RESUMO
Recently, facilely designable metal-organic frameworks have gained attention in the construction of photothermal conversion materials. Nonetheless, most of the previously reported photothermal conversion metal-organic frameworks exhibit limited light absorption capabilities. In this work, a distinctive metal-organic framework with heterogeneous periodic alternate spatial arrangements of metal-oxygen clusters and perylene-based derivative molecules was prepared by in situ synthesis. The building blocks in this inimitable structure behave as both electron donors and electron acceptors, giving rise to the significant inherent charge transfer in this crystalline material, resulting in a narrow band gap with excellent panchromatic absorption, with the ground state being the charge transfer state. Moreover, it can retain excellent air-, photo-, and water-stability in the solid state. The excellent stability and broad light absorption characteristics enable the effective realization of near-infrared (NIR) photothermal conversion, including infrequent NIR-II photothermal conversion, in this perylene-based metal-organic framework.
RESUMO
By harnessing the power of coordination self-assembly, crystalline materials can act as carriers for photoacids. Unlike their solution-based counterparts, these photoacids are capable of altering the properties of the crystalline material under light and can even generate proton transfer in a solid-state environment. Due to the photoinduced proton transfer and charge transfer processes within this functional material, this crystal exhibits powerful absorption spanning the visible to near-infrared spectrum upon light irradiation. This feature enables reproducible, significant chromatic variation, near-infrared photothermal conversion, and photocontrollable conductivity for this photoresponsive material. The findings suggest that the synthesis of pyranine photoacid-based crystalline materials via coordination self-assembly can not only enhance light-harvesting efficiency but also enable excited-state proton transfer processes within solid crystalline materials, thereby maintaining and even improving the properties of photoacids.
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As a common harmful pollutant, cadmium (Cd) can easily enter the human body through the food chain, posing a major threat to human health. Gut microbiota play a key role in Cd absorption. Docosahexaenoic acid (DHA) is thought to have a potential role in the treatment of Cd poisoning. This study investigated the therapeutic effect and mechanism of DHA in Cd-exposed mice from the perspective of the gut microbiota. The results showed that DHA significantly increased the Cd content in feces and decreased the Cd accumulation in the organs of mice. The gut microbiota results showed that DHA significantly restored the abundance of Parabacteroides in the gut microbiota of Cd-exposed mice. Parabacteroides distasonis (P. distasonis), a representative strain of the Parabacteroides, also showed Cd- and toxicity-reduction capabilities. P. distasonis significantly restored the gut damage caused by Cd exposure. At the same time, P. distasonis reduced the Cd content in the liver, spleen, lung, kidneys, gut, and blood to varying degrees and significantly increased the Cd content in feces. The succinic acid produced by P. distasonis plays an important role in promoting Cd excretion in Cd-exposed mice. Therefore, these results suggest that P. distasonis may have a potential role in DHA-mediated Cd excretion in Cd-exposed mice.
Assuntos
Líquidos Corporais , Microbioma Gastrointestinal , Humanos , Animais , Camundongos , Cádmio/toxicidade , Ácidos Docosa-Hexaenoicos/farmacologia , FezesRESUMO
Stimuli-responsive functional materials, especially the light stimulation color change and tunable fluorescent materials, have received considerable attention because of their broad applications in smart materials. Herein, a series of lanthanide-based [Ln = Nd(III) (1), Sm(III) (2), Eu(III) (3), Gd(III) (4), Tb(III) (5), Yb(III) (6), and Lu(III) (7)] crystalline complexes were attained by simply adding the aqueous lanthanide nitrate solution to the water-soluble naphthalenediimide derivative. The obtained lanthanide-based crystalline materials not only show significant photochromism but also possess reactive organic radicals under ambient conditions. Intriguingly, photoswitchable near-infrared (NIR) fluorescence was realized in the crystalline complex 1. The structures of these crystalline materials were systematically studied to clarify the weak interaction-assisted charge-transfer process. The underlying multiple-interaction-assisted supramolecular self-assembly, the radical-doped nature, and the corresponding photochromic mechanism were thoroughly unearthed by single-crystal X-ray diffraction, in situ solid-state UV-vis diffuse reflectance, and electron paramagnetic resonance spectrometric analysis.
