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991.
Xingju Li Jiaqian Wang Qiao Yuan Xiangen Song Jiali Mu Yao Wei Li Yan Fanfei Sun Siquan Feng Yutong Cai Zheng Jiang Zhongkang Han Yunjie Ding 《Angewandte Chemie (International ed. in English)》2023,62(33):e202307570
Heterogeneous single-metal-site catalysts usually suffer from poor stability, thereby limiting industrial applications. Dual Pd1−Ru1 single-atom-sites supported on porous ionic polymers (Pd1−Ru1/PIPs) were constructed using a wetness impregnation method. The two isolated metal species in the form of a binuclear complex were immobilized on the cationic framework of PIPs through ionic bonds. Compared to the single Pd- or Ru-site catalyst, the dual single-atom system exhibits higher activity with 98 % acetylene conversion and near 100 % selectivity to dialkoxycarbonylation products, as well as better cycling stability for ten cycles without obvious decay. Based on DFT calculations, it was found that the single-Ru site exhibited a strong CO adsorption energy of −1.6 eV, leading to an increase in the local CO concentration of the catalyst. Notably, the Pd1−Ru1/PIPs catalyst had a much lower energy barrier of 2.49 eV compared to 3.87 eV of Pd1/PIPs for the rate-determining step. The synergetic effect between neighboring single sites Pd1 and Ru1 not only enhanced the overall activity, but also stabilized PdII active sites. The discovery of synergetic effects between single sites can deepen our understanding of single-site catalysts at the molecular level. 相似文献
992.
Bingyu Huang Xiannong Tang Yaoshuai Hong Longbin Li Prof. Ting Hu Prof. Kai Yuan Prof. Yiwang Chen 《Angewandte Chemie (International ed. in English)》2023,62(33):e202306667
Catalysts with metal-Nx sites have long been considered as effective electrocatalysts for oxygen reduction reaction (ORR), yet the accurate structure-property correlations of these active sites remain debatable. Report here is a proof-of-concept method to construct 1,4,8,11-tetraaza[14]annulene (TAA)-based polymer nanocomposites with well-managed electronic microenvironment via electron-donors/acceptors interaction of altering electron-withdrawing β-site substituents. DFT calculation proves the optimal −Cl substituted catalyst (CoTAA−Cl@GR) tailored the key OH* intermediate interaction with Co−N4 sites under the d-orbital regulation, hence reaching the top of ORR performance with excellent turnover frequency (0.49 e s−1 site−1). The combination of in situ scanning electrochemical microscopy and variable-frequency square wave voltammetry techniques contribute the great ORR kinetics of CoTAA−Cl@GR to the relatively high accessible site density (7.71×1019 site g−1) and fast electron outbound propagation mechanism. This work provides theoretical guidance for rational design of high-performance catalysts for ORR and beyond. 相似文献
993.
Dr. Wenjun Zhan Lingling Xu Zhiyu Liu Xiaoyang Liu Dr. Ge Gao Tiantian Xia Xiaotong Cheng Dr. Xianbao Sun Prof. Dr. Fu-Gen Wu Prof. Dr. Qian Yu Prof. Dr. Gaolin Liang 《Angewandte Chemie (International ed. in English)》2023,62(32):e202306427
Staphylococcus aureus (S. aureus) is able to hide within host cells to escape immune clearance and antibiotic action, causing life-threatening infections. To boost the therapeutic efficacy of antibiotics, new intracellular delivery approaches are urgently needed. Herein, by rational design of an adamantane (Ada)-containing antibiotic-peptide precursor Ada-Gly-Tyr-Val-Ala-Asp-Cys(StBu)-Lys(Ciprofloxacin)-CBT ( Cip-CBT-Ada ), we propose a strategy of tandem guest-host-receptor recognitions to precisely guide ciprofloxacin to eliminate intracellular S. aureus. Via guest-host recognition, Cip-CBT-Ada is decorated with a β-cyclodextrin-heptamannoside ( CD-M ) derivative to yield Cip-CBT-Ada/CD-M , which is able to target mannose receptor-overexpressing macrophages via multivalent ligand-receptor recognition. After uptake, Cip-CBT-Ada/CD-M undergoes caspase-1 (an overexpressed enzyme during S. aureus infection)-initiated CBT-Cys click reaction to self-assemble into ciprofloxacin nanoparticle Nano-Cip . In vitro and in vivo experiments demonstrate that, compared with ciprofloxacin or Cip-CBT-Ada , Cip-CBT-Ada/CD-M shows superior intracellular bacteria elimination and inflammation alleviation efficiency in S. aureus-infected RAW264.7 cells and mouse infection models, respectively. This work provides a supramolecular platform of tandem guest-host-receptor recognitions to precisely guide antibiotics to eliminate intracellular S. aureus infection efficiently. 相似文献
994.
