that, compared with C8 GAEO9 and C6 GAEO9, C8 BDE6 displayed a higher surface activity with a lower equilibrium surface tension (27.14 mN·m-1), superior wettability with a smaller contact angle (39.2°), better emulsification performance with a longer emulsification time of 548 s, and excellent foaming properties (initial foam volume of 11.6 mL). This strategy of utilizing coal-based α-olefins for the synthesis of branched nonionic surfactants presents a route to prepare value-added fine chemicals from coal-based resources.
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Few studies have reported on the continuous evolution of dual-linker zeolitic imidazolate frameworks' (ZIFs) structure and morphology during the crystal growth process. Herein, we report the synthesis of a novel ZIF material with CHA topology (ZIF-301-eIm) via the combination of a small-sized 2-ethylimidazole (eIm) with the large-sized 5-chlorobenzimidazole ligand. A series of derivative materials with distinct structures and morphologies were obtained via two pathways: (1) insufficient amount of eIm with prolonged crystallization time (pathway A) and (2) sufficient amount of eIm with prolonged crystallization time (pathway B). Various characterization techniques revealed the continuous evolution of structure and morphology during the crystal growth process. Insufficient amount of eIm and crystallization time (crystallization pathway A) led to ZIF-301-eIm derivatives with defective and open structures alongside an aggregated morphology of nanoparticles. Prolonging the crystallization time allowed small-sized eIm ligands to gradually fill into the framework, resulting in the formation of ZIF-301-eIm-A5 characterized by complete but dense structures with a perfect polyhedral morphology. Remarkably, a sufficient amount of eIm during synthesis (crystallization pathway B) formed ZIF-301-eIm-B1 with a similar structure and morphology to ZIF-301-eIm-A5 in just 1 day. ZIF-301-eIm-B3, with intact, dense structures, exhibits superior acetone/butanol separation performance compared to ZIF-301-eIm-A3 due to small pore windows and large cages facilitating selective adsorption of acetone through exclusion separation.
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The bulk radical polymerization of bis(aziridine) with molten elemental sulfur resulted in brittle, cross-linked polymers. However, when the bis(aziridine) was treated with elemental sulfur in the presence of an organobase, the ring-opening reaction of aziridine with oligosulfide anions occurred, leading to the formation of linear polymers by step-growth polymerization. These newly synthesized polymers possess repeating units containing a sulfonamide or amide functional moiety and oligosulfide bonds with an average sulfur segment of about two. A small molecular model reaction confirmed the nucleophilic addition reaction of elemental sulfur to aziridine. It was verified that S-S dynamic bond exchange takes place in the presence of an organic base within the linear chains. The mixture of the synthesized polysulfides with pyridine exhibits exceptional adhesive properties when applied to steel, and aluminum substrates. Notably, these prepared adhesives displayed good reusability due to the dynamic S-S exchange and complete recyclability due to their solution processability. This elemental sulfur-involved polymerization approach represents an innovative method for the synthesis of advanced sulfur-containing polymers, demonstrating the potential for various applications in adhesives and beyond.
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Type 2 diabetes (T2D) is characterized by insulin resistance (IR), often accompanied by inflammation. Macrophage activation acts as an inflammatory response, which is characterized by macrophage recruitment in the initial stage. Ginsenoside Rb1 (Rb1) is a main active ingredient, which is known for its fat-reducing, anti-inflammatory effects. To clarify that Rb1 regulates macrophage activation in adipose tissue and improves tissue inflammation, network pharmacology and molecular docking were used for target prediction and preliminary validation. By constructing the co-culture model of adipose-derived stem cells (ADSC) and primary macrophage (PM), the body adipose tissue microenvironment was simulated to observe the adipogenesis degree of adipocytes under the effect of Rb1. The levels of cytokines, macrophage polarization, and protein or RNA expression in the inflammatory signaling pathway were finally detected. The results showed that 89 common targets of T2D-Rb1 were obtained after their intersection. Furthermore, according to the results of the KEGG pathway and PPI analysis, PTGS2 (COX-2) is the downstream protein of PPARγ-NF-κB. The molecular binding energy of PPARγ-Rb1 is -6.8 kcal/mol. Rb1 significantly inhibited the increase in MCP-1, TNF-α, and IL-1ß induced by hypertrophic adipocytes supernatant and promoted the expression of IL-10. Rb1 inhibited the activation of inflammatory macrophages and PM migration and upregulated PPARγ expression with the blocking of NF-κB activation. Additionally, Rb1 promoted the expression of IRS1 and PI3K in the insulin signal pathway, which had a similar effect with ROS. Therefore, Rb1 might affect macrophage activation through PPARγ, which might alleviate obese insulin resistance in T2D early stage.
