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1.
Eye‐Catching Dual‐Fluorescent Dynamic Metal–Organic Framework Senses Traces of Water: Experimental Findings and Theoretical Correlation 下载免费PDF全文
Dr. Biswajit Bhattacharya Arijit Halder Lopa Paul Dr. Swapan Chakrabarti Dr. Debajyoti Ghoshal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):14998-15005
A guest‐dependent dynamic fivefold interpenetrated 3D porous metal–organic framework (MOF) of ZnII ions has been synthesized that exhibits selective carbon dioxide adsorption. Furthermore, the MOF shows excellent luminescence behavior, which is supported by a systematic study on the guest‐responsive multicolor emission of a suspension of the MOF. The dual‐emission behavior arises from the excited‐state intramolecular proton transfer (ESIPT), and the compound also shows remarkable potential to detect traces of water in various organic solvents. The experimental observations were also painstakingly authenticated by using time‐dependent density‐functional‐theory (DFT) calculations. 相似文献
2.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(11):3082-3086
The aluminum‐based metal–organic framework (MOF) made from 2‐aminoterephthalate is a photocatalyst for oxygen evolution. This MOF can be modified by incorporating Ni2+ cations into the pores through coordination to the amino groups, and the resulting MOF is an efficient photocatalyst for overall water splitting. 相似文献
3.
Zhicheng Zhang Yifeng Chen Xiaobin Xu Jingchao Zhang Guolei Xiang Wei He Prof. Xun Wang 《Angewandte Chemie (International ed. in English)》2014,53(2):429-433
Metal–organic frameworks (MOFs) have demonstrated great potentials in a variety of important applications. To enhance the inherent properties and endow materials with multifunctionality, the rational design and synthesis of MOFs with nanoscale porosity and hollow feature is highly desired and remains a great challenge. In this work, the formation of a series of well‐defined MOF (MOF‐5, FeII‐MOF‐5, FeIII‐MOF‐5) hollow nanocages by a facile solvothermal method, without any additional supporting template is reported. A surface‐energy‐driven mechanism may be responsible for the formation of hollow nanocages. The addition of pre‐synthesized poly(vinylpyrrolidone)‐ (PVP) capped noble‐metal nanoparticles into the synthetic system of MOF hollow nanocages yields the yolk–shell noble metal@MOF nanostructures. The present strategy to fabricate hollow and yolk–shell nanostructures is expected to open up exciting opportunities for developing a novel class of inorganic–organic hybrid functional nanomaterials. 相似文献
4.
Fei‐Long Li Pengtang Wang Xiaoqing Huang David James Young Hui‐Fang Wang Pierre Braunstein Jian‐Ping Lang 《Angewandte Chemie (International ed. in English)》2019,58(21):7051-7056
Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm?2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec?1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. 相似文献
5.
Fei‐Long Li Pengtang Wang Xiaoqing Huang David James Young Hui‐Fang Wang Pierre Braunstein Jian‐Ping Lang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):7125-7130
Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm?2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec?1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. 相似文献
6.
Jialuo Li Shuai Yuan Jun‐Sheng Qin Jiandong Pang Peng Zhang Yingmu Zhang Yanyan Huang Hannah F. Drake Wenshe R. Liu Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2020,59(24):9319-9323
The controlled synthesis of multicomponent metal–organic frameworks (MOFs) allows for the precise placement of multiple cooperative functional groups within a framework, leading to emergent synergistic effects. Herein, we demonstrate that turn‐on fluorescence sensors can be assembled by combining a fluorophore and a recognition moiety within a complex cavity of a multicomponent MOF. An anthracene‐based fluorescent linker and a hemicyanine‐containing CN?‐responsive linker were sequentially installed into the lattice of PCN‐700. The selective binding of CN? to hemicyanine inhibited the energy transfer between the two moieties, resulting in a fluorescence turn‐on effect. Taking advantage of the high tunability of the MOF platform, the ratio between anthracene and the hemicyanine moiety could be fine‐tuned in order to maximize the sensitivity of the overall framework. The optimized MOF‐sensor had a CN?‐detection limit of 0.05 μm , which is much lower than traditional CN? fluorescent sensors (about 0.2 μm ). 相似文献
7.