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Room-temperature phosphorescence (RTP) was realized for the first time in a polyoxometalate-based charge-transfer (CT) hybrid material bearing polyoxometalates (POMs) as electron-donors (D) and rigid naphthalene diimides (NDIs) as electron-acceptors (A), meanwhile, this hybrid material displayed photochromism as well. The significant D-A anion-π interaction induced an additional through-space charge-transfer pathway. The resulting suitable D-A CT states can efficiently bridge the relatively large energy gap between the NDI-localized 1 π-π* and 3 π-π* states and thus trigger the ligand-localized phosphorescence (3 π-π*).
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Two efficient blue thermally activated delayed fluorescence compounds, B-oCz and B-oTC, composed of ortho-donor (D)-acceptor (A) arrangement were designed and synthesized. The significant intramolecular D-A interactions induce a combined charge transfer pathway and thus achieve small ΔEST and high efficiencies. The concentration quenching can be effectively inhibited in films of these compounds. The blue non-doped organic light emitting diodes (OLEDs) based on B-oTC prepared from solution processes shows record-high external quantum efficiency (EQE) of 19.1 %.
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Two mononuclear cuprous complexes [Cu(PNNA)(POP)]BF4 (1) and [Cu(PNNA)(Xantphos)]BF4 (2) (PNNA = 9,9-dimethyl-10-(6-(3-phenyl-1H-pyrazol-1-yl)pyridin-3-yl)-9,10-dihydroacridine, POP = bis[2-(dipenylphosphino)phenyl]ether, Xantphos =4,5-bis(diphenylphosphino)-9,9-dimethylxanthene), with intense bluish-green luminescence based on a new diimine ligand were designed and synthesized. Their structural, electrochemical, and photophysical properties were characterized by single-crystal X-ray analysis, cyclic voltammetry, temperature dependence of spectroscopy, time-dependent emission spectroscopy, etc. The complexes exhibit high photoluminescence quantum yields in doped films (up to 74.6%) at room temperature. Thermally activated delayed fluorescence based on intraligand charge transfer was observed by grafting a strong electron-donor moiety, 9,9-dimethylacridan, on the diimine ligand, which is supported by the density functional theory calculations on two complexes. Highly efficient solution-processed OLEDs based on these two complexes were fabricated, among which the electroluminescent device using 2 as dopant shows a peak external quantum efficiency of 7.42%, a peak current efficiency of 20.24 cd/A, and a maximum brightness of 5579 cd/m(2).
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An effective strategy to synthesize multifunctional materials is the incorporation of functional organic moieties and metal oxide clusters via self-assembly. A rare multifunctional radical-doped zinc-based host-guest crystalline material was synthesized with a fast-responsive reversible ultraviolet visible light photochromism, photocontrolled tunable luminescence, and highly selective photocatalytic oxidation of benzylic alcohols as a result of blending of distinctively different functional components, naphthalenediimide tectons, and polyoxometalates (POMs). It is highly unique to link π-electron-deficient organic tectons and POMs by unusual POMs anion-π interactions, which are not only conducive to keeping the independence of each component but also effectively promoting the charge transfer or exchange among the components to realize the fast-responsive photochromism, photocontrolled tunable luminescence, and photocatalytic activity.
RESUMO
The title compound, [Cu8(C15H10N3O3S)4Cl4(C3H7NO)2]·2C3H7NO, consisting of eight Cu(II) cations, four trianionic 1-(2-oxidobenzoyl)-2-(2-oxo-2-phenylethanethioyl)hydrazine-1,2-diide ligands, four chloride ligands and two coordinated and two solvent dimethylformamide molecules, crystallizes with the octanuclear molecule located on an inversion centre. The two halves of the molecule are connected by two bridging Cl atoms. This is the first example of an octanuclear complex based on a thiosemicarbazone-derived ligand.
Assuntos
Complexos de Coordenação/química , Tiossemicarbazonas/química , Cloretos , Cristalografia por Raios X , Dimetilformamida , Ligação de Hidrogênio , Ligantes , Conformação Molecular , Estrutura MolecularRESUMO
In the title complex, [Cu(C13H10N3O)2] n , the copper(II) cation is located on a crystallographic inversion centre and adopts an elongated octa-hedral coordination geometry with the equatorial plane provided by trans-arranged bis-N,O-chelating acyl-hydrazine groups from two ligands and the apices by the N atoms of two pyridine rings belonging to symmetry-related ligands. The ligand adopts a Z conformation about the C=N double bond. The dihedral angle between the pyridine and phenyl rings is 2.99â (13)°. An intra-ligand C-Hâ¯N hydrogen bond is observed. In the crystal, each ligand bridges two adjacent metal ions, forming a (4,4) grid layered structure. π-π stacking inter-actions [centroid-centroid distances in the range 3.569â (4)-3.584â (9)â Å] involving rings of adjacent layers result in the formation of a three-dimensional supra-molecular network.