Yinghao Xia Jili Li Linlin Wang Yuqi Xie Lili Zhang Xiaoyan Han Prof. Weihong Tan Prof. Yanlan Liu 《Angewandte Chemie (International ed. in English)》2023,62(4):e202214169
Precise regulation of vascular senescence represents a far-reaching strategy to combat age-related diseases. However, the high heterogeneity of senescence, alongside the lack of targeting and potent senolytics, makes it very challenging. Here we report a molecular design to tackle this challenge through multidimensional, hierarchical recognition of three hallmarks commonly shared among senescence, namely, aptamer-mediated recognition of a membrane marker for active cell targeting, a self-immolative linker responsive to lysosomal enzymes for switchable drug release, and a compound against antiapoptotic signaling for clearance. Such senolytic can target and trigger severe cell apoptosis in broad-spectrum senescent endothelial cells, and importantly, distinguish them from the quiescent state. Its potential for in vivo treatment of vascular diseases is successfully illustrated in a model of atherosclerosis, with effective suppression of the plaque progression yet negligible side effects. 相似文献
995.
Dr. Fan Zhang Dr. Yang Zhang Lixuan Sun Chengpeng Wei Huaqing Zhang Prof. Dr. Liang Wu Dr. Xiaolin Ge Prof. Dr. Tongwen Xu 《Angewandte Chemie (International ed. in English)》2023,62(4):e202215017
The McMurry coupling is a facile, gentle and low-cost chemical reaction for synthesizing. Here, for the first time, we employed the McMurry coupling reaction to prepare π-conjugated anion exchange membranes (AEMs). The inter-chain π-π stacking between adjacent benzene rings induces directional self-assembly aggregation and enables highly ordered ion-conductive channels. The resulting structure was characterized through UV/VIS spectrum, X-ray diffraction (XRD) pattern, small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and density functional theory (DFT) calculations, leading to high OH− conductivity of 135.5 mS cm−1 at 80 °C. Furthermore, the double bonds in the π-conjugated system also trigger in situ self-crosslinking of the AEMs to enhance dimensional and alkaline stability. Benefiting from this advantage, the as-obtained Cr-QPPV-2.51 AEM exhibits superior alkaline stability (95 % conductivity retention after 3000 hrs in 1 M KOH at 80 °C) and high mechanical strength of 34.8 MPa. Moreover, the fuel cell using Cr-QPPV-2.51 shows a maximum peak power density of 1.27 W cm−2 at 80 °C. 相似文献
996.
Dr. Tiancheng Pu Wenhao Zhang Prof. Minghui Zhu 《Angewandte Chemie (International ed. in English)》2023,62(4):e202212278
Strong metal–support interactions (SMSI) represent a classic yet fast-growing area in catalysis research. The SMSI phenomenon results in the encapsulation and stabilization of metal nanoparticles (NPs) with the support material that significantly impacts the catalytic performance through regulation of the interfacial interactions. Engineering SMSI provides a promising approach to steer catalytic performance in various chemical processes, which serves as an effective tool to tackle energy and environmental challenges. Our Minireview covers characterization, theory, catalytic activity, dependence on the catalytic structure and inducing environment of SMSI phenomena. By providing an overview and outlook on the cutting-edge techniques in this multidisciplinary research field, we not only want to provide insights into the further exploitation of SMSI in catalysis, but we also hope to inspire rational designs and characterization in the broad field of material science and physical chemistry. 相似文献
997.
Constantine Tsounis Dr. Priyank V. Kumar Dr. Hassan Masood Rutvij Pankaj Kulkarni Prof. Gopalakrishnan Sai Gautam Prof. Christoph R. Müller Prof. Rose Amal Dr. Denis A. Kuznetsov 《Angewandte Chemie (International ed. in English)》2023,62(4):e202210828
MXenes, due to their tailorable chemistry and favourable physical properties, have great promise in electrocatalytic energy conversion reactions. To exploit fully their enormous potential, further advances specific to electrocatalysis revolving around their performance, stability, compositional discovery and synthesis are required. The most recent advances in these aspects are discussed in detail: surface functional and stoichiometric modifications which can improve performance, Pourbaix stability related to their electrocatalytic operating conditions, density functional theory and advances in machine learning for their discovery, and prospects in large scale synthesis and solution processing techniques to produce membrane electrode assemblies and integrated electrodes. This Review provides a perspective that is complemented by new density functional theory calculations which show how these recent advances in MXene material design are paving the way for effective electrocatalysts required for the transition to integrated renewable energy systems. 相似文献
998.