Hongye Yuan Jifang Tao Nanxi Li Avishek Karmakar Chunhua Tang Hong Cai Stephen John Pennycook Navab Singh Dan Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(40):14227-14232
Gas sensing technologies for smart cities require miniaturization, cost‐effectiveness, low power consumption, and outstanding sensitivity and selectivity. On‐chip, tailorable capacitive sensors integrated with metal–organic framework (MOF) films are presented, in which abundant coordinatively unsaturated metal sites are available for gas detection. The in situ growth of homogeneous Mg‐MOF‐74 films is realized with an appropriate metal‐to‐ligand ratio. The resultant sensors exhibit selective detection for benzene vapor and carbon dioxide (CO2) at room temperature. Postsynthetic modification of Mg‐MOF‐74 films with ethylenediamine decreases sensitivity toward benzene but increases selectivity to CO2. The reduced porosity and blocked open metal sites caused by amine coordination account for a deterioration in the sensing performance for benzene (by ca. 60 %). The enhanced sensitivity for CO2 (by ca. 25 %) stems from a tailored amine–CO2 interaction. This study demonstrates the feasibility of tuning gas sensing properties by adjusting MOF–analyte interactions, thereby offering new perspectives for the development of MOF‐based sensors. 相似文献
8.
Design and Synthesis of a Water‐Stable Anionic Uranium‐Based Metal–Organic Framework (MOF) with Ultra Large Pores 下载免费PDF全文
Dr. Peng Li Dr. Nicolaas A. Vermeulen Xirui Gong Dr. Christos D. Malliakas Prof. J. Fraser Stoddart Prof. Joseph T. Hupp Prof. Omar K. Farha 《Angewandte Chemie (International ed. in English)》2016,55(35):10358-10362
Ionic metal–organic frameworks (MOFs) are a subclass of porous materials that have the ability to incorporate different charged species in confined nanospace by ion‐exchange. To date, however, very few examples combining mesoporosity and water stability have been realized in ionic MOF chemistry. Herein, we report the rational design and synthesis of a water‐stable anionic mesoporous MOF based on uranium and featuring tbo‐type topology. The resulting tbo MOF exhibits exceptionally large open cavities (3.9 nm) exceeding those of all known anionic MOFs. By supercritical CO2 activation, a record‐high Brunauer‐Emmett‐Teller (BET) surface area (2100 m2 g?1) for actinide‐based MOFs has been obtained. Most importantly, however, this new uranium‐based MOF is water‐stable and able to absorb positively charged ions selectively over negatively charged ones, enabling the efficient separation of organic dyes and biomolecules. 相似文献
9.
Carl K. Brozek Dr. Luca Bellarosa Tomohiro Soejima Talia V. Clark Prof. Núria López Prof. Mircea Dincă 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(23):6871-6874
We investigated which factors govern the critical steps of cation exchange in metal–organic frameworks by studying the effect of various solvents on the insertion of Ni2+ into MOF‐5 and Co2+ into MFU‐4l. After plotting the extent of cation insertion versus different solvent parameters, trends emerge that offer insight into the exchange processes for both systems. This approach establishes a method for understanding critical aspects of cation exchange in different MOFs and other materials. 相似文献
10.
Switch‐On Fluorescence of a Perylene‐Dye‐Functionalized Metal–Organic Framework through Postsynthetic Modification 下载免费PDF全文
Dr. Christian Dietl Henrik Hintz Dr. Bastian Rühle Prof. Dr. Jörn Schmedt auf der Günne Prof. Dr. Heinz Langhals Dr. Stefan Wuttke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(30):10714-10720
A perylene dye was introduced directly as a linker into a metal–organic framework (MOF) during synthesis. Depending on the dye concentration in the MOF synthesis mixture, different fluorescent materials were generated. The successful incorporation of the dye was proven by using 13C and 27Al MAS NMR spectroscopy, by solution NMR spectroscopy after digestion of the MOF sample, and by synthesizing a reference dye without connecting groups, which could coordinate on the metal–oxo cluster inside the MOF. Fluorescence quenching effects of the MOF linker, 2‐aminoterephthalate, were observed and overcome by postsynthetic modification with acetic anhydride. We show here for the first time that amino groups, which can be used as anchoring points for covalent attachment of other molecules, are responsible for fluorescence quenching. Thus, a very promising strategy to implement switchable fluorescence into MOFs is shown here. 相似文献
11.
