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51.
Dr. Jian Yang Dr. Ke Li Prof. Chunzhong Li Prof. Jinlou Gu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23152-23156
Apyrase is an important family of extracellular enzymes that catalyse the hydrolysis of high-energy phosphate bonds (HEPBs) in ATP and ADP, thereby modulating many physiological processes and driving life activities. Herein, we report an unexpected discovery that cerium-based metal–organic frameworks (Ce-MOFs) of UiO-66(Ce) have intrinsic apyrase-like activity for ATP/ADP-related physiological processes. The abundant CeIII/CeIV couple sites of Ce-MOFs endow them with the ability to selectively catalyse the hydrolysis of HEPBs of ATP and ADP under physiological conditions. Compared to natural enzymes, they could resist extreme pH and temperature, and present a broad range of working conditions. Based on this finding, a significant inhibitory effect on ADP-induced platelet aggregation was observed upon exposing the platelet-rich plasma (PRP) to the biomimetic UiO-66(Ce) films, prefiguring their wide application potentials in medicine and biotechnology. 相似文献
52.
We briefly report experimental observations of striped patterns in the menisci of free-standing smectic C films. The results were obtained with a mesogenic compound that transits directly from the nematic phase to the smectic C phase, without an intermediate smectic A phase. In this case, it is shown that stripes do not correspond to undulations of the smectic free surface and smectic layers, as was indeed evidenced in previous studies with other compounds and different phase sequences. Hence, our results show that the nature of striped patterns in free-standing films depends on the phase sequence of the considered materials. Further experimental and theoretical works are still required to fully elucidate the physical mechanisms that drive the onset of patterns in such systems. 相似文献
53.
Post‐Synthetic Ligand Exchange in Zirconium‐Based Metal–Organic Frameworks: Beware of The Defects!
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Dr. Marco Taddei Dr. Russell J. Wakeham Athanasios Koutsianos Dr. Enrico Andreoli Prof. Andrew R. Barron 《Angewandte Chemie (International ed. in English)》2018,57(36):11706-11710
Post‐synthetic ligand exchange in the prototypical zirconium‐based metal–organic framework (MOF) UiO‐66 was investigated by in situ solution 1H NMR spectroscopy. Samples of UiO‐66 having different degrees of defectivity were exchanged using solutions of several terephthalic acid analogues in a range of conditions. Linker exchange only occurred in defect‐free UiO‐66, whereas monocarboxylates grafted at defect sites were found to be preferentially exchanged with respect to terephthalic acid over the whole range of conditions investigated. A 1:1 exchange ratio between the terephthalic acid analogue and modulator was observed, providing evidence that the defects had missing‐cluster nature. Ex situ characterisation of the MOF powders after exchange corroborated these findings and showed that the physical‐chemical properties of the MOF depend on whether the functionalisation occurs at defective sites or on the framework. 相似文献
54.
Xinyu Yang Shuai Yuan Dr. Lanfang Zou Hannah Drake Yingmu Zhang Dr. Junsheng Qin Dr. Ali Alsalme Dr. Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2018,57(15):3927-3932
Epitaxial growth of MOF‐on‐MOF composite is an evolving research topic in the quest for multifunctional materials. In previously reported methods, the core–shell MOFs were synthesized via a stepwise strategy that involved growing the shell‐MOFs on top of the preformed core‐MOFs with matched lattice parameters. However, the inconvenient stepwise synthesis and the strict lattice‐matching requirement have limited the preparation of core–shell MOFs. Herein, we demonstrate that hybrid core–shell MOFs with mismatching lattices can be synthesized under the guidance of nucleation kinetic analysis. A series of MOF composites with mesoporous core and microporous shell were constructed and characterized by optical microscopy, powder X‐ray diffraction, gas sorption measurement, and scanning electron microscopy. Isoreticular expansion of microporous shells and orthogonal modification of the core was realized to produce multifunctional MOF composites, which acted as size selective catalysts for olefin epoxidation with high activity and selectivity. 相似文献
55.
Metal–organic frameworks (MOFs) are emerging porous coordination polymers constructed by metal ions and organic linkers that have attracted numerous interests in recent years. The large surface area, high porosity, tunable size, and versatile functionality make them promising materials for cargo delivery (i.e., drugs, mRNA, dyes) and sensing (i.e., nucleic acids, small molecules, ions). In addition, the metal ions released from MOFs offer antibacterial and antifungal utility. This review presents a snapshot of current MOF-related research, highlighting the synthesis approaches, and the various bioapplications of MOFs in terms of biosensing platforms, drug delivery, and antimicrobial agents, exposing potential for future research in the MOF field. 相似文献
56.
Muhammad Saeed Aswa Firdous Muhammad Saleh Zaman Fatima Izhar Mubeshar Riaz Sabah Haider Muzamil Majeed Shahzaib Tariq 《中国化学会会志》2023,70(4):789-824
Nowadays, desulfurization of fuel oil has raised concern globally because of strict industrial and environmental legislations. Albeit hydrodesulfurization (HDS) has been extensively used in oil refineries to produce low sulfur oil (< 10 ppm) but not been proven as effective method for the removal of dibenzothiophene (DBT), benzothiophene (TH) and their derivatives. Subsequently, adsorptive desulfurization (ADS) and oxidative desulfurization (ODS) methods have been developed to achieve high removal efficiency. In the past decade, metal–organic frameworks (MOFs) and its composites as oxidative catalysts, as well as adsorbents, have attracted the researchers owing to high surface area, tunable properties, and reusable. The present review comprises use of MOFs and their composites for the removal of sulfur from fuel oil via ODS and ADS processes. Additionally, physicochemical properties of MOFs, mechanism, pros and cons of both process, regeneration, and future challenges have been discussed briefly. Moreover, current limitations and future prospective are also discussed. 相似文献
57.
