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All‐solid‐state sodium batteries, using solid electrolyte and abundant sodium resources, show great promise for safe, low‐cost, and large‐scale energy storage applications. The exploration of novel solid electrolytes is critical for the room temperature operation of all‐solid‐state Na batteries. An ideal solid electrolyte must have high ionic conductivity, hold outstanding chemical and electrochemical stability, and employ low‐cost synthetic methods. Achieving the combination of these properties is a grand challenge for the synthesis of sulfide‐based solid electrolytes. Design of the solid electrolyte Na3SbS4 is described, realizing excellent air stability and an economic synthesis based on hard and soft acid and base (HSAB) theory. This new solid electrolyte also exhibits a remarkably high ionic conductivity of 1 mS cm?1 at 25 °C and ideal compatibility with a metallic sodium anode.  相似文献   

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A series containing the highest nuclearity polyoxoniobate (PONb) nanoclusters, ranging from dimers to tetramers, has been obtained. They include one 114‐nuclear {Li8⊂Nb114O316}, one 81‐nuclear {Li3K⊂Nb81O225}, and one 52‐nuclear {H4Nb52O150}. The Nb nuclearity of these PONbs is remarkably larger than those of all known high‐nuclearity PONbs (≤32). Furthermore, the introduction of 3d Cu2+ ions can lead to the generation of extended inorganic–organic hybrid frameworks built from novel, high‐nuclearity, nanoscale heterometallic PONb building blocks {H3Cu3Nb78O222} or {H3Cu4(en)Nb78O222}. These building blocks also contain the largest number of Nb centers of any heterometallic PONbs reported to date. The synthesis of new‐type PONbs has long been a challenging subject in PONb chemistry.  相似文献   

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Interlocking cages are of great interest due to their fascinating structures and potential applications. However, the interlocking of different cages has not been previously reported. Herein, quadruply interlocked [Cu8] and [Cu18] nanocages have been constructed and structurally characterized in cationic metal–organic framework {[CuICu4II(XN)4(PTA)4(H2O)4]0.5 SO4?5 H2O?EtOH}n ( 1 ). 1 can trap the anionic pollutant CrO42? and the radioactive‐contaminant simulant ReO4? with an uptake capacity of 83.2 and 218 mg g?1, respectively. Catalytic investigations reveal 1 is an efficient heterogeneous catalyst for the enamination of ethyl acetoacetate with aniline and the turnover frequency (TOF) can reach a record value of 4000 h?1. More importantly, 1 represents the first of a catalyst of enamination to exhibit excellent size selectivity on different substrates. The robust catalyst can be reused at least ten times without obvious loss in catalytic activity.  相似文献   

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Solid‐state Li metal battery technology is attractive, owing to the high energy density, long lifespans, and better safety. A key obstacle in this technology is the unstable Li/solid‐state electrolyte (SSE) interface involving electrolyte reduction by Li. Herein we report a novel approach based on the use of a nanocomposite consisting of organic elastomeric salts (LiO‐(CH2O)n‐Li) and inorganic nanoparticle salts (LiF, ‐NSO2‐Li, Li2O), which serve as an interphase to protect Li10GeP2S12 (LGPS), a highly conductive but reducible SSE. The nanocomposite is formed in situ on Li via the electrochemical decomposition of a liquid electrolyte, thus having excellent chemical and electrochemical stability, affinity for Li and LGPS, and limited interfacial resistance. XPS depth profiling and SEM show that the nanocomposite effectively restrained the reduction of LGPS. Stable Li electrodeposition over 3000 h and a 200 cycle life for a full cell were achieved.  相似文献   

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Assembled from [Th48Ni6] nanocages, the first transition‐metal (TM)‐thorium metal–organic framework (MOF, 1 ) has been synthesized and structurally characterized. 1 exhibits high solvent and acid/base stability, and resistance to 400 kGy β irradiation. Notably, 1 captures ReO4? (an analogue of radioactive 99TcO4?, a key species in nuclear wastes) with a maximum capacity of 807 mg g?1, falling among the largest values known to date. Furthermore, 1 can enrich methylene blue (MB) and can also serve as an effective and recyclable catalyst for CO2 fixation with epoxides; there is no significant loss of catalytic activity after 10 cycles. Theoretical studies with nucleus‐independent chemical shifts and natural bond orbital analysis reveal that the [Th6O8] clusters in 1 have a unique stable electronic structure with (d–p)π aromaticity, partially rationalising 1 ′s stability.  相似文献   