Versatile Tailoring of Paddle‐Wheel ZnII Metal–Organic Frameworks through Single‐Crystal‐to‐Single‐Crystal Transformations 下载免费PDF全文
Tapan K. Pal Dr. Subhadip Neogi Prof. Parimal K. Bharadwaj 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):16083-16090
A new tetracarboxylate ligand having short and long arms formed 2D layer ZnII coordination polymer 1 with paddle‐wheel secondary building units under solvothermal conditions. The framework undergoes solvent‐specific single crystal‐to‐single crystal (SC‐SC) transmetalation to produce 1Cu . With a sterically encumbered dipyridyl linker, the same ligand forms non‐interpenetrated, 3D, pillared‐layer ZnII metal–organic framework (MOF) 2 , which takes part in SC‐SC linker‐exchange reactions to produce three daughter frameworks. The parent MOF 2 shows preferential incorporation of the longest linker in competitive linker‐exchange experiments. All the 3D MOFs undergo complete SC‐SC transmetalation with CuII, whereby metal exchange in different solvents and monitoring of X‐ray structures revealed that bulky solvated metal ions lead to ordering of the shortest linker in the framework, which confirms that the solvated metal ions enter through the pores along the linker axis. 相似文献
12.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(45):14199-14203
A straightforward crack‐patterning method is reported allowing the direct formation of periodic cracks in metal–organic framework (MOF) nanoparticle films during dip‐coating deposition. The crack propagation and periodicity can be easily tailored by controlling the evaporation front and the withdrawal speed. Several MOF‐patterned films can be fabricated on large surfaces and on several substrates (flat, curved or flexible) including the inner surface of a tube, not achievable by other lithographic techniques. We demonstrate that the periodic cracked arrays diffract light and, due to the MOF sorption properties, photonic vapor sensors are fabricated. A new concept of “in‐tube”, MOF‐based diffraction grating sensors is proposed with outstanding sensitivity that can be easily tuned “on‐demand” as function of the desired detection range. 相似文献
13.
Efficient Visible‐Light‐Driven Carbon Dioxide Reduction by a Single‐Atom Implanted Metal–Organic Framework 下载免费PDF全文
Dr. Huabin Zhang Dr. Jing Wei Dr. Juncai Dong Dr. Guigao Liu Li Shi Dr. Pengfei An Dr. Guixia Zhao Dr. Jintao Kong Dr. Xiaojun Wang Dr. Xianguang Meng Prof. Jing Zhang Prof. Jinhua Ye 《Angewandte Chemie (International ed. in English)》2016,55(46):14310-14314
Modular optimization of metal–organic frameworks (MOFs) was realized by incorporation of coordinatively unsaturated single atoms in a MOF matrix. The newly developed MOF can selectively capture and photoreduce CO2 with high efficiency under visible‐light irradiation. Mechanistic investigation reveals that the presence of single Co atoms in the MOF can greatly boost the electron–hole separation efficiency in porphyrin units. Directional migration of photogenerated excitons from porphyrin to catalytic Co centers was witnessed, thereby achieving supply of long‐lived electrons for the reduction of CO2 molecules adsorbed on Co centers. As a direct result, porphyrin MOF comprising atomically dispersed catalytic centers exhibits significantly enhanced photocatalytic conversion of CO2, which is equivalent to a 3.13‐fold improvement in CO evolution rate (200.6 μmol g?1 h?1) and a 5.93‐fold enhancement in CH4 generation rate (36.67 μmol g?1 h?1) compared to the parent MOF. 相似文献
14.
