Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
FASEB J ; 38(3): e23455, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38308636

RESUMO

Recent evidence suggests the anti-inflammatory effect of carrageenan oligosaccharides (COS). The effects of COS on intestinal injury induced by 0.6% sodium dodecyl sulfate (SDS) and the molecular mechanisms involved were investigated in this study. 0.625, 1.25, and 2.5 mg/mL COS in diet had no toxic effect in flies, and they could all prolong SDS-treated female flies' survival rate. 1.25 mg/mL COS prevented the development of inflammation by improving the intestinal barrier integrity and maintaining the intestinal morphology stability, inhibited the proliferation of intestine stem cells (ISCs), and the production of lysosomes induced by SDS, accompanied by a decrease in the expression of autophagy-related genes. Moreover, COS decreased the active oxygen species (ROS) content in gut and increased the antioxidant activity in SDS-induced female flies, while COS still played a role in increasing survival rate and decreasing intestinal leakage in CncC-RNAi flies. The improvement of anti-inflammation capacity may be associated with the regulation of intestinal microflora with COS supplementation for Drosophila melanogaster. COS changed the gut microbiota composition, and COS had no effect on germ-free (GF) flies. It is highlighted that COS could not work in Relish-RNAi flies, indicating relish is required for COS to perform beneficial effects. These results provide insights into the study of gut microbiota interacting with COS to modulate intestinal inflammation in specific hosts.


Assuntos
Drosophila melanogaster , Microbioma Gastrointestinal , Animais , Feminino , Carragenina/farmacologia , Inflamação , Intestinos , Oligossacarídeos/farmacologia
2.
J Am Chem Soc ; 146(6): 4036-4044, 2024 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-38291728

RESUMO

As an important biomarker, ammonia exhibits a strong correlation with protein metabolism and specific organ dysfunction. Limited by the immobile instrumental structure, invasive and complicated procedures, and unsatisfactory online sensitivity and selectivity, current medical diagnosis fails to monitor this chemical in real time efficiently. Herein, we present the successful synthesis of a long-range epitaxial metal-organic framework on a millimeter domain-sized single-crystalline graphene substrate (LR-epi-MOF). With a perfect 30° epitaxial angle and a mere 2.8% coincidence site lattice mismatch between the MOF and graphene, this long-range-ordered epitaxial structure boosts the charge transfer from ammonia to the MOF and then to graphene, thereby promoting the overall charge delocalization and exhibiting extraordinary electrical global coupling properties. This unique characteristic imparts a remarkable sensitivity of 0.1 ppb toward ammonia. The sub-ppb detecting capability and high anti-interference ability enable continuous information recording of breath ammonia that is strongly correlated with the intriguing human lifestyle. Wearable electronics based on the LR-epi-MOF could accurately portray the active protein metabolism pattern in real time and provide personal assistance in health management.


Assuntos
Grafite , Estruturas Metalorgânicas , Humanos , Amônia , Grafite/química , Eletrônica
3.
Small ; : e2402314, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38708815

RESUMO

Topology serves as a blueprint for the construction of reticular structures such as metal-organic frameworks, especially for those based on building blocks with highly symmetrical shapes. However, it remains a challenge to predict the topology of the frameworks from less symmetrical units, because their corresponding vertex figures are largely deformed from the perfect geometries with no "default" net embedding. Furthermore, vertices involving flexible units may have multiple shape choices, and the competition among their designated topologies makes the structure prediction in large uncertainty. Herein, the deformation index is proposed to characterize the symmetry loss of the vertex figure by comparing it with its ideal geometry. The mathematical index is employed to predict the shapes of two in situ formed Co-based metalloligands (pseudo-tetrahedron and pseudo-square), which further dictate the framework topology (flu and scu) when they are joined with the [Zr6O8]-based cuboid units. The two frameworks with very similar constituents provide an ideal platform to investigate how the pore shapes and interconnectivity influence the gas separation. The net with cylindrical channels outperforms the other with discreate cages in C3H8/C2H6/CH4 separation, benefiting from the facile accessibility of its interaction sites to the guests imposed by the specific framework topology.