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Two‐dimensional (2D) halide perovskites have attracted significant attention due to their compositional flexibility and electronic diversity. Understanding the structure–property relationships in 2D double perovskites is essential for their development for optoelectronic applications. In this work, we observed the emergence of pressure‐induced emission (PIE) at 2.5 GPa with a broad emission band and large Stokes shift from initially nonfluorescent (BA)4AgBiBr8 (BA=CH3(CH2)3NH3+). The emission intensity increased significantly upon further compression up to 8.2 GPa. Moreover, the band gap narrowed from the starting 2.61 eV to 2.19 eV at 25.0 GPa accompanied by a color change from light yellow to dark yellow. Analysis of combined in situ high‐pressure photoluminescence, absorption, and angle‐dispersive X‐ray diffraction data indicates that the observed PIE can be attributed to the emission from self‐trapped excitons. This coincides with [AgBr6]5? and [BiBr6]3? inter‐octahedral tilting which cause a structural phase transition. High‐pressure study on (BA)4AgBiBr8 sheds light on the relationship between the structure and optical properties that may improve the material's potential applications in the fields of pressure sensing, information storage and trademark security.  相似文献   

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New Amido and Imido Bridged Complexes of Copper – Syntheses and Structures of [{Li(OEt2)}2][Cu(NPh2)3], [ClCuN(SnMe3)3], [{CuN(SnMe3)2}4], [Cu16(NH2tBu)12Cl16], [{CuNHtBu}8], [Li(dme)3][Cu6(NHMes)3(NMes)2], [PPh3(C6H4)CuNHMes], [{[Li(dme)][Cu(NHMes)(NHPh)]}2], and [{Li(dme)3}3][Li(dme)2][Cu12(NPh)8] The reactions of stannylated and lithiated amines with coppersalts (halogenides, thiocyanates) lead to amido and imido bridged complexes which contain one to twelve metal atoms. [{Li(OEt2)}2][Cu(NPh2)3] ( 1 ) results from the reaction of CuCl with LiNPh2 in the presence of trimethylphosphine. With N(SnMe3)3, CuCl reacts to the donor‐acceptor complex [ClCuN(SnMe3)3] ( 2 ) that is transformed into the tetrameric complex [{CuN(SnMe3)2}4] ( 3 ) by thermolysis. 3 can also be obtained by the reaction of LiN(SnMe3)2 with Cu(SCN)2. While terminally bound in 1 , the amido ligand is μ2‐bridging between copper atoms in compound 3 . The influence of the alkyl amide's leaving group can be seen from a comparison of the reactivity of Me3SnNHtBu and LiNHtBu, respectively. With Me3SnNHtBu, CuCl2 forms the polymeric compound [Cu16(NH2tBu)12Cl16] ( 4 ) whereas in the case of LiNHtBu with both CuCl and CuSCN, the complex [{CuNHtBu}8] ( 5 ) is obtained. The latter contains two planar Cu4N4‐rings similar to those in 3 . If a mesityl group is introduced at the lithium amide, different products are accessible. Both, CuBr and CuSCN, lead to the formation of [Li(dme)3][Cu6(NHMes)3(NMes)2] ( 6 ) whose anion consists of a prismatic copper core with μ2‐bridging amido and μ3‐bridging imido ligands. In the presence of PPh4Cl, a mixture of Cu(SCN)2 and LiNHMes enables an ortho‐metallation reaction that produces [PPh3(C6H4)CuNHMes] ( 7 ). From the reaction of CuSCN with LiNHMes and LiNHPh either the dimeric complex [{[Li(dme)][Cu(NHMes)(NHPh)]}2] ( 8 ) or the cluster [{Li(dme)3}3][Li(dme)2][Cu12(NPh)8] ( 9 ) results. The anion in 9 exhibits a cubo‐octahedron of copper atoms μ3‐bridged by (NPh)2–‐ligands. The solid state structures of compounds 1 – 9 have been determined by single crystal X‐ray diffraction.  相似文献   