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Diabetes Mellitus Tipo 2 , Resistência à Insulina , Humanos , PPAR gama/metabolismo , Ativação de Macrófagos , NF-kappa B/metabolismo , Diabetes Mellitus Tipo 2/complicações , Simulação de Acoplamento Molecular , Obesidade/metabolismo , Inflamação/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Ligação a Retinoblastoma/metabolismoRESUMO
A new class of ricinoleic acid-derived branched surfactant with a Y-shaped structure (ethoxylated monohydroxy stearic acid methyl ester, 12-HMEEn) was synthesized and characterized by introducing a polyoxyethylene head group in the hydroxyl position inside the molecule. The physicochemical properties and surface activities of 12-HMEEn with different degrees of ethoxylation at various concentrations were studied. The typical Y-shaped structure of the molecule facilitates its adsorption at the interface, which provides an excellent surface activity and affects its surfactant properties significantly. The dynamic contact angle, wettability, foaming properties, and compatibility tests of 12-HMEEn showed that it has good wetting performance, low foaming and fast defoaming properties, and good compatibility in formulation applications, indicating that the surfactant has potential application in industrial cleaning.
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Surfactantes Pulmonares , Tensoativos , Ésteres , Excipientes , Polietilenoglicóis , Propriedades de Superfície , Tensoativos/química , MolhabilidadeRESUMO
Obesity is often accompanied by chronic low-grade inflammation, which aggravates the disorder of lipid metabolism and leads to insulin resistance (IR). Macrophage activation plays an important role in inflammation. Ginsenoside Compound K (CK) is an active metabolite of ginsenoside Rb1, which is adopting to an anti-inflammatory effective substance. In order to clarify the mechanism of ginsenoside CK on the regulation of macrophage activation in adipose tissue, the macrophage model was incubated with the supernatant of hypertrophic adipocytes, and the co-culture models of Raw264.7 and 3T3-L1 were established. The levels of related cytokines, macrophage polarization and protein expression in inflammatory signaling pathway were measured. The results showed that ginsenoside CK significantly inhibited the increase of MCP-1 and TNF-α induced by the supernatant of hypertrophic adipocytes, promoted the expression of IL-10, inhibited the activation of inflammatory macrophages and increased the expression of anti-inflammatory macrophages. Similarly, ginsenoside CK inhibited the migration of Raw264.7, blocked the activation of NF-κB, and up-regulated the expression of PPARγ. In addition, ginsenoside CK also promotes the expression of IRS-1 in insulin signal pathway. The experimental results proved that ginsenoside CK plays a crucial role in alleviating inflammation and insulin resistance in obesity, and inhibits macrophage activation through the key protein PPARγ.
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Resistência à Insulina , Ativação de Macrófagos , Células 3T3-L1 , Animais , Ginsenosídeos , Humanos , Camundongos , Obesidade , PPAR gama , Células RAW 264.7RESUMO
Using bulky amides as the structure-directing agents (SDAs) is an alternative synthetic strategy for the exploration of crystalline large pore (≥12-membered ring) zeolitic imidazolate frameworks (ZIFs). Specifically, by using the bulky amides, dibutylformamide (DBF) and dipropylformamide (DPF) as solvent and imidazole (Im) as a ligand, two ZIFs mimicking the CAN and AlPO-5 (AFI) zeotypes with 12-membered ring (MR) pore openings were synthesized, and denoted as CAN-[Zn(Im)2] and AFI-[Zn(Im)2], respectively. These two materials are the first known examples of Zn(Im)2 polymorphs with 12-MR pores and AFI-[Zn(Im)2] has the largest pore apertures reported to date for ZIF materials. The concept that the bulky amides used were not simply acting as the solvent, but were in fact acting as SDAs or templates during the synthesis of the large pore ZIFs, was suggested by the closeness of the geometrical fit between the guest DBF and the can cages (composite building units) of the CAN-[Zn(Im)2].
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A new layered zirconium phosphate material has been synthesized ionothermally using N-ethylpyridinium (Epy) bromide as both the solvent and the template, and its structure has been solved from synchrotron X-ray powder diffraction data using the charge-flipping routine implemented in Superflip. Rietveld refinement coupled with difference electron density map analysis was used to locate the organic cations between the layers. In the final stages of refinement, it became clear that not only ethylpyridinium but also pyridinium ions were present between the zirconium phosphate layers. These findings were then corroborated using elemental analysis, TGA, and solid-state (13)C CP/MAS NMR data.