Dr. Ziqian Xue Dr. Jia-Jia Zheng Dr. Yusuke Nishiyama Dr. Ming-Shui Yao Dr. Yoshitaka Aoyama Zeyu Fan Dr. Ping Wang Prof. Takashi Kajiwara Prof. Yoshiki Kubota Prof. Satoshi Horike Prof. Ken-ichi Otake Prof. Susumu Kitagawa 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202215234
Exploring new porous coordination polymers (PCPs) that have tunable structure and conductivity is attractive but remains challenging. Herein, fine pore structure engineering by ligand conformation control of naphthalene diimide (NDI)-based semiconducting PCPs with π stacking-dependent conductivity tunability is achieved. The π stacking distances and ligand conformation in these isoreticular PCPs were modulated by employing metal centers with different coordination geometries. As a result, three conjugated PCPs (Co−pyNDI, Ni−pyNDI, and Zn−pyNDI) with varying pore structure and conductivity were obtained. Their crystal structures were determined by three-dimensional electron diffraction. The through-space charge transfer and tunable pore structure in these PCPs result in modulated selectivity and sensitivity in gas sensing. Zn−pyNDI can serve as a room-temperature operable chemiresistive sensor selective to acetone. 相似文献
58.
Qiu-Chen Peng Dr. Yu-Bing Si Jia-Wang Yuan Qi Yang Zi-Ying Gao Dr. Yuan-Yuan Liu Dr. Zhao-Yang Wang Dr. Kai Li Prof. Shuang-Quan Zang Prof. Ben Zhong Tang 《Angewandte Chemie (International ed. in English)》2023,62(40):e202308194
X-ray imaging technology has achieved important applications in many fields and has attracted extensive attentions. Dynamic X-ray flexible imaging for the real-time observation of the internal structure of complex materials is the most challenging type of X-ray imaging technology, which requires high-performance X-ray scintillators with high X-ray excited luminescence (XEL) efficiency as well as excellent processibility and stability. Here, a macrocyclic bridging ligand with aggregation-induced emission (AIE) feature was introduced for constructing a copper iodide cluster-based metal–organic framework (MOF) scintillator. This strategy endows the scintillator with high XEL efficiency and excellent chemical stability. Moreover, a regular rod-like microcrystal was prepared through the addition of polyvinyl pyrrolidone during the in situ synthesis process, which further enhanced the XEL and processibility of the scintillator. The microcrystal was used for the preparation of a scintillator screen with excellent flexibility and stability, which can be used for high-performance X-ray imaging in extremely humid environments. Furthermore, dynamic X-ray flexible imaging was realized for the first time. The internal structure of flexible objects was observed in real time with an ultrahigh resolution of 20 LP mm−1. 相似文献
59.
Prof. Dr. Dengrong Sun Lok Wing Wong Hok Yin Wong Ka Hei Lai Dr. Lin Ye Xinyao Xv Prof. Dr. Thuc Hue Ly Prof. Dr. Qingming Deng Prof. Dr. Jiong Zhao 《Angewandte Chemie (International ed. in English)》2023,62(4):e202216008
The direct utilization of metal–organic frameworks (MOFs) for electrocatalytic oxygen evolution reaction (OER) has attracted increasing interests. Herein, we employ the low-dose integrated differential phase contrast-scanning transmission electron microscopy (iDPC-STEM) technique to visualize the atomic structure of multivariate MOFs (MTV-MOFs) for guiding the structural design of bulk MOFs for efficient OER. The iDPC-STEM images revealed that incorporating Fe3+ or 2-aminoterephthalate (ATA) into Ni-BDC (BDC: benzenedicarboxylate) can introduce inhomogeneous lattice strain that weaken the coordination bonds, which can be selectively cleaved via a mild heat treatment to simultaneously generate coordinatively unsaturated metal sites, conductive Ni@C and hierarchical porous structure. Thus, excellent OER activity with current densities of 10 and 100 mA cm−2 are achieved over the defective MOFs at small overpotentials of 286 mV and 365 mV, respectively, which is superior to the commercial RuO2 catalyst and most of the bulk MOFs. 相似文献
60.
Dr. Feifei Zhang Dr. Hua Shang Bolun Zhai Zhiwei Zhao Dr. Yong Wang Prof. Libo Li Prof. Jinping Li Prof. Jiangfeng Yang 《Angewandte Chemie (International ed. in English)》2023,62(50):e202316149
Porous materials with d3 electronic configuration open metal sites have been proved to be effective adsorbents for N2 capture and N2/O2 separation. However, the reported materials remain challenging to address the trade-off between adsorption capacity and selectivity. Herein, we report a robust MOF, MIL-102Cr, that features two binding sites, can synergistically afford strong interactions for N2 capture. The synergistic adsorption site exhibits a benchmark Qst of 45.0 kJ mol−1 for N2 among the Cr-based MOFs, a record-high volumetric N2 uptake (31.38 cm3 cm−3), and highest N2/O2 selectivity (13.11) at 298 K and 1.0 bar. Breakthrough experiments reveal that MIL-102Cr can efficiently capture N2 from a 79/21 N2/O2 mixture, providing a record 99.99 % pure O2 productivity of 0.75 mmol g−1. In situ infrared spectroscopy and computational modelling studies revealed that a synergistic adsorption effect by open Cr(III) and fluorine sites was accountable for the strong interactions between the MOF and N2. 相似文献