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The stability of luminescent materials is a key factor for the practical application in white light‐emitting diodes (LEDs). Poor chemical stability of narrow‐band green‐emitting RbLi(Li3SiO4)2:Eu2+ (RLSO:Eu2+) phosphor hinders their further commercialization even if they have excellent stability against thermal quenching. Herein, we propose an efficient protection scheme by combining the surface coating of amorphous Al2O3 and hydrophobic modification by octadecyltrimethoxysilane (ODTMS) to construct the moisture‐resistant dual‐shelled RLSO:Eu2+@Al2O3@ODTMS composite. The growth mechanisms of both the Al2O3 inorganic layer and the silane organic layer on the phosphor surface are investigated. The results remarkably improve the water‐stability of this narrow‐band green emitter. The evaluation of the white LED by employing this composite as the green component demonstrates that RLSO:Eu2+@Al2O3@ODTMS is a promising candidate for the high‐performance display backlights, and this dual‐shelled strategy provides an alternative method to improve the moisture‐resistant property of humidity‐sensitive phosphors.  相似文献   

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Syntheses and Crystal Structures of [Cu4(As4Ph4)2(PRR′2)4], [Cu14(AsPh)6(SCN)2(PEt2Ph)8], [Cu14(AsPh)6Cl2(PRR′2)8], [Cu12(AsPh)6(PPh3)6], [Cu10(AsPh)4Cl2(PMe3)8], [Cu12(AsSiMe3)6(PRR′2)6], and [Cu8(AsSiMe3)4(PtBu3)4] (R, R′ = Organic Groups) Through the reaction of CuSCN with AsPh(SiMe3)2 in the presence of tertiary phosphines the compounds [Cu4(As4Ph4)2(PRR′2)4] ( 1 – 3 ) ( 1 : R = R′ = nPr, 2 : R = R′ = Et; 3 : R = Me, R′ = nPr) and [Cu14(AsPh)6(SCN)2(PEt2Ph)8] ( 4 ) can be synthesised. Using CuCl instead of CuSCN results to the cluster complexes [Cu14(AsPh)6Cl2(PRR′2)8] ( 5–6 ) ( 5 : R = R′ = Et; 6 : R = Me, R′ = nPr), [Cu12(AsPh)6(PPh3)6] ( 7 ) and [Cu10(AsPh)4Cl2(PMe3)8] ( 8 ). Through reactions of CuOAc with As(SiMe3)3 in the presence of tertiary phosphines the compounds [Cu12(AsSiMe3)6(PRR′2)6] ( 9 – 11 ) ( 9 : R = R′ = Et; 10 : R = Ph, R′ = Et; 11 : R = Et, R′ = Ph) and [Cu8(AsSiMe3)4(PtBu3)4] ( 12 ) can be obtained. In each case the products were characterised by single‐crystal‐X‐ray‐structure‐analyses. As the main structure element 1 – 3 each have two As4Ph42–‐chains as ligands. In contrast 4 – 12 contain discrete AsR2–ligands.  相似文献   

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This paper describes the ability of a new class of heterocyclic γ‐amino acids named ATCs (4‐amino(methyl)‐1,3‐thiazole‐5‐carboxylic acids) to induce turns when included in a tetrapeptide template. Both hybrid Ac‐Val‐(R or S)‐ATC‐Ile‐Ala‐NH2 sequences were synthesized and their conformations were studied by circular dichroism, NMR spectroscopy, MD simulations, and DFT calculations. It was demonstrated that the ATCs induced highly stable C9 pseudocycles in both compounds promoting a twist turn and a reverse turn conformation depending on their absolute configurations. As a proof of concept, a bioactive analogue of gramicidin S was successfully designed using an ATC building block as a turn inducer. The NMR solution structure of the analogue adopted an antiparallel β‐pleated sheet conformation similar to that of the natural compound. The hybrid α,γ‐cyclopeptide exhibited significant reduced haemotoxicity compared to gramicidin S, while maintaining strong antibacterial activity.  相似文献   

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