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1.
Fish Shellfish Immunol ; 149: 109551, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38599363

RESUMO

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.


Assuntos
Ração Animal , Bass , Dieta , Suplementos Nutricionais , Glycine max , Fígado , Pleurotus , Animais , Bass/imunologia , Bass/crescimento & desenvolvimento , Ração Animal/análise , Dieta/veterinária , Pleurotus/química , Glycine max/química , Fígado/imunologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Suplementos Nutricionais/análise , Intestinos/imunologia , Intestinos/efeitos dos fármacos , Fermentação , Imunidade Inata/efeitos dos fármacos , Distribuição Aleatória , Raízes de Plantas/química , Relação Dose-Resposta a Droga
2.
Chemistry ; 29(17): e202203835, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36581566

RESUMO

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 400-600 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 (530-900 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.

3.
Chemistry ; 28(31): e202200874, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35349770

RESUMO

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 10.9×10.1 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 pH 3-11.


Assuntos
Estruturas Metalorgânicas , Organofosfonatos , Ligantes , Estruturas Metalorgânicas/química , Metais/química , Porosidade
4.
J Biol Inorg Chem ; 25(5): 759-776, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32583226

RESUMO

The potential chemotherapeutic properties coupled to photochemical transitions make the family of fac-[Re(CO)3(N,N)X]0/+ (N,N = a bidentate diimine such as 2,2'-bipyridine (bpy); X = halide, H2O, pyridine derivatives, PR3, etc.) complexes of special interest. We have investigated reactions of the aqua complex fac-[Re(CO)3(bpy)(H2O)](CF3SO3) (1) with potential anticancer activity with the amino acid L-cysteine (H2Cys), and its derivative N-acetyl-L-cysteine (H2NAC), as well as the tripeptide glutathione (H3A), under physiological conditions (pH 7.4, 37 °C), to model the interaction of 1 with thiol-containing proteins and enzymes, and the impact of such coordination on its photophysical properties and cytotoxicity. We report the syntheses and characterization of fac-[Re(CO)3(bpy)(HCys)]·0.5H2O (2), Na(fac-[Re(CO)3(bpy)(NAC)]) (3), and Na(fac-[Re(CO)3(bpy)(HA)])·H2O (4) using extended X-ray absorption spectroscopy, IR and NMR spectroscopy, electrospray ionization spectrometry, as well as the crystal structure of {fac-[Re(CO)3(bpy)(HCys)]}4·9H2O (2 + 1.75 H2O). The emission spectrum of 1 displays a variance in Stokes shift upon coordination of L-cysteine and N-acetyl-L-cysteine. Laser excitation at λ = 355 nm of methanol solutions of 1-3 was followed by measuring their ability to produce singlet oxygen (1O2) using direct detection methods. The cytotoxicity of 1 and its cysteine-bound complex 2 was assessed using the MDA-MB-231 breast cancer cell line, showing that the replacement of the aqua ligand on 1 with L-cysteine significantly reduced the cytotoxicity of the Re(I) tricarbonyl complex. Probing the cellular localization of 1 and 2 using X-ray fluorescence microscopy revealed an accumulation of 1 in the nuclear and/or perinuclear region, whereas the accumulation of 2 was considerably reduced, potentially explaining its reduced cytotoxicity. Replacing the aqua ligand with cysteine in the antitumor active fac-[Re(CO)3(bpy)(H2O)](CF3SO3) complex significantly reduced its cellular accumulation and cytotoxicity against the MDA-MB-213 breast cancer cell line, shifted its maximum emission to considerably higher energies, and decreased its fluorescence quantum yield.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Cisteína/farmacologia , Rênio/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Monóxido de Carbono/análise , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Cisteína/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Conformação Molecular , Rênio/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
5.
J Am Chem Soc ; 141(2): 1045-1053, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30582892

