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Highly organized π-aggregate architectures can strongly affect electronic couplings, leading to important photophysical behaviors. With the escalating interest in two-dimensional (2D) materials attributed to their exceptional electronic and optical characteristics, there is growing anticipation that 2D radial-π-stacks built upon radial π-conjugation nanorings, incorporating intra- and inter-ring electronic couplings within the confines of a 2D plane, will exhibit superior topological attributes and distinct properties. Despite their immense potential, the design and synthesis of 2D π-stacks have proven to be a formidable challenge due to the insufficient π-π interactions necessary for stable stacking. In this study, we present the successful preparation of single-layer 2D radial-π-stacks in a solution. Pillar-shaped radially π-conjugated [4]cyclo-naphthodithiophene diimide ([4]C-NDTIs) molecules were tetragonally arranged via in-plane intermolecular π-π interactions. These 2D π-stacks have a unique topology that differs from that of conventional 1D π-stacks and exhibit notable properties, such as acting as a 2D template capable of absorbing C60 guest molecules and facilitating the formation of 2D radial-π-stacks comprising [4]C-NDTI-C60 complexes, rapid exciton delocalization across the 2D plane, and efficient excitation energy funneling towards a trap.
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The present study aimed to evaluate the effect of king oyster mushroom (Pleurotus eryngii) root waste and soybean meal co-fermented protein (CFP) on growth performance, feed utilization, immune status, hepatic and intestinal health of largemouth bass (Micropterus salmoides). Largemouth bass (12.33 ± 0.18 g) were divided into five groups, fed with diets containing 0 %, 5 %, 10 %, 15 % and 20 % CFP respectively for 7 weeks. The growth performance and dietary utilization were slightly improved by the supplementation of CFP. In addition, improved immunoglobulin M (IgM) content and lysozyme activity in treatments confirm the enhancement of immunity in fish by the addition of CFP, especially in fish fed 20 % CFP (P < 0.05). Furthermore, CFP significantly improved liver GSH (glutathione) content in groups D10 and D15 (P < 0.05), and slightly improved total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity while slightly reduced malondialdehyde (MDA) content. Simultaneously, the upregulation of lipolysis-related genes (PPARα, CPT1 and ACO) expression and downregulation of lipid synthesis-related genes (ACC and DGAT1) expression was recorded in the group D20 compared with the control (P < 0.05), which were consistent with the decreased liver lipid contents, suggests that lipid metabolism was improved by CFP. In terms of intestinal structural integrity, ameliorated intestinal morphology in treatments were consistent with the upregulated Occludin, Claudin-1 and ZO-1 genes expression. The intestinal pro-inflammatory cytokines (TNF-α and IL-8) expression were suppressed while the anti-inflammatory cytokines (IL-10 and TGF-ß) were activated in treatments. The expression of antimicrobial peptides (Hepcidin-1, Piscidin-2 and Piscidin-3) and intestinal immune effectors (IgM and LYZ) were slightly up-regulated in treatments. Additionally, the relative abundance of intestinal beneficial bacteria (Firmicutes) increased while the relative abundance of potential pathogenic bacteria (Fusobacterium and Proteobacteria) decreased, which indicated that the intestinal microbial community was well-reorganized by CFP. In conclusion, dietary CFP improves growth, immunity, hepatic and intestinal health of largemouth bass, these data provided a theoretical basis for the application of this novel functional protein ingredient in fish.
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Alimentación Animal , Lubina , Dieta , Suplementos Dietéticos , Glycine max , Hígado , Pleurotus , Animales , Lubina/inmunología , Lubina/crecimiento & desarrollo , Alimentación Animal/análisis , Dieta/veterinaria , Pleurotus/química , Glycine max/química , Hígado/inmunología , Hígado/efectos de los fármacos , Hígado/metabolismo , Suplementos Dietéticos/análisis , Intestinos/inmunología , Intestinos/efectos de los fármacos , Fermentación , Inmunidad Innata/efectos de los fármacos , Distribución Aleatoria , Raíces de Plantas/química , Relación Dosis-Respuesta a DrogaRESUMEN
The properties of functional materials based on organic π-conjugated systems are governed extensively by intermolecular interactions between π-molecules. To establish clear relationships between supramolecular structures and functional properties, it is essential to attain structurally well-defined π-stacks, particularly in solution, as this enables the collection of valuable spectroscopic data. However, precise control and fine-tuning of π-stacks pose significant challenges due to the weak and bidirectional nature of π-π stacking interactions. This article introduces the concept of "frustrated π-stacking," strategically balancing attractive (π-π interaction) and repulsive (steric hindrance) forces in self-assembly to exert control over the sizes, sequences of π-stacks, and slip-stacked structures. These research efforts contribute to a deeper understanding of the correlation between π-stacks and their properties, thereby providing useful insights for the development of molecular materials with the desired performance.