Photoinduced Postsynthetic Polymerization of a Metal–Organic Framework toward a Flexible Stand‐Alone Membrane 下载免费PDF全文
Yuanyuan Zhang Dr. Xiao Feng Haiwei Li Yifa Chen Jingshu Zhao Shan Wang Lu Wang Prof. Dr. Bo Wang 《Angewandte Chemie (International ed. in English)》2015,54(14):4259-4263
Metal–organic frameworks (MOFs) are a promising class of nanoporous polymeric materials. However, the processing of such fragile crystalline powders into desired shapes for further applications is often difficult. A photoinduced postsynthetic polymerization (PSP) strategy was now employed to covalently link MOF crystals by flexible polymer chains, thus endowing the MOF powders with processability and flexibility. Nanosized UiO‐66‐NH2 was first functionalized with polymerizable functional groups, and its subsequent copolymerization with monomers was easily induced by UV light under solvent‐free and mild conditions. Because of the improved interaction between MOF particles and polymer chains, the resulting stand‐alone and elastic MOF‐based PSP‐derived membranes possess crack‐free and uniform structures and outstanding separation capabilities for CrVI ions from water. 相似文献
15.
Selective Sensing of Fe3+ and Al3+ Ions and Detection of 2,4,6‐Trinitrophenol by a Water‐Stable Terbium‐Based Metal–Organic Framework 下载免费PDF全文
Li‐Hui Cao Fang Shi Wen‐Min Zhang Prof. Shuang‐Quan Zang Prof. Thomas C. W. Mak 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(44):15705-15712
A water‐stable luminescent terbium‐based metal–organic framework (MOF), {[Tb(L1)1.5(H2O)] ? 3 H2O}n (Tb‐MOF), with rod‐shaped secondary building units (SBUs) and honeycomb‐type tubular channels has been synthesized and structurally characterized by single‐crystal X‐ray diffraction. The high green emission intensity and the microporous nature of the Tb‐MOF indicate that it can potentially be used as a luminescent sensor. In this work, we show that Tb‐MOF can selectively sense Fe3+ and Al3+ ions from mixed metal ions in water through different detection mechanisms. In addition, it also exhibits high sensitivity for 2,4,6‐trinitrophenol (TNP) in the presence of other nitro aromatic compounds in aqueous solution by luminescence quenching experiments. 相似文献
16.
Dr. Weiting Yang Dr. Jing Feng Dr. Shuyan Song Prof. Dr. Hongjie Zhang 《Chemphyschem》2012,13(11):2734-2738
Miniaturizing the size of metal‐organic framework (MOF) crystals to the nanometer scale is challenging, but it provides more advanced applications without changing the characteristic features itself. It is especially useful to investigate the correlation between the porous properties and the interfacial structures of nanocrystals. Using amino acids as capping agents, nanoscale Tb‐MOF‐76 is fabricated rapidly by means of microwave‐assisted methods. Both the modular effects of the amimo acids and the acid–base environment of the reaction medium have an important impact on the morphologies and dimensions of Tb‐MOF‐76. The structures of the samples are confirmed by powder X‐ray diffraction, and the morphologies are characterized by SEM. Photoluminescence studies reveal that these Tb‐MOF‐76 materials exhibit a green emission corresponding to the transition 5D4→7FJ of Tb3+ ions under UV‐light excitation, which is sensitive to small organic molecules in solution. 相似文献
17.
Chengyu Liang Shitong Zhang Liwei Cheng Jian Xie Fuwan Zhai Yihui He Yaxing Wang Zhifang Chai Shuao Wang 《Angewandte Chemie (International ed. in English)》2020,59(29):11856-11860
Semiconductive metal–organic frameworks (MOFs) have emerged in applications such as chemical sensors, electrocatalysts, energy storage materials, and electronic devices. However, examples of semiconductive MOFs within flexible electronics have not been reported. We present flexible X‐ray detectors prepared by thermoplastic dispersal of a semiconductive MOF ( SCU‐13 ) through a commercially available polymer, poly(vinylidene fluoride). The flexible detectors exhibit efficient X‐ray‐to‐electric current conversion with enhanced charge‐carrier mobility and low trap density compared to pelleted devices. A high X‐ray detection sensitivity of 65.86 μCGyair?1 cm?2 was achieved, which outperforms other pelleted devices and commercial flexible X‐ray detectors. We demonstrate that the MOF‐based flexible detectors can be operated at multiple bending angles without a deterioration in detection performance. As a proof‐of‐concept, an X‐ray phase contrast under bending conditions was constructed using a 5×5 pixelated MOF‐based imager. 相似文献
18.