4.
Inorg Chem ; 63(23): 10585-10593, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38798023

RESUMO

Solid electrolytes with high ionic conductivity and satisfactory electrochemical stability are essential for the development of solid-state batteries. However, current strategies, including polymer (and polymer-based composite) electrolytes, still face challenges in meeting the bar set by real operations. We seek to improve the Li-ion conduction of the electrolytes by incorporating mesoporous metal-organic frameworks (MOFs) into the polymer matrix. Specifically, MOFs with pores larger than 3.0 nm are constructed by three-component reactions that involve the construction of both coordinative and dynamic imine linkages. The MOFs allow polymer penetration and amorphization and efficient lithium salt dissociation in the confined channels. Numerous metal sites and organic functionalities in the MOF backbone further assist the ion migration by providing strong interactions with the fluorinated polymer and the Li+. Remarkable ionic conductivity (0.95 mS cm-1) and a large lithium transference number (0.64) are achieved. Overall, the study fully utilizes both the MOF structural units with atomic precision and the encompassed space at the mesoscale for solid-state electrolyte development.

5.
J Am Chem Soc ; 145(48): 26169-26178, 2023 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-37988478

RESUMO

Imaging-guided chemodynamic therapy is widely considered a promising modality for personalized and precision cancer treatment. Combining both imaging and chemodynamic functions in one system conventionally relies on the hybrid materials approach. However, the heterogeneous, ill-defined, and dissociative/disintegrative nature of the composites tends to complicate their action proceedings in biological environments and thus makes the treatment imprecise and ineffective. Herein, a strategy to employ two kinds of inorganic units with different functions─reactive oxygen species generation and characteristic emission─has achieved two single-crystalline metal-organic frameworks (MOFs), demonstrating the competency of reticular chemistry in creating multifunctional materials with atomic precision. The multinary MOFs could not only catalyze the transformation from H2O2 to hydroxyl radicals by utilizing the redox-active Cu-based units but also emit characteristic tissue-penetrating near-infrared luminescence brought by the Yb4 clusters in the scaffolds. Dual functions of MOF nanoparticles are further evidenced by pronounced cell imaging signals, elevated intracellular reactive oxygen species levels, significant cell apoptosis, and reduced cell viabilities when they are taken up by the HeLa cells. In vivo NIR imaging is demonstrated after the MOF nanoparticles are further functionalized. The independent yet interconnected modules in the intact MOFs could operate concurrently at the same cellular site, achieving a high spatiotemporal consistency. Overall, our work suggests a new method to effectively accommodate both imaging and therapy functions in one well-defined material for precise treatment.


Assuntos
Estruturas Metalorgânicas , Nanopartículas , Neoplasias , Humanos , Estruturas Metalorgânicas/farmacologia , Estruturas Metalorgânicas/química , Células HeLa , Espécies Reativas de Oxigênio , Peróxido de Hidrogênio , Fototerapia , Nanopartículas/química , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Linhagem Celular Tumoral
6.
Small ; 19(32): e2303069, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37165759

RESUMO

Amination of aryl chlorides by metallaphotocatalysis is highly desired but remains practically challenging. Meanwhile, relying on soluble noble-metal photocatalysts suffers from resource scarcity and structural instability which limit their practical application. Here in, a highly crystalline acetylene-based hydrazone-linked covalent organic framewok-1 (AC-COF-1) is reported that enables metallaphotocatalytic amination of aryl chlorides. The non-planar effect of hydrazone linkage and weak interlayer attraction of acetylene bond are minimized by intralayer hydrogen-bonding. As a result, the COF shows not only improved crystallinity and porosity, but also enhanced optical and electronic properties compared to a COF analog without hydrogen-bonding. Notably, dual AC-COF-1/Ni system affords CN coupling products from broad aryl chloride substrates in excellent yields (up to 99%) and good functional tolerance. Furthermore, AC-COF-1 is recoverable and reusable for seven times photocatalysis cycles. This report demonstrates simple approach to tune the structure-activity relationship in COFs at molecular level.