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Antibiotics, being critical antimicrobial agents, have been widely used for treating bacterial infections. However, prolonged use of antibiotics can induce drug resistance resulting in "superbug" that threatens human health. Therefore, developing antibiotic-free materials with intrinsic antibacterial properties is the key to the "superbug" challenge. In this study, two highly efficient metal-organic frameworks (MOFs) were successfully assembled through synergistic use of the antibacterial properties of reactive organic radicals and silver (Ag) cations. These hybrid Ag-based materials possessed radical-doped characteristics, continuously releasing Ag+, which significantly inhibited the growth of four common Gram-negative and Gram-positive human pathogens (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus), and particularly two multi-drug-resistance bacteria (MRSA and MDR-PA). Furthermore, in vivo assays indicated that the synergistic antibacterial effect of these compounds could significantly accelerate the healing rate of infected wounds in mice. Blood biochemistry and histological analyses of main organs in treated mice also exhibited negligible cytotoxicity. This study unveiled the promising potential of Ag-MOFs for anti-infective therapies and future clinical applications.
Assuntos
Nanopartículas Metálicas , Estruturas Metalorgânicas , Infecções Estafilocócicas , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Escherichia coli , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Prata/química , Prata/farmacologia , Staphylococcus aureusRESUMO
In the present work, we have introduced a series of stable radical-doped coordination compounds composed of donor-acceptor structures and shown to produce organic radicals in situ as a result of unconventional lone pair-π interactions in ambient conditions. Inconspicuous lone pair-π and C-Hπ interactions were shown to play a key role in self-assembly as well as the charge transfer process, resulting in a long-lived charge-separated state able to generate organic radicals. The resultant species displayed broad-spectrum antimicrobial activity, including against multi-drug-resistant bacteria. This study unveiled the promise of reactive organic radical-doped materials as a new platform for developing antimicrobial agents that can overcome antibiotic resistance.
Assuntos
Antibacterianos/química , Radicais Livres/química , Estruturas Metalorgânicas/química , Naftalimidas/química , Antibacterianos/farmacologia , Bacillus subtilis , Farmacorresistência Bacteriana Múltipla , Escherichia coli , Estruturas Metalorgânicas/farmacologia , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Semicondutores , Staphylococcus aureus , Relação Estrutura-AtividadeRESUMO
Two emissive copper(i) halide complexes (PNNP)Cu2Br2 (1) and (PNNP)Cu2I2 (2), which are constructed from butterfly-shaped dinuclear Cu2X2 cores and a new tetradentate ligand (PNNP = 1,3-bis(1-(2-(diphenylphosphanyl)phenyl)-1H-pyrazol-3-yl)benzene), were synthesized and characterized. These chelates exhibit bright green (λmax = 517 nm, 1) and bluish-green (λmax = 492 nm, 2) photoluminescence in the solid state with quantum yields of 42% (1) and 58% (2), and lifetimes of 13 µs (1) and 8.8 µs (2) at room temperature. Computational density functional theory/time-dependent density functional theory (DFT/TDDFT) calculations were performed to elucidate the nature of their electronic transitions and to predict their detailed photophysical properties. The results of DFT/TDDFT calculations, combined with the temperature dependence of spectroscopic properties and emission decay behaviors, suggest that the emission in the solid state originates from the 1,3(MLCT + XLCT + ILCT) excited states, which are in thermal equilibrium with small energy differences of about 0.1 eV. A comparative study of the titled complexes reveals that the emissive-state characteristics and photophysical properties of these complexes are significantly affected by the ligand field strength and atomic number of the halogen atom, as well as by the percentage of the XLCT transition involved in the lowest excited states. Compared with its bromide counterpart (1), the iodide complex (2) shows a much higher phosphorescence quantum yield (0.94 vs. 0.50), a much shorter phosphorescence decay time (58 µs vs. 274 µs), a much larger phosphorescence rate constant (1.6 × 104 s-1vs. 1.8 × 103 s-1), and a larger phosphorescence contribution (25% vs. 8%) in room-temperature emission, due to the more efficient spin-orbit coupling (SOC).