Photocatalyzed Hydrogen Evolution from Water by a Composite Catalyst of NH2‐MIL‐125(Ti) and Surface Nickel(II) Species 下载免费PDF全文
Prof. Dr. Jordi Llorca Prof. Dr. Hicham Idriss Dr. Marco Ranocchiari Prof. Dr. Jeroen A. van Bokhoven 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(39):13894-13899
A composite of the metal–organic framework (MOF) NH2‐MIL‐125(Ti) and molecular and ionic nickel(II) species, catalyzed hydrogen evolution from water under UV light. In 95 v/v % aqueous conditions the composite produced hydrogen in quantities two orders of magnitude higher than that of the virgin framework and an order of magnitude greater than that of the molecular catalyst. In a 2 v/v % water and acetonitrile mixture, the composite demonstrated a TOF of 28 mol H2 g(Ni)?1 h?1 and remained active for up to 50 h, sustaining catalysis for three times longer and yielding 20‐fold the amount of hydrogen. Appraisal of physical mixtures of the MOF and each of the nickel species under identical photocatalytic conditions suggest that similar surface localized light sensitization and proton reduction processes operate in the composite catalyst. Both nickel species contribute to catalytic conversion, although different activation behaviors are observed. 相似文献
19.
Jun‐Hua Wei Jing‐Wei Yi Min‐Le Han Bo Li Shan Liu Ya‐Pan Wu Lu‐Fang Ma Dong‐Sheng Li 《化学:亚洲杂志》2019,14(20):3694-3701
Effective detection of organic/inorganic pollutants, such as antibiotics, nitro‐compounds, excessive Fe3+ and MnO4?, is crucial for human health and environmental protection. Here, a new terbium(III)–organic framework, namely [Tb(TATAB)(H2O)]?2H2O ( Tb‐MOF , H3TATAB=4,4′,4′′‐s‐triazine‐1,3,5‐triyltri‐m‐aminobenzoic acid), was assembled and characterized. The Tb‐MOF exhibits a water‐stable 3D bnn framework. Due to the existence of competitive absorption, Tb‐MOF has a high selectivity for detecting Fe3+, MnO4?, 4‐nirophenol and nitroimidazole (ronidazole, metronidazole, dimetridazole, ornidazole) in aqueous through luminescent quenching. The results suggest that Tb‐MOF is a simple and reliable reagent with multiple sensor responses in practical applications. To the best of our knowledge, this work represents the first TbIII‐based MOF as an efficient fluorescent sensor for detecting metal ions, inorganic anions, nitro‐compounds, and antibiotics simultaneously. 相似文献
20.
Huanrong Wang Lin Han Dong Zheng Mingfang Yang Yassin H. Andaloussi Peng Cheng Zhenjie Zhang Shengqian Ma Michael J. Zaworotko Yifan Feng Yao Chen 《Angewandte Chemie (International ed. in English)》2020,59(15):6263-6267
Fabrication of zeolite‐like metal–organic frameworks (ZMOFs) for advanced applications, such as enzyme immobilization, is of great interest but is a great synthetic challenge. Herein, we have developed a new strategy using proteins as structure‐directed agents to direct the formation of new ZMOFs that can act as versatile platforms for the in situ encapsulation of proteins under ambient conditions. Notably, protein incorporation directs the formation of a ZMOF with a sodalite ( sod ) topology instead of a non‐porous diamondoid ( dia ) topology under analogous synthetic conditions. Histidines in proteins play a crucial role in the observed templating effect. Modulating histidine content thereby influenced the resultant MOF product (from dia to dia + sod mixture and, ultimately, to sod MOF). Moreover, the resulting ZMOF‐incorporated proteins preserved their activity even after exposure to high temperatures and organic solvents, demonstrating their potential for biocatalysis and biopharmaceutical applications. 相似文献