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Two rigid ß-elimination immune PCcarbeneP pincer ligands, differing in their electron donor properties by variation of the substitution pattern on the aromatic linker arms, were complexed to ruthenium to form the dichlorides LRRuCl2 (R = H or NMe2). These compounds were converted to hydrido chlorides by treatment with dihydrogen (H2) and a base. By converting to tert-butoxide derivatives in situ under an atmosphere of H2, the poly hydride PCalkylP complexes LHRRu(H)3 compounds were generated. In these complexes, H2 has added across the RuîC bond in the PCcarbeneP starting materials. The polyhydrides are dynamic in solution and extensive NMR studies helped to elucidate the speciation and fluxional processes operative in this dynamic system. The polyhydride complexes react rapidly with CO2 to give the PCcarbeneP formato hydride complexes LRRu(H)-κ2-O2CH. For R = H, the 1,2-hydride shift from the anchoring alkyl of the PCalkylP carbon to the metal is reversible, but for R = NMe2 it is irreversible. The CO2 incorporated into the formato ligand of these compounds exchanges with free CO2via a bimolecular mechanism that is more rapid for R = NMe2 than for R = H; plausible explanations for this observation are proffered. Experiments designed to evaluate the efficacy of the R = NMe2 formato hydride complex as a catalyst precursor for CO2 hydrogenation to formate salts reveal poor performance in comparison to state-of-the-art ruthenium-based catalysts. This is due primarily to the precipitation of a dimeric µ-κ2-κ1-CO3 carbonate complex that is not an active catalyst for the reaction.
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In this work, density functional theory (DFT) calculations were conducted to investigate a series of transition metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ru, Rh, Pd, Ag, Hf, Ta, Os, Ir, and Pt) as single-atom components introduced into Ti-BPDC (BPDC=2,2'-bipyridine-5,5'-dicarboxylic acid) as catalysts (M/Ti-BPDC) for the photocatalytic reduction of CO2. The results show that Fe/Ti-BPDC is the most active candidate for CO2 reduction to HCOOH due to its small limiting potential (-0.40â V). Ag, Cr, Mn, Ru, Zr, Nb, Rh, and Cu modified Ti-BPDC are also active to HCOOH since their limiting potentials are moderate although the reaction mechanisms are different across these materials. Most of the studied catalysts show poor activity and selectivity to CO product because the stability of *COOH/*OCOH intermediates is significantly weaker than *OCHO/*HCOO species. The moderate binding strength of *CO on Pd/Ti-BPDC is responsible for its superior catalytic activity toward CH3OH generation. Electronic structural analysis was performed to uncover the origin of the activity trend for CO2 reduction to different products on M/Ti-BPDC. The calculation results indicate that the activity and selectivity of CO2 photoreduction can be effectively tuned by designing single-atom metal-based MOF catalysts.
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Bacterial cellulose, as a kind of natural biopolymer produced by bacterial fermentation, has attracted wide attention owing its unique physical and chemical properties. Nevertheless, the single functional group on the surface of BC greatly hinders its wider application. The functionalization of BC is of great significance to broaden the application of BC. In this work, N-acetylated bacterial cellulose (ABC) was successfully prepared using K. nataicola RZS01-based direct synthetic method. FT-IR, NMR and XPS confirmed the in-situ modification of BC by acetylation. The SEM and XRD results demonstrated that ABC has a lower crystallinity and higher fiber width compare with pristine 88 BCE % cell viability on NIH-3 T3 cell and near zero hemolysis ratio indicate its good biocompatibility. In addition, the as-prepared acetyl amine modified BC was further treated by nitrifying bacteria to enrich its functionalized diversity. This study provides a mild in-situ pathway to construct BC derivatives in an environmentally friendly way during its metabolism.