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A trigonal propeller-shaped hybrid polyoxometalate (POM) (NH2Me2)3{[Nd(Mo4O13)(DMF)4]3(BTC)2}·8DMF (1; BTC = 1,3,5-benzenetricarboxylate) has been synthesized and structurally characterized. The planar {Mo4} segment is tailored from the precursor Lindqvist polyoxoanion [Mo6O19]2- firstly, and plays a key role in the reassembly of 1. Furthermore, the magnetic studies reveal that 1 shows single-molecule magnet (SMM) behavior.
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Utilizing metal-ligand binding as the driving force, a unique photochromic hydrogel cross-linked by metal ions and π-acidic naphthalene bisimide dyes was obtained by simply mixing a two-phase solution. The mechanism of the coordination-driven self-assembly is elucidated by the morphological, XRD, FT-IR, ESR, UV-Vis and TGA studies and the controlled experiments.
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Lone pair-π interaction-induced charge-transfer was successfully used for switching the conductance of a coordination network, through variation of the degree of charge transfer caused by external photostimulation. The underlying mechanism is attributed to the changes in efficient charge-carriers by photoinduced strong charge transfer, which was investigated by in situ UV-Vis absorption, ESR, and computational studies.
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The first visible-light-responsive photochromic polyoxometalate-templated lanthanide-organic framework (LOF) has been constructed from a carboxyphenyl-substituted naphthalenediimide (NDI) derivative, which displays an unusual four-fold interpenetration of an srs topological network, featuring a variety of anion-π interactions between polyoxoanions and π-acidic NDI moieties, and undergoes a rapid reversible photochromic transformation upon blue light irradiation.
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A novel structure of ferrocene derivative 1 was synthesized with cyanuric chloride and ferrocenemethanol as starting materials. The synthesized compound was fully characterized using 1H NMR, 13C NMR, MS and XRD. Subsequently, the in vitro anticancer effect against A549, HCT116 and MCF-7 cell lines was preliminarily evaluated by the MTT method. The result showed that this compound exhibits good cytotoxic effect on A549, HCT116 and MCF-7 cell lines.
Assuntos
Antineoplásicos/farmacologia , Compostos Ferrosos/farmacologia , Triazinas/farmacologia , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Cristalografia por Raios X , Compostos Ferrosos/síntese química , Compostos Ferrosos/química , Células HCT116 , Humanos , Células MCF-7 , Espectroscopia de Prótons por Ressonância Magnética , Triazinas/síntese química , Triazinas/químicaRESUMO
An unusual room-temperature light sensitivity was realized in a polyoxometalate-based hybrid material due to cooperative multicomponent molecular charge-transfer interactions taking place in this material, mainly among POMs, NDIs, and other molecules. The functional π-acidic NDI linkers and POM clusters in the discussed hybrid material were individually designed as photosensors and electron reservoirs. To propose a photo-induced charge-transfer mechanism, EPR, XPS, UV-Vis and computational studies were carried out, and indicated the presence of active charge-transfer interactions among several of the components.
RESUMO
The hydrothermal reactions of a mixture of (NH4)6Mo7O24·4H2O, Cu(Ac)2·H2O and 3-bpo ligands at different temperatures result in the isolation of two novel inorganic-organic hybrid materials containing different but related isopolymolybdate units, [Cu(3-bpo)(H2O)(Mo4O13)]·3H2O () and [Cu2(3-bpo)2(Mo6O20)] (). The {Mo4O13}n chains in and unprecedented [Mo6O20](4-) isopolyhexamolybdate anions in are linked by octahedral Cu(2+) ions into two-dimensional hybrid layers. Interestingly, 3-bpo ligands in both and are located on either side of these hybrid layers and serve as arched footbridges to link Cu(ii) ions in the layer via pyridyl N-donors, and at the same time connect these hybrid layers into 3D supramolecular frameworks via weak MoNoxadiazole bonds. Another important point for is that water clusters are filled in the 1D channels surrounded by isopolytetramolybdate units. In addition, dye adsorption and photocatalytic properties of and magnetic properties of have been investigated. The results indicated that complex is not only a good heterogeneous photocatalyst in the degradation of methyl orange (MO) and methylene blue (MB), but also has high absorption capacity of MB at room temperature and can selectively capture MB molecules from binary mixtures of MB/MO or MB/RhB. All MB molecules absorbed on can be completely released and photodegraded in the presence of adequate peroxide. The temperature dependence of magnetic susceptibility revealed that complex exhibits antiferromagnetic ordering at about 5 K, and a spin-flop transition was observed at about 5.8 T at 2 K, indicating metamagnetic-like behaviour from antiferromagnetic to ferromagnetic phases.