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The ability to obtain a maximum loading of inorganic nanoparticles while maintaining uniform dispersion in the polymer is the key to the fabrication of mixed-matrix membranes with high pervaporation performance in bioalcohol recovery from aqueous solution. Herein, we report the simultaneous spray self-assembly of a zeolitic imidazolate framework (ZIF)-polymer suspension and a cross-linker/catalyst solution as a method for the fabrication of a well-dispersed ZIF-8-PDMS nanohybrid membrane with an extremely high loading. The ZIF-8-PDMS membrane showed excellent biobutanol-permselective pervaporation performance. When the ZIF-8 loading was increased to 40 wt%, the total flux and separation factor could reach 4846.2 g m(-2) h(-1) and 81.6, respectively, in the recovery of n-butanol from 1.0 wt% aqueous solution (80 °C). This new method is expected to have serious implications for the preparation of defect-free mixed-matrix membranes for many applications.
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Biocombustíveis , Butanóis/metabolismo , Dimetilpolisiloxanos/química , Membranas Artificiais , Nanoestruturas/química , Zeolitas/química , Butanóis/química , Gases/química , Imidazóis/química , Permeabilidade , Temperatura , Água/químicaRESUMO
Organic amides as solvents and structure directing agents (SDAs) are crucial for synthesizing zeolitic imidazolate frameworks (ZIFs). However, current research focuses only on the use of short alkyl-chain amides as solvents/SDAs. Here, we investigate the role of amides with varying alkyl-chain lengths on the structures and topologies of Zn(Im)2 polymorphs. Using short alkyl-chain amides as solvents, the Zn(Im)2 topological structures are affected by the synthesis conditions, leading to "one SDA/multiple topological structures". In contrast, when long alkyl-chain amides are used as solvents, the Zn(Im)2 topological structures are essentially unaffected by other synthesis conditions. Thus, long alkyl-chain amides are shown for the first time to exhibit a significant template role, leading to "one template/one topological structure". Specifically, the use of long alkyl-chain N,N-dimethyl-Cn amides (abbreviated as DM-Cn amides, n = 3, 4, 6, 8, and 10) can lead to only DTF-type Zn(Im)2 frameworks under broad crystallization conditions. Single-crystal X-ray diffraction confirmed that the exquisite structural compatibility between long alkyl-chain DM-Cn amides and the DFT-type Zn(Im)2 framework results in a highly regular head-to-tail arrangement of amides along the (kaa-lov) n chain of the DFT framework. The template role for long alkyl-chain amides was further identified to be multiple C-H···π interactions between DM-Cn amides and Zn(Im)2 frameworks thanks to molecular simulations.
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Metal-organic frameworks (MOFs) are an extremely important class of porous materials with many applications. The metal centers in many important MOFs are zinc cations. However, their Zn environments have not been characterized directly by (67)Zn solid-state NMR (SSNMR) spectroscopy. This is because (67)Zn (I=5/2) is unreceptive with many unfavorable NMR characteristics, leading to very low sensitivity. In this work, we report, for the first time, a (67)Zn natural abundance SSNMR spectroscopic study of several representative zeolitic imidazolate frameworks (ZIFs) and MOFs at an ultrahigh magnetic field of 21.1 T. Our work demonstrates that (67)Zn magic-angle spinning (MAS) NMR spectra are highly sensitive to the local Zn environment and can differentiate non-equivalent Zn sites. The (67)Zn NMR parameters can be predicted by theoretical calculations. Through the study of MOF-5 desolvation, we show that with the aid of computational modeling, (67)Zn NMR spectroscopy can provide valuable structural information on the MOF systems with structures that are not well described. Using ZIF-8 as an example, we further demonstrate that (67)Zn NMR spectroscopy is highly sensitive to the guest molecules present inside the cavities. Our work also shows that a combination of (67)Zn NMR data and molecular dynamics simulation can reveal detailed information on the distribution and the dynamics of the guest species. The present work establishes (67)Zn SSNMR spectroscopy as a new tool complementary to X-ray diffraction for solving outstanding structural problems and for determining the structures of many new MOFs yet to come.