Dr. Yusen Li Xi Su Wenhao Zheng Dr. Jia-Jia Zheng Linshuo Guo Prof. Mischa Bonn Prof. Xingfa Gao Dr. Hai I. Wang Prof. Long Chen 《Angewandte Chemie (International ed. in English)》2023,62(10):e202216795
Targeted synthesis of kagome ( kgm ) topologic 2D covalent organic frameworks remains challenging, presumably due to the severe dependence on building units and synthetic conditions. Herein, two isomeric “two-in-one” monomers with different lengths of substituted arms based on naphthalene core (p-Naph and m-Naph) are elaborately designed and utilized for the defined synthesis of isomeric kgm Naph-COFs. The two isomeric frameworks exhibit splendid crystallinity and showcase the same chemical composition and topologic structure with, however, different pore channels. Interestingly, C60 is able to uniformly be encapsulated into the triangle channels of m-Naph-COF via in situ incorporation method, while not the isomeric p-Naph-COF, likely due to the different pore structures of the two isomeric COFs. The resulting stable C60@m-Naph-COF composite exhibits much higher photoconductivity than the m-Naph-COF owing to charge transfer between the conjugated skeletons and C60 guests. 相似文献
999.
Yanan Chang Zhangyu Ma Xuyun Lu Shasha Wang Prof. Jianchun Bao Prof. Ying Liu Prof. Chao Ma 《Angewandte Chemie (International ed. in English)》2023,62(41):e202310163
The rational design of advanced nanohybrids (NHs) with optimized interface electronic environment and rapid reaction kinetics is pivotal to electrocatalytic schedule. Herein, we developed a multiple heterogeneous Co9S8/Co3S4/Cu2S nanoparticle in which Co3S4 germinates between Co9S8 and Cu2S. Using high-angle annular-dark-field imaging and theoretical calculation, it was found that the integration of Co9S8 and Cu2S tends to trigger the interface phase transition of Co9S8, leading to Co3S4 interlayer due to the low formation energy of Co3S4/Cu2S (−7.61 eV) than Co9S8/Cu2S (−5.86 eV). Such phase transition not only lowers the energy barrier of oxygen evolution reaction (OER, from 0.335 eV to 0.297 eV), but also increases charge carrier density (from 7.76×1014 to 2.09×1015 cm−3), and creates more active sites. Compared to Co9S8 and Cu2S, the Co9S8/Co3S4/Cu2S NHs also demonstrate notable photothermal effect that can heat the catalyst locally, offset the endothermic enthalpy change of OER, and promote carrier migrate, reaction intermediates adsorption/deprotonation to improve reaction kinetics. Profiting from these favorable factors, the Co9S8/Co3S4/Cu2S catalyst only requires an OER overpotential of 181 mV and overall water splitting cell voltage of 1.43 V to driven 10 mA cm−2 under the irradiation of near-infrared light, outperforming those without light irradiation and many reported Co-based catalysts. 相似文献
1000.
Seong-Wook Kim Hyeonjung Jung Dr. Mahmut Sait Okyay Dr. Hyuk-Jun Noh Sein Chung Young Hyun Kim Jong-Pil Jeon Prof. Dr. Bryan M. Wong Prof. Dr. Kilwon Cho Dr. Jeong-Min Seo Prof. Dr. Jung-Woo Yoo Prof. Dr. Jong-Beom Baek 《Angewandte Chemie (International ed. in English)》2023,62(42):e202310560
The development of covalent organic frameworks (COFs) with efficient charge transport is of immense interest for applications in optoelectronic devices. To enhance COF charge transport properties, electroactive building blocks and dopants can be used to induce extended conduction channels. However, understanding their intricate interplay remains challenging. We designed and synthesized a tailor-made COF structure with electroactive hexaazatriphenylene (HAT) core units and planar dioxin (D) linkages, denoted as HD-COF. With the support of theoretical calculations, we found that the HAT units in the HD-COF induce strong, eclipsed π–π stacking. The unique stacking of HAT units and the weak in-plane conjugation of dioxin linkages leads to efficient anisotropic charge transport. We fabricated HD-COF films to minimize the grain boundary effect of bulk COFs, which resulted in enhanced conductivity. As a result, the HD-COF films showed an electrical conductivity as high as 1.25 S cm−1 after doping with tris(4-bromophenyl)ammoniumyl hexachloroantimonate. 相似文献