7.
J Magn Reson Imaging ; 57(4): 1262-1274, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35924395

RESUMO

BACKGROUND: The relationship between resting cardiac indices and exercise capacity in older adults was still not well understood. New developments in cardiac magnetic resonance imaging (MRI) enable a much fuller assessment of cardiac characteristics. PURPOSE/HYPOTHESIS: To assess the association between exercise capacity and specific aspects of resting cardiac structure, function, and tissue. STUDY TYPE: Cross-sectional study. POPULATION: A total of 112 well-functioning older adults (mean age 69 years, 52 men). FIELD STRENGTH/SEQUENCE: All participants underwent 3.0 T MRI, using scan protocols including balanced steady-state free precession cine sequence, modified look-locker inversion recovery, and T2-prepared single-shot balanced steady-state free precession. ASSESSMENT: Demographic and geriatric characteristics were collected. Blood samples were assayed for lipid and glucose related biomarkers. All participants performed a symptom-limited cardiopulmonary exercise test to achieve peakVO2 . Cardiac MRI parameters were measured with semi-automatic software by S.Y., an 18-year experienced radiologist. STATISTICAL TESTS: Demographic, geriatric characteristics and MR measurements were compared among quartiles of peakVO2, with different methods according to the data type. Spearman's partial correlation and least absolute shrinkage selection operator regression were performed to select significant MR features associated with peakVO2 . Mediation effect analysis was conducted to test any indirect connection between age and peakVO2 . A two-sided P value of <0.05 was defined statistical significance. RESULTS: Epicardial fat volume, left atrial volume indexed to height, right ventricular end-systolic volume indexed to body surface area and global circumferential strain (GCS) were correlated with peakVO2 (regression coefficients were -0.040, -0.093, 0.127, and 0.408, respectively). Mediation analysis showed that the total effect of peakVO2 change was 43.6% from the change of age. The proportion of indirect effect from epicardial fat volume and GCS were 11.8% and 15.1% in total effect, respectively. DATA CONCLUSION: PeakVO2 was associated with epicardial fat volume, left atrial volume, right ventricular volume and GCS of left ventricle. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 5.


Assuntos
Tolerância ao Exercício , Imageamento por Ressonância Magnética , Masculino , Humanos , Idoso , Estudos Transversais , Ventrículos do Coração , Átrios do Coração , Imagem Cinética por Ressonância Magnética/métodos , Função Ventricular Esquerda , Volume Sistólico
8.
Angew Chem Int Ed Engl ; 62(6): e202217864, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36479801

RESUMO

In contrast to the vast Al-oxo molecular cluster chemistry, Al-based building units for metal-organic framework (MOF) construction are limited in structural diversity and complexity. Synthesis of single crystalline MOFs based on this "hard" metal is further complicated by the poor reversibility of the Al-organic coordination linkages. Here, a strategy to employ two kinds of linkages with distinct strength-strong Al-carboxylate linkage and weak Cu-pyrazol N linkage-gives FDM-91 (FDM=Fudan Materials) with gigantic Al24 -based units. After replacing the weak moieties with organic linkers post-synthetically, two new stable MOFs with exceptional water harvesting capacity (up to 0.53 g g-1 ) and outstanding cycling performance are developed. Linkage-selective dissociation of FDM-91 further leads to the isolation of the Al24 molecular clusters. The versatile chemistry performed here to reinforce or deconstruct MOFs provides a new way to make important extended and discrete structures.

9.
Genet Sel Evol ; 54(1): 62, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104777

RESUMO

BACKGROUND: The genetic mechanisms that underlie phenotypic differentiation in breeding animals have important implications in evolutionary biology and agriculture. However, the contribution of cis-regulatory variants to pig phenotypes is poorly understood. Therefore, our aim was to elucidate the molecular mechanisms by which non-coding variants cause phenotypic differences in pigs by combining evolutionary biology analyses and functional genomics. RESULTS: We obtained a high-resolution phased chromosome-scale reference genome with a contig N50 of 18.03 Mb for the Luchuan pig breed (a representative eastern breed) and profiled potential selective sweeps in eastern and western pigs by resequencing the genomes of 234 pigs. Multi-tissue transcriptome and chromatin accessibility analyses of these regions suggest that tissue-specific selection pressure is mediated by promoters and distal cis-regulatory elements. Promoter variants that are associated with increased expression of the lysozyme (LYZ) gene in the small intestine might enhance the immunity of the gastrointestinal tract and roughage tolerance in pigs. In skeletal muscle, an enhancer-modulating single-nucleotide polymorphism that is associated with up-regulation of the expression of the troponin C1, slow skeletal and cardiac type (TNNC1) gene might increase the proportion of slow muscle fibers and affect meat quality. CONCLUSIONS: Our work sheds light on the molecular mechanisms by which non-coding variants shape phenotypic differences in pigs and provides valuable resources and novel perspectives to dissect the role of gene regulatory evolution in animal domestication and breeding.