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The flexibility and guest-responsive behavior of some metal-organic frameworks (MOFs) indicate their potential in the fields of sensors and molecular recognition. As a subfamily of MOFs, the flexible zeolitic imidazolate frameworks (ZIFs) typically feature a small displacive transition due to the rigid zeolite topology. Herein, an atypical reversible displacive transition (6.4 Å) is observed for the sodalite (SOD) cage in flexible ZIF-65(Zn), which represents an unusually large breathing effect compared to other ZIFs. ZIF-65(Zn) exhibits a stepwise II â III â I expansion between an unusual ellipsoidal SOD cage (8.6 Å × 15.9 Å for II) and a spherical SOD cage (15.0 Å for I). The breathing behavior of ZIF-65(Zn) varies depending on the nature of the guest molecules (polarity and shape). Computational simulations are employed to rationalize the differences in the breathing behavior depending on the structure of the ZIF-65(Zn) cage and the nature of the guest-associated host-guest and guest-guest interactions.
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Estruturas Metalorgânicas , Zeolitas , Imidazóis/química , Estruturas Metalorgânicas/química , Zeolitas/química , Zinco/químicaRESUMO
To understand the unprecedented difference between 6-endo and 5-exo selectivity in hypervalent iodine (III) promoted fluorocyclization of unsaturated carboxylic acids or alcohols by difluoroiodotoluene, density functional theory (DFT) studies have been performed to systematically compare both the previous proposed "fluorination first and cyclization later" mechanism and the alternative "cyclization first and fluorination later" mechanism. Our results revealed that the selectivity is mechanism-dependent. The unsaturated alcohol prefers the fluorination first and the 6-endo-tet cyclization later pathway, leading to the experimentally observed 6-endo ether product. In contrast, the unsaturated carboxylic acid plausibly undergoes the 5-exo-trig cyclization first and the fluorination later to the experimentally observed 5-exo lactone product. The pK a property of the functional group of the substrate is found to play a key role in determining the reaction mechanism. The provided insights into the mechanism-dependent selectivity should help advance the development of fluorocyclization reactions with hypervalent iodine reagents.
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Alkylbenzenes have a wide range of uses and are the most demanded aromatic chemicals. The finite petroleum resources compels the development of production of alkylbenzenes by non-petroleum routes. One-pass selective conversion of benzene and syngas to alkylbenzenes is a promising alternative coal chemical engineering route, yet it still faces challenge to industrialized applications owing to low conversion of benzene and syngas. Here we presented a Cu-ZnO-Al2O3/ZSM-5 bifunctional catalyst which realizes one-pass conversion of benzene and syngas to alkylbenzenes with high efficiency. This bifunctional catalyst exhibited high benzene conversion (benzene conversion of 50.7%), CO conversion (CO conversion of 55.0%) and C7&C8 aromatics total yield (C7&C8 total yield of 45.0%). Characterizations and catalytic performance evaluations revealed that ZSM-5 with well-regulated acidity, as a vital part of this Cu-ZnO-Al2O3/ZSM-5 bifunctional catalyst, substantially contributed to its performance for the alkylbenzenes one-pass synthesis from benzene and syngas due to depress methanol-to-olefins (MTO) reaction. Furthermore, matching of the mass ratio of two active components in the dual-function catalyst and the temperature of methanol synthesis with benzene alkylation reactions can effectively depress the formation of unwanted by-products and guarantee the high performance of tandem reactions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10562-021-03617-5.
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Obesity disrupts the immune system of adipose tissue, and the activation of its macrophages constantly infiltrating adipose tissue is a crucial cause of insulin resistance induced by obesity. We previously reported for the first time in vitro that the antidiabetic effect of CK may be through the inhibition of macrophage activation and we further explored the specific mechanism in vivo. In order to clarify it, the C57BL/6J mice were fed with a high fat diet and then administered with CK orally. The related biochemical indices were detected, the inflammatory factors in serum and tissues were measured, and the related protein expression levels in insulin pathways and inflammatory signaling pathways were observed. The results showed that CK could dose-dependently reduce macrophage M1-type inflammatory factor expression in serum and adipose tissue, improve insulin resistance and glucose tolerance effectively, upregulate PPARγ expression and block TLR4/TRAF6/TAK1/NF-κB activation in obese mice. In addition, CK promoted the expression of IRS1/PI3K/AKT. Furthermore, our study showed that ginsenoside CK could improve insulin resistance by reducing inflammation through the PPARγ/NF-κB signaling pathway, which implies that ginsenoside CK may be an effective agent against obesity or early diabetes.