RESUMO

Overcoming the brittleness of metal-organic frameworks (MOFs) is a challenge for industrial applications. To increase the mechanical strength, MOFs have been blended with polymers to form composites. However, this also brings challenges, such as integration and integrity of MOF in the composite, which can hamper the selectivity of gas separations. In this report, an "all MOF" material with mechanical flexibility has been prepared by covalent cross-linking of metal-organic polyhedra (MOPs). The ubiquitous Cu24 isophthalate MOP has been decorated with a long alkyl chain having terminal alkene functionalities so that MOPs can be cross-linked via olefin metathesis using Grubbs second generation catalyst. Different degrees of cross-linked MOP materials have been obtained by varying the amount of catalyst in the reaction. Rheology of these structures with varying number of cross-links was performed to assess the cross-link density and its homogeneity throughout the sample. The mechanical properties were further investigated by the nanoindentation method, which showed increasing hardness with higher cross-link density. Thus, this strategy of cross-linking MOPs with covalent flexible units allows us to create MOFs of increasing mechanical strength while retaining the MOP cavities.

6.
Chemistry ; 25(17): 4305-4308, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30723967

RESUMO

Isolable cationic PtII and PtIV alkylidenes, proposed intermediates in catalytic organic transformations, are reported. The bonding in these species was probed by experimental, structural, spectroscopic, electrochemical and computational methods, providing direct evidence for π-bonding, the often-theorized relativistic stabilization of these species, and the influence of oxidation state.

7.
Inorg Chem ; 58(15): 9874-9881, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31335137

RESUMO

Metal-organic polyhedra (MOPs) are increasingly studied as host-guest capsules, linked into networks, or incorporated into composite materials. As such, understanding the decomposition of MOP structures is of fundamental importance. The degradation of the ubiquitous copper(II) MOP Cu24[5-(hydroxy)isophthalate]24 (1) is studied in liquid water. At different intervals of water exposure, powder X-ray diffraction (PXRD) is performed and stepwise conversion of the MOP into three different coordination polymers is observed. First, the formation of a 2D coordination polymer, 2, is observed, which upon further exposure gives a 1D coordination polymer, 3, and finally a trinuclear copper(II) complex, 4. Compound 2 is characterized by PXRD owing to its transient nature, while 3 and 4 are characterized crystallographically. The final structure, 4, contains copper(II) trimers, and so its magnetic behavior is also investigated.

8.
Inorg Chem ; 58(9): 6246-6256, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-30997801

RESUMO

Three Co(II) metal-organic frameworks, namely, {[Co2(L)2(OBA)2(H2O)4]· xG} n (1), {[Co(L)0.5(OBA)]· xG} n (2), and {[Co2(L)2(OBA)2(H2O)]·DMA· xG} n (3) [where L = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene, H2OBA = 4,4'-oxybisbenzoic acid, DMF = dimethylformamide, DMA = dimethylacetamide, and G denotes disordered guest molecules], have been synthesized under diverse reaction conditions through self-assembly of a bent dicarboxylate and a linear spacer with a Co(II) ion. While 1 is crystallized at room temperature in DMF to form a 2D layer structure, 2 is formed by the assembly of similar components under solvothermal conditions with a 3D network structure. On the other hand, changing the solvent to DMA, 3 could be crystallized at room temperature with a 3D architecture. Out of the three, activated sample 2 was found to be permanently microporous in nature, with a BET surface area of 385 m2/g, and exhibited moderately high uptake capacity for C2H2 and CO2 while taking up much less CH4 and N2 at ambient conditions. As a result, high ideal adsorbed solution theory (IAST) separation selectivities are obtained for CO2/N2 (15:85), CO2/CH4 (50:50), and C2H2/CH4 (50:50) gas mixtures, making 2 a potential candidate for those important gas separations at ambient conditions. Moreover, the magnetic properties of 1-3 were studied. 1 and 2 show antiferromagnetic interaction between the Co(II) centers, whereas 3 displays ferromagnetic behavior arising from a counter-complementary effect between two types of links among Co(II) centers in 3.