Assuntos
Genoma , Genômica , Animais , Evolução Molecular , Fenótipo , Análise de Sequência de DNA , Suínos/genética
10.
Arch Phys Med Rehabil ; 103(8): 1663-1675.e3, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35026150

RESUMO

OBJECTIVE: To investigate the available evidence on the components of sarcopenia in geriatric rehabilitation and to examine whether changes in different settings are associated with sarcopenia. DATA SOURCES: PubMed, the Cochrane Central Register of Controlled Trials in the Cochrane Library, and Embase were searched from initiation to August 30, 2021. STUDY SELECTION: We included randomized controlled trials of older adults receiving geriatric rehabilitation that included strength exercise training. DATA EXTRACTION: The following study contents were extracted: study design, patient characteristics, sample size, description of the rehabilitation setting, follow-up time point, and outcomes. The main outcomes were muscle mass, muscle strength, and physical performance. DATA SYNTHESIS: Weighted mean difference for Timed Up and Go score and standardized mean difference for other parameters were calculated. CONCLUSIONS: Center-based geriatric rehabilitation improved lower limb strength and Timed Up and Go test score to a greater extent than home-based geriatric rehabilitation in elderly people. Center-based training seems to show a minor superior effect on gait speed in prolonged follow-up rather than at the endpoint of intervention. To draw a stronger conclusion, further high-quality trials with standard protocols and longer follow-up are needed.


Assuntos
Sarcopenia , Idoso , Terapia por Exercício/métodos , Humanos , Força Muscular/fisiologia , Equilíbrio Postural , Estudos de Tempo e Movimento
11.
Inorg Chem ; 60(16): 11756-11763, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34242019

RESUMO

Terminal ligand exchange and framework linker exchange have been frequently practiced as powerful tools to functionalize reticular structures such as metal-organic frameworks (MOFs). Herein, we report the postsynthetic modification (PSM) of a 6-connected layered MOF (hxl topology) to achieve a 12-connected fcu framework. In the PSM process, isometric linker exchange in the layers and linker installation between adjacent layers by the substitution of modulating ligands happen simultaneously. Snapshots of PSM at different time points reveal that the hxl domain is adaptively reorganized to create sites for new linker installation, and gradually the fcu domain dominates the crystal. Detailed kinetic analysis suggests that, although adaptive linker installation requires interlayer expansion of stackings in situ, it is kinetically faster than isometric linker exchange in the layers.

12.
Angew Chem Int Ed Engl ; 60(5): 2534-2540, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33078563

RESUMO

A new metal-organic framework (MOF) with both coordination linkages and covalent linkages is prepared by coordinating CuI with pyrazolate for an aldehyde-functionalized trinuclear complex, and subsequent imine condensation with p-phenylenediamine, a reaction typical for covalent organic framework (COF) synthesis. This MOF×COF collaboration yields FDM-71 with honeycomb layers stacked in eclipsed fashion. After dissociating the CuI -pyrazolate coordination in FDM-71, the obtained organic components carry the information of structural defects, and thus vacancy identity (aldehyde-based unit vacancy and amine-based unit vacancy) and concentration are definitely resolved. Further to the redox catalytic activity inherited from the complex, FDM-71 features effective photosensitizing activity. The two functions integrated in one well-defined structure is demonstrated by its high efficiency in decomposing H2 O2 and consequent excitation of O2 to reactive oxygen species.