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Resistência à Insulina , Tecido Adiposo/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Ginsenosídeos , Inflamação/metabolismo , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , PPAR gama/genética , PPAR gama/metabolismo , Fosfatidilinositol 3-Quinases/metabolismoRESUMO
Less is more: an open-framework zirconium phosphate with unusual 7-ring channels was synthesized ionothermally from a deep-eutectic solvent. This small-pore material displays a CO(2)/CH(4) adsorption ratio (17.3 at 1 bar) that is significantly higher than that of typical 8-ring materials, making it highly attractive for CO(2)/CH(4) separations.
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Dióxido de Carbono/química , Metano/química , Zircônio/química , Adsorção , Conformação MolecularRESUMO
In an attempt to synthesize novel zirconium phosphate materials, a series of syntheses have been performed in a deep eutectic solvent (DES), composed of tetrapropylammonium bromide (TPABr) and oxalic acid. As a result, this DES does not act as a template provider in reaction probably owing to the steric effects of the longer chains of the TPA cation, and only the α-Zr(HPO(4))(2)·H(2)O (α-ZrP) phase has been achieved. However, after organic amine was added to the initial reaction mixture in a normal way, the additives did act as a template to induce the zirconium phosphate framework. For example, with 1,4-dimethylpiperazine as an additive, a novel layered compound, [C(6)H(16)N(2)](0.5)Zr(H(0.5)PO(4))(2)·H(2)O (denoted as ZrPO(4)-DES8) was obtained. Its structure was determined from single-crystal X-ray diffraction (XRD) data and consists of zirconium phosphate layers with the protonated 1,4-dimethylpiperazine and water molecules in between. Interestingly, the two layered materials as additives in a liquid lubricant exhibit excellent friction behavior with higher load-carrying and antiwear capacities in comparison to typical lubricant additives such as MoS(2) and graphite, increase the P(B) value of the base oil by 27.2% and 8.5%, and decrease the wear scar diameter of the base oil by 43% and 36%, respectively. Scanning electron microscopy, XRD, and energy-dispersive X-ray spectrometry are used to investigate the lubricant behavior of those materials.
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Two novel zirconium phosphate compounds, |(C(9)H(8)N)(4)(H(2)O)(4)|[Zr(8)P(12)O(40)(OH)(8)F(8)] and |(C(9)H(8)N)(2)|[Zr(2)P(2)O(6)(OH)(4)F(4)], designated as ZrPOF-Q1 and ZrPOF-Q2, respectively, have been synthesized hydrothermally in the presence of quinoline and HF and characterized by elemental and thermogravimetric analyses, UV-vis spectroscopy, and scanning electron microscopy. Their crystal structures were determined from powder X-ray diffraction data using a charge-flipping algorithm. The ZrPOF-Q1 structure [P1, a = 10.7567(1) A, b = 13.8502(1) A, c = 14.8995(1) A, alpha = 109.6(1) degrees, beta = 101.1(1) degrees, and gamma = 100.5(1) degrees] consists of zirconium phosphate layers with quinolinium ions in between. The layers are unusual in that isolated ZrO(2)F(4) octahedra are anchored on both sides of the layer and protrude into the interlayer space. The ZrPOF-Q2 structure [P1, a = 7.7058(1) A, b = 12.3547(1) A, c = 6.5851(1) A, alpha = 97.0(1) degrees, beta = 89.7(1) degrees, and gamma = 101.9(1) degrees] consists of zirconium phosphate chains with an unusual Zr/P ratio of 1.0, interspersed with quinolinium ions. Both materials are stable up to 250 degrees C and exhibit interesting photoluminescence in the UV-vis spectral region. This is attributed to the protonated quinoline molecules, which are an integral part of both structures.
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The title compound, [Zn(C(2)H(8)N(2))(3)](SiF(6)), was synthesized ionothermally using choline chloride-imidazolidone as solvent and template provider. In the crystal structure, the anions and cations are located on special positions of site symmetry 3.2 and show a typical octa-hedral geometry. The Zn(II) ion is coordinated by six N atoms from three ethyl-enediamine mol-ecules. The crystal structure displays weak hydrogen bonding between [SiF(6)](2-) anions and the ethyl-enediamine NH hydrogen atoms.
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On their best behavior: Three zirconium compounds with one-, two-, and three-dimensional structures have been successfully synthesized by the ionothermal approach. The 3D zirconium phosphate (see picture; F green, H white, O red, P pink, Zr yellow) exhibits high catalytic performance, with a cyclohexane conversion ratio of 32% and cyclohexanone selectivity of up to 83%.