9.
J Am Chem Soc ; 139(21): 7176-7179, 2017 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-28510427

RESUMO

A sulfonated indium (In) metal organic framework (MOF) is reported with an anionic layered structure incorporating hydrogen-bonded dimethylammonium cations and water molecules. The MOF becomes amorphous in >60% relative humidity; however, impedance analysis of pelletized powders revealed a proton conduction value of over 10-3 S cm-1 at 25 °C and 40% RH, a very high proton conduction value for low humidity and moderate temperature. Given the modest humidity stability of the MOF, triaxial impedance analyses on a single crystal was performed and confirmed bulk proton conductivity over 10-3 S cm-1 along two axes corroborating the data from the pellet.

10.
Chemistry ; 22(34): 12088-94, 2016 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-27383009

RESUMO

A series of highly connected metal-organic frameworks (MOFs), [Co8 (O)(OH)4 (H2 O)4 (ina)8 ](NO3 )2 ⋅2 C2 H5 OH⋅4 H2 O (1), [Co8 (O)(OH)4 (H2 O)4 (pba)8 ](NO3 )2 ⋅8 C2 H5 OH⋅28 H2 O (2), and [Co8 (O)(OH)4 (H2 O)4 (pbba)8 ](NO3 )2 ⋅guest (3), in which ina=isonicotinate, pba=4-pyridylbenzoate, and pbba=4-(pyridine-4-yl)phenylbenzoate, is reported. These MOFs contain a new secondary building unit (SBU), with a square Co4 (µ4 -O) central unit having the rare µ4 -O(2-) motif, which is decorated by the other four peripheral cobalt atoms through µ3 -OH in a windmill-like shape. This SBU holds 16 divergent connecting organic ligands, pyridyl-carboxylates, to form three different frameworks. The high porosity of desolvated 2 is shown by the efficient gas absorption of N2 , CO2 , CH4 , and H2 . In addition, 1 and 2 exhibit unusual canted antiferromagnetic behavior with spin-glass-like relaxation, with blocking temperatures that are fairly high, 20 K (1) and 10 K (2), for cobalt materials. The relationship between the metal clusters and linkers has been studied, in which the size and rotational degrees of freedom of the ligands are found to control the topology, gas sorption, and magnetic properties.

11.
Inorg Chem ; 54(4): 1185-7, 2015 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-25646642

RESUMO

Phosphonate monoesters are atypical linkers for metal-organic frameworks, but they offer potentially added versatility. In this work, a bulky isopropyl ester is used to direct the topology of a copper(II) network from a dense to an open framework, CALF-30. CALF-30 shows no adsorption of N2 or CH4 however, using CO2 sorption, CALF-30 was found to have a Langmuir surface area of over 300 m(2)/g and to be stable to conditions of 90% relative humidity at 353 K owing to kinetic shielding of the framework by the phosphonate ester.

12.
Dalton Trans ; 53(4): 1862-1869, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38179611

RESUMO

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 RuC 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.

13.
J Inorg Biochem ; 240: 112092, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36549168

RESUMO

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).


Assuntos
Antineoplásicos , Rênio , Selênio , Humanos , Rênio/química , Metimazol , Células HEK293 , Antineoplásicos/farmacologia
14.
Inorg Chem ; 51(17): 9423-30, 2012 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-22905740

RESUMO

A two-dimensional (2D) square-grid type porous coordination polymer [Fe(bdpt)(2)]·guest (1·g, Hbdpt = 3-(5-bromo-2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole) with isolated small cavities was designed and constructed as a spin-crossover (SCO) material based on octahedral Fe(II)N(6) units and an all-nitrogen ligand. Three guest-inclusion forms were successfully prepared for 1·g (1·EtOH for g = ethanol, 1·MeOH for g = methanol, 1 for g = Null), in which the guest molecules interact with the framework as hydrogen-bonding donors. Magnetic susceptibility measurements showed that 1·g exhibited two-step SCO behavior with different transition temperatures (1·EtOH < 1·MeOH < 1) and hysteresis widths (1·EtOH > 1·MeOH > 1 ≈ 0). Such guest modulation of two-step spin crossover temperature and hysteresis without changing two-step state in a porous coordination framework is unprecedented. X-ray single-crystal structural analyses revealed that all two-step SCO processes were accompanied with interesting symmetry-breaking phase transitions from space group of P2(1)/n for all high-spin Fe(II), to P1 for ordered half high-spin and half low-spin Fe(II), and back to P2(1)/n for all low-spin Fe(II) again by lowering temperature. The different SCO behaviors of 1·g were elucidated by the steric mechanism and guest-host hydrogen-bonding interactions. The SCO behavior of 1·g can be also controlled by external physical pressure.

15.
Inorg Chem ; 50(6): 2321-8, 2011 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-21341729

RESUMO

A microporous coordination polymer, namely, [Co(3)(ina)(4)(OH)(C(2)H(5)OH)(3)](NO(3))·C(2)H(5)OH·(H(2)O)(3) (1, or MCF-38, ina = isonicotinate), with 8-connected {Co(3)(OH)} clusters as the structural secondary building units, has been solvothermally synthesized. The hydroxo-centered Co(II) cluster involves multiple active metal sites. The interesting apical ligand substitutions have been directly observed, and the corresponding products of [Co(3)(ina)(4)(OH)(G)(x)(H(2)O)(n)](NO(3))·G·(H(2)O)(m) (1 ⊃ PrOH, G = PrOH, x = 2, n = 1, m = 3; 1 ⊃ BuOH, G = BuOH, x = 2, n = 1, m = 1, and 1 ⊃ MeOH, G = MeOH, x = 3, n = 0, m = 7) have also been obtained by solvothermal syntheses or crystal-to-crystal transformations. High-pressure H(2) adsorption measurement at 77 K reveals that activated 1 can absorb 2.2 wt % H(2) at 5 bar. The relative H(2) absorption at low pressure (86% of the storage capacity at 1 bar) is higher than the corresponding values reported for some typical porous coordination polymers. The magnetic studies of 1 show a dominant antiferromagnetic coupling between Co(II) ions of intra- and inter-cluster.


Assuntos
Cobalto/química , Hidrogênio/química , Magnetismo , Compostos Organometálicos/química , Polímeros/química , Adsorção , Domínio Catalítico , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Compostos Organometálicos/síntese química , Polímeros/síntese química , Porosidade
16.
Org Lett ; 23(14): 5559-5564, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34197126

RESUMO

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.

17.
Chem Commun (Camb) ; 57(81): 10556-10559, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34557880

RESUMO

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.

18.
Org Lett ; 23(14): 5461-5465, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34228471

RESUMO

Work on the synthesis of [2.2]paracyclophane/9-alkylfluorene hybrids led to the discovery of the rearrangement of cyclopentadienone 7 to cyclophane 6. A DFT computational study revealed that this formal 1,3-alkyl shift occurs in two steps, but requires the participation of a solvent molecule (ethanol). The rearrangement could be avoided by generating 7 under mild conditions and using benzynes as dienophiles to afford the targeted cyclophanes 14 and 16, the latter of which exhibits dual fluorescence emission.

19.
Science ; 374(6574): 1464-1469, 2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34914501

RESUMO

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.

20.
J Am Chem Soc ; 132(19): 6654-6, 2010 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-20420376

RESUMO

Gas sorption experiments and grand canonical Monte Carlo simulations for two isostructural microporous metal azolate frameworks show that even partially exposed uncoordinated nitrogens can effectively increase gas binding affinity and overcome the pore size confinement effect.


Assuntos
Gases/química , Polímeros/química , Adsorção , Modelos Moleculares , Conformação Molecular , Método de Monte Carlo , Compostos Organometálicos/química , Porosidade , Triazóis/química
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