13.
BMC Cardiovasc Disord ; 20(1): 145, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32204696

RESUMO

BACKGROUND: We hypothesized that discriminating the early subclinical organ damage would serve as a great opportunity for prevention against atherosclerotic cardiovascular disease (ASCVD). Brachial-ankle pulse wave velocity (baPWV), low retinal vascular fractal dimension, and albuminuria are surrogates of subclinical vascular changes. METHODS: The aim of this study was to use Pooled Cohort Equations (PCE) and ASCVD risk equations derived from "Prediction for ASCVD Risk in China project (CHINA-PAR)" to observe the prevalence of macro- and microcirculation abnormalities. A total of 2166 subjects were involved. Characteristics were investigated using questionnaire and physical examinations. We calculated the urine albumin to creatinine ratio (UACR). The baPWV was measured using a fully automatic arteriosclerosis detector. The retinal vascular fractal dimension was measured by a semiautomated computer-based program. The 10-year ASCVD risk was estimated using the PCE and CHINA-PAR model. RESULTS: The cut-off values for the elevated baPWV were 2.82 and 2.92% in the PCE model and CHINA-PAR model, respectively, with nearly 85% sensitivity and an average specificity of 74%. For low retinal fractal dimension, at the cut-off point of 3.8%, we acquired an acceptable sensitivity of 66.27-68.24% and specificity of 62.57-67.45%. All the C-statistics presented a significant improvement from the PCE model to the CHINA-PAR model (P < 0.05). For all categories-net reclassification improvement (NRI) values were significant and clearly varied (0.329, 0.183, and 0.104, respectively) depending on the cut-off set at 3%. CONCLUSION: Our study demonstrated that the CHINA-PAR equations rather than PCE could provide better identification of macro- and microcirculation abnormalities. A lower cut-off point for the subclinical vascular changes may be selected in a population from southeast China.


Assuntos
Aterosclerose/diagnóstico , Indicadores Básicos de Saúde , Microcirculação , Adulto , Albuminúria/diagnóstico , Albuminúria/fisiopatologia , Índice Tornozelo-Braço , Povo Asiático , Aterosclerose/etnologia , Aterosclerose/patologia , Aterosclerose/fisiopatologia , China/epidemiologia , Estudos Transversais , Feminino , Fractais , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Fotografação , Valor Preditivo dos Testes , Prevalência , Análise de Onda de Pulso , Vasos Retinianos/patologia , Medição de Risco , Fatores de Risco
14.
J Am Chem Soc ; 141(28): 11322-11327, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31265260

RESUMO

With tunable pore size and rich active metal centers, metal-organic frameworks (MOFs) have been regarded as the one of the promising materials for catalysis. Prospectively, employing MOFs in electrochemistry would notably broaden the scope of electrocatalysis. However, this application is largely hindered by MOFs' conventionally poor electrical conductivity. Integrating MOFs without compromising their crystalline superiority holds a grand challenge to unveil their pristine electrocatalytic properties. In this work, we introduce an epitaxial growth strategy to accomplish the efficient integration of the insulating MOFs into electrochemistry. Particularly, with pristine-graphene-templated growth, the two-dimensional (2D) single-crystal MOF possesses a large lateral size of ∼23 µm and high aspect ratio up to ∼1500 and exhibits a significant electrochemical enhancement, with a charge transfer resistance of ∼200 ohm and a 30 mA cm-2 current density at only 0.53 V versus a reversible hydrogen electrode. The epitaxial strategy could be further applied to other 2D substrates, such as MoS2. This MOF/graphene 2D architecture sheds light on integrating insulating MOFs into electrochemical applications.

15.
J Am Chem Soc ; 141(6): 2348-2355, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30636404

RESUMO

Encapsulation of biomacromolecules in metal-organic frameworks (MOFs) can preserve biological functionality in harsh environments. Despite the success of this approach, termed biomimietic mineralization, limited consideration has been given to the chemistry of the MOF coating. Here, we show that enzymes encapsulated within hydrophilic MAF-7 or ZIF-90 retain enzymatic activity upon encapsulation and when exposed to high temperatures, denaturing or proteolytic agents, and organic solvents, whereas hydrophobic ZIF-8 affords inactive catalase and negligible protection to urease.