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Bacterias , Celulosa , Espectroscopía Infrarroja por Transformada de Fourier , Bacterias/metabolismo , Fermentación , Celulosa/químicaRESUMEN
Natural light-harvesting (LH) systems can divide identical dyes into unequal aggregate states, thereby achieving intelligent "allocation of labor". From a synthetic point of view, the construction of such kinds of unequal and integrated systems without the help of proteinaceous scaffolding is challenging. Here, we show that four octatetrayne-bridged ortho-perylene diimide (PDI) dyads (POPs) self-assemble into a quadruple assembly (POP)4 both in solution and in the solid state. The two identical PDI units in each POP are compartmentalized into weakly coupled PDIs (P520) and closely stacked PDIs (P550) in (POP)4 . The two extreme pools of PDI chromophores were unambiguously confirmed by single-crystal X-ray crystallography and NMR spectroscopy. To interpret the formation of the discrete quadruple assembly, we also developed a two-step cooperative model. Quantum-chemical calculations indicate the existence of multiple couplings within and across P520 and P550, which can satisfactorily describe the photophysical properties of the unequal quadruple assembly. This finding is expected to help advance the rational design of dye stacks to emulate functions of natural LH systems.
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The reliable self-assembly of microporous metal-phosphonate materials remains a longstanding challenge. This stems from, generally, more coordination modes for the functional group allowing more dense structures, and stronger bonding driving less crystalline products. Here, a novel orthogonalized aryl-phosphonate linker, 1,3,5-tris(4'-phosphono-2',6'-dimethylphenyl) benzene (H6 L3) has been used to direct formation of open frameworks. The peripheral aryl rings of H6 L3 are orthogonalized relative to the central aromatic ring giving a tri-cleft conformation of the linker in which small aromatic molecules can readily associate. When coordinated to magnesium ions, a series of porous crystalline metal-organic, and hydrogen-bonded metal-organic frameworks (MOFs, HMOFs) are formed (CALF-41 (Mg), HCALF-42 (Mg), -43 (Mg)). While most metal-organic frameworks are tailored based on choice of metal and linker, here, the network structures are highly dependent on the inclusion and structure of the guest aromatic compounds. Larger guests, and a higher stoichiometry of metal, result in increased solvation of the metal ion, resulting in networks with connectivities increasingly involving hydrogen-bonds rather than direct phosphonate coordination. Upon thermal activation and aromatic template removal, the materials exhibit surface areas ranging from 400-600â m2 /g. Self-assembly in the absence of aromatic guests yields mixtures of phases, frequently co-producing a dense 3-fold interpenetrated structure (1). Interestingly, a series of both more porous (530-900â m2 /g), and more robust solids is formed by complexing with trivalent metal ions (Al, Ga, In) with aromatic guest; however, these are only attainable as microcrystalline powders. The polyprotic nature of phosphonate linkers enables structural analogy to the divalent analogues and these are identified as CALF-41 analogues. Finally, insights to the structural transformations during metal ion desolvation in this family are gained by considering a pair of structurally related Co materials, whose hydrogen-bonded (HCALF-44 (Co)) and desolvated (CALF-44 (Co)) coordination bonded networks were fully structurally characterized.
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This study explores the effect of a thione/selone ligand on the cell toxicity (in vitro) and light activity of diimine Re(CO)3+ complexes. Six rhenium(I) complexes with general formula fac-[Re(CO)3(N,N')X]+ were prepared, where X = 2-mercapto-1-methylimidazole (methimazole; MMI), and 1-methylimidazole-2-selone (MSeI); N,N' = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen) and 2,9-dimethyl-1,10-phenanthroline (dmphen). Their triflate salts were characterized using single-crystal X-ray diffraction, 1H, 13C and 2D NMR, UV-vis and vibrational spectroscopy. Their cytotoxic properties were tested, showing significant cytotoxicity (IC50 = 8.0-55 µM) towards the human breast cancer cell line MDA-MB-231. The half-inhibitory concentration (IC50) for fac-[Re(CO)3(dmphen)(MMI)]+, the most toxic complex in this series (8.0 ± 0.2 µM), was comparable to that of the corresponding aqua complex fac-[Re(CO)3(dmphen)(H2O)]+ with IC50 = 6.0 ± 0.1 µM. The fac-[Re(CO)3(bpy)(MMI/MSeI)]+ complexes were somewhat less toxic towards the human embryonic kidney cell line HEK-293 T after 48 h of exposure. The stability of the complexes upon irradiation was monitored using UV-vis spectroscopy, with no CO released when exposed to UV-A light (λ = 365 nm).
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Antineoplásicos , Renio , Selenio , Humanos , Renio/química , Metimazol , Células HEK293 , Antineoplásicos/farmacologíaRESUMEN
Designing transition metal-oxide-based bifunctional electrocatalysts with excellent activity and stability for OER/HER to achieve efficient water splitting is of great importance for renewable energy technologies. Herein, a highly efficient bifunctional catalysts with oxygen-rich vacancies of nickel-decorated RuO2 (NiRuO2-x) prepared by a unique one-pot glucose-blowing approach were investigated. Remarkably, the NiRuO2-x catalysts exhibited excellent HER and OER activity at 10 mA cm-2 in alkaline solution with only a minimum overpotential of 51 mV and 245 mV, respectively. Furthermore, the NiRuO2-x overall water splitting exhibited an ultra-low voltage of 1.6 V to obtain 10 mA cm-2 and stability for more than 10 h. XPS measurement and theoretical calculations demonstrated that the introduction of Ni-dopant and oxygen vacancies make the d-band center to lie close to the Fermi energy level, the chemical bonds between the active site and the adsorbed oxygen intermediate state are enhanced, thereby lowering the reaction activation barriers of HER and OER. The assembly of solar-driven alkaline electrolyzers facilitate the application of the NiRuO2-x bifunctional catalysts.
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Photocatalytic technology in eliminating organic pollutants is considered to be one of the most promising technologies to solve environmental issues. However, the low catalytic activity exhibited by Titanium dioxide (TiO2) limits its further application. In order to enhance the photocatalytic activity, structural regulation of TiO2 is designed by chemical reduction method to promote the production of massive Ti3+ and oxygen vacancies (OVs), these defects can serve as inter-band level of semiconductor to enhance photon capture and transfer efficiency of photogenerated charge. The samples show strong light absorption ability, which leads to excellent photocatalytic activity for various organic pollutants degradation. Results showed robust degradation of MO, RhB, DCP and TC under UV irradiation within 60 min. Estimated quantum yields of as-synthesized TiO2 systems for removing representative pollutants are calculated, which indicates higher reactivity than commercial TiO2. The XPS, TEM, photoelectrochemical analysis and EPR results intuitive reveal the micro-morphology, band structure and active species of Ti3+ doped defective TiO2. This work can provide an essential reference for structural regulation and composition of oxide semiconductor since the methodology could be freely applicable to other systems.
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Contaminantes Ambientales , Luz , Óxidos , Oxígeno , Fotólisis , Titanio/químicaRESUMEN
Designing and modifying nanoporous metal foils to make them suitable for supercapacitor and catalysis is significant but challenging. In this work, CuxO nanoflakes have been successfully in situ grown on nanoporous Cu foil via a facile electrooxidation method. A Ga-assisted surface Ga-Cu alloying-dealloying is adopted to realize the formation of a nanoporous Cu layer on the flexible Cu foil. The following electrooxidation, at a constant potential, modifies the nanoporous Cu layer with CuxO nanoflakes. The optimum CuxO/Cu electrode (O-Cu-2h) delivers the maximum areal capacitance of 0.745 F cm-2 (410.27 F g-1) at 0.2 mA cm-2 and maintains 94.71% of the capacitance after 12,000 cycles. The supercapacitor consisted of the O-Cu-2h as the positive electrode and activated carbon as the negative electrode has an energy density of 24.20 Wh kg-1 and power density of 0.65 kW kg-1. The potential of using the electrode as oxygen evolution reaction catalysts is also investigated. The overpotential of O-Cu-2h at 10 mA cm-2 is 394 mV; however, the long-term stability still needs further improvement.
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The purpose of the current study was to define the role of MAX interactor 1 (Mxi1) in the pathogenesis of lung cancer and its underlying molecular mechanism. Bioinformatics analysis was performed to identify important regulatory pathway related to lung cancer. Dual luciferase reporter and ChIP assays were adopted to validate the interaction among Mxi1, miR-300 and KLF9. Loss- and gain-of-function studies were conducted to determine the roles of Mxi1, miR-300, and KLF9 in cell proliferation, migration, and invasion in vitro and their effects on myeloid-derived suppressor cell (MDSC) recruitment in vivo. Mxi1 was poorly expressed in lung cancer tissues and cells and its poor expression was associated with poor prognosis. Mxi1 inhibited miR-300 by suppressing its transcription. miR-300 suppressed the expression of KLF9, and KLF9 negatively regulated GADD34 expression in lung cancer cells. Mxi1 or KLF9 elevation or miR-300 repression inhibited lung cancer cell proliferation, as evidenced by reduced Ki67 and PCNA expression, and lowered invasion and migration. In vivo findings revealed that silencing KLF9 induced tumor growth by enhancing MDSC-mediated immunosuppression through upregulation of GADD34. Collectively, these findings suggest that Mxi1 can inhibit lung cancer progression by regulating the miR-300/KLF9 axis and GADD34-mediated immunosuppression.
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Neoplasias Pulmonares , MicroARNs , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Neoplasias Pulmonares/patología , MicroARNs/genética , MicroARNs/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
A number of C- and S-shaped perylene diimide (PDI) heterohelicenes with high dipole moments were synthesized from simple perylene tetrabutylester (PTE). Taking advantage of the weak coordination ability of the sterically crowded peri ester groups in PTE, efficient Rh(III)-catalyzed 2,8- and 2,11-bisiodinations of the perylene core were realized. The 2,8- and 2,11-diiodinated PTEs and PDIs represent key synthons for further ortho-π-extensions. In contrast to most helical π-skeletons that feature loose molecular packings, enantiomerically pure C-shaped PDI azahelicenes adopt unique spiral-stair-like π-stacking superstructures.
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The coordinative pliancy of the phosphonate functional group means that metal-phosphonate materials often self-assemble as well-packed structures with minimal porosity, as efficient inter-ligand packing is enabled. Here, we report a multistep synthesis of a novel aryl-phosphonate linker with an orthogonalized ligand core, 1,3,5-tris(4'-phosphonophenyl)-2,4,6-trimethylbenzene (H6 L2) designed to form more open structures. A series of crystalline metal-phosphonate frameworks (CALF-35 to -39) have been assembled by coordinating to divalent metals (Ba, Sr, Ca, Mg, Zn). H6 L2 is unable to pack efficiently and, as a consequence, yields several distinct microporous structures. The resulting structures are discussed in detail, with a focus on the solid-state packing of the sterically rigidified linker. Combined with larger cations (Sr, and Ba), H6 L2 packs in a parallel-offset manner, yielding isomorphous and microporous metal-organic frameworks (CALF-35 (Sr), and (Ba)). When coordinated to smaller metals (Ca, Mg, Zn), H6 L2 forms four new structures. Two Ca MOFs of different stoichiometry, (CALF-36 and 37) and a Mg MOF CALF-38 show narrow pores and have high selectivities for CO2 over N2 and CH4 . Finally, in CALF-39 (Zn), H6 L2 linkers pack in a herringbone fashion, resulting in a material with 10.9×10.1â Å2 square channels. The stability of all structures was tested, and the most porous structure, CALF-39 (Zn), was found to retain its structure and gas adsorption after immersion in water over pHâ 3-11.
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Estructuras Metalorgánicas , Organofosfonatos , Ligandos , Estructuras Metalorgánicas/química , Metales/química , PorosidadRESUMEN
Bacterial cellulose (BC) is an abundant biopolymer with a wide range of potential industrial applications. However, the industrial application of BC has been hampered by inefficient production. This study aims to investigate the influence of a spontaneous mutation that results in decreased cellulose production by a Komagataeibacter xylinus strain. The yields of cellulose are significantly different under different culture conditions, which imply that the shearing force is responsible for the selection of spontaneous mutants. Fermenter culture conditions under shake-flask culture conditions are further simulated. The shearing force activates the conversion of microbial cells to Cel- mutants, and the accumulation of water-soluble exopolysaccharides is observed. The Cel+ cells under agitated culture are not easily converted into Cel- mutants upon the addition of water-soluble exopolysaccharides synthesized by K. xylinus and a viscous polysaccharide, such as xanthan gum. The conversion ratio of Cel+ cells to Cel- mutants is strongly related to the shearing force and viscosity of the fermentation broth. The synthetic pathways of bacterial cellulose and water-soluble polysaccharides are independent of each other at the genetic level. However, a substrate competitive relationship between these two polysaccharides is found, which is significant in terms of the optimization of cellulose production in commercial processes.
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Celulosa , Gluconacetobacter xylinus , Bacterias/metabolismo , Biopolímeros , Fermentación , Gluconacetobacter xylinus/genética , Gluconacetobacter xylinus/metabolismo , AguaRESUMEN
Photocatalytic technology has been considered as an effective way for pollutants removal. Considering that the nature of the photodegradation of pollutants is the free radical reaction on the surface of the catalyst, promoting the generation of free radicals is a direct and effective way to facilitate the mineralization of pollutants. Unfortunately, the shortcomings strongly limit its photocatalytic activity such as insufficient sunlight utilization, small catalytic surface and rapid recombination of charge. Here, a heterostructure of defect-rich TiO2 nanoparticles anchored in g-C3N4 was fabricated by a synchronous compound process. This heterostructure (4TiO2/g-C3N4) exhibits an enhanced visible light absorption due to its narrow band gap energy of 2.27 eV. Therefore, it possesses an outstanding photocatalytic activity for the degradation of phenol (1.63 × 102 µmol g-1 h-1), p-nitrophenol (1.15 × 102 µmol g-1 h-1), o-cresol (1.43 × 102 µmol g-1 h-1) and p-cresol (1.45 × 102 µmol g-1 h-1). The calculated quantum yields of 4TiO2/CN for pollutants degradation are 1.29 × 10-6 for phenol, 9.10 × 10-7 for p-nitrophenol, 1.14 × 10-6 for o-cresol and 1.15 × 10-6 for p-cresol, respectively. By utilizing the periodic topology of MOFs, this work provides an improved approach for constructing TiO2/g-C3N4 heterojunctions with enhanced degradation of robust organic pollutants.
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Titanio , Aguas Residuales , Luz , FenolesRESUMEN
Metal-organic frameworks (MOFs) as solid sorbents for carbon dioxide (CO2) capture face the challenge of merging efficient capture with economical regeneration in a durable, scalable material. Zinc-based Calgary Framework 20 (CALF-20) physisorbs CO2 with high capacity but is also selective over water. Competitive separations on structured CALF-20 show not just preferential CO2 physisorption below 40% relative humidity but also suppression of water sorption by CO2, which was corroborated by computational modeling. CALF-20 has a low enthalpic regeneration penalty and shows durability to steam (>450,000 cycles) and wet acid gases. It can be prepared in one step, formed as composite materials, and its synthesis can be scaled to multikilogram batches.
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A stereoselective, copper-catalyzed, arene C(sp2)-H functionalization/Michael-type annulation reaction involving α-diazocarbonyl compounds has been developed. The method features low catalyst loadings, high yields, and excellent regio and stereoselectivity, in the synthesis of various heteroaromatic frameworks by employing indoles as the arene partner.
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Indolyl α-diazocarbonyl compounds have proven to be effective starting materials for the construction of various 2,3-ring fused indole frameworks. Activation of the diazo functional group under metal catalysis generates a spiro-cyclic indolenine-type intermediate which rearranges to provide two distinct carbazoles upon oxidation. The current study investigates the effects of the catalyst as well as the substituents on the migratory group involved in controlling the selectivity of the rearrangement.