Assuntos
Enzimas Imobilizadas/química , Interações Hidrofóbicas e Hidrofílicas , Estruturas Metalorgânicas/química , Cápsulas , Catalase/química , Catalase/metabolismo , Enzimas Imobilizadas/metabolismo , Modelos Moleculares , Conformação Proteica , Desnaturação Proteica , Temperatura , Urease/química , Urease/metabolismo
16.
Med Sci Monit ; 25: 9973-9980, 2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31875645

RESUMO

BACKGROUND As epidemiological findings are still controversial, animal experiments have probed into the potential link between uric acid and damage to microvessels. The present study examined the association of serum uric acid (SUA) with the retinal vascular caliber and retinal vascular fractal dimension (Df) in males and females utilizing a cross-sectional study design. MATERIAL AND METHODS A total of 2169 subjects from 7 sampling units were enrolled. Retinal vascular parameters were analyzed with a semi-automated computer-based program. The central retinal arteriolar equivalent, central retinal venular equivalent, and Df were linearly and categorically measured in males and females and at various SUA levels. RESULTS The analysis revealed that per SD SUA increase was associated with an increase of 0.848 µm in the arteriolar caliber, and an increase of 1.618 µm in the venular caliber only in females. No significant correlation was found between Df and SUA in females or in males. Further adjusted for more cardiovascular risk factors did not change the results. CONCLUSIONS By exploring a Chinese coastal population, we elucidate the association between SUA with retinal arterioles and venules in females. Df, as a mathematical index of retinal blood vascular complexity, is not correlated with SUA or hyperuricemia.


Assuntos
Microvasos/metabolismo , Retina/metabolismo , Ácido Úrico/metabolismo , Adulto , Arteríolas/metabolismo , Povo Asiático , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Hiperuricemia/metabolismo , Masculino , Pessoa de Meia-Idade , Vasos Retinianos/metabolismo , Fatores de Risco , Caracteres Sexuais , Ácido Úrico/análise , Ácido Úrico/sangue , Vênulas/metabolismo
17.
Angew Chem Int Ed Engl ; 58(16): 5348-5353, 2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30776186

RESUMO

Positioning a diverse set of building blocks in a well-defined array enables cooperativity amongst them and the systematic programming of functional properties. The extension of this concept to porous metal-organic frameworks (MOFs) is challenging since the installation of multiple components in a well-ordered framework requires careful design of the lattice topology, judicious selection of building blocks, and precise control of the crystallization parameters. Herein, we report how we met these challenges to prepare the first quinary MOF structure, FDM-8, by bottom-up self-assembly from two metals, ZnII and CuI , and three distinct carboxylate- and pyrazolate-based linkers. With a surface area of 3643 m2 g-1 , FDM-8 contains hierarchical pores and shows outstanding methane-storage capacity at high pressure. Furthermore, functional groups introduced on the linkers became compartmentalized in predetermined arrays in the pores of the FDM-8 framework.

18.
J Am Chem Soc ; 139(23): 7998-8007, 2017 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-28541696

RESUMO

Inorganic functionalization of metal-organic frameworks (MOFs), such as incorporation of multiple inorganic building blocks with distinct metals into one structure and further modulation of the metal charges, endows the porous materials with significant properties toward their applications in catalysis. In this work, by an exploration of the role of 4-pyrazolecarboxylic acid (H2PyC) in the formation of trinuclear copper pyrazolate as a metalloligand in situ, four new MOFs with multiple components in order were constructed through one-pot synthesis. This metalloligand strategy provides multicomponent MOFs with new topologies (tub for FDM-4 and tap for FDM-5) and is also compatible with a second organic linker for cooperative construction of complex MOFs (1,4-benzenedicarboxylic acid for FDM-6 and 2,6-naphthalenedicarboxylic acid for FDM-7). The component multiplicity of these MOFs originates from PyC's ability to separate Cu and Zn on the basis of their differentiated binding affinities toward pyrazolate and carboxylate. These MOFs feature reversible and facile redox transformations between CuI3(PyC)3 and CuII3(µ-OH)(PyC)3(OH)3 without altering the connecting geometries of the units, thus further contributing to the significant catalytic activities in the oxidation of CO and aromatic alcohols and the decomposition of H2O2. This study on programming multiple inorganic components into one framework and modulating their electronic structures is an example of functionalizing the inorganic units of MOFs with a high degree of control.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA