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Science China Chemistry 2024年第4期67卷 1224-1228页

作者： Ming-Ming Gan Zi-En Zhang Yi-Fan Zhang Heng Zhang Li-Ying Sun Ying-Feng Han key laboratory of Synthetic and Natural Functional Molecule Chemistry of the ministry of education Xi’an Key Laboratory of Functional Supramolecular Structure and MaterialsCollege of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China

In this study,we present a supramolecular templating approach for constructing polyimidazolium salt containing crown ether and cyclobutane *** strategy involves the formation of metal-carbene templates,photochemical cycloaddition,and subsequent demetallation of metal *** by the host-guest chemistry between crown ether units and ammonium salts,we successfully fabricated a supramolecular polymer SPN1,which features imidazolium receptors and cyclobutane *** obtained SPN1 demonstrates outstanding reversible stimulus-response,antibacterial behavior and conductivity.

关键词： metal-carbene template crown ether polyimidazolium salt host-guest chemistry

Polymer-to-Monomers Chemically Recyclable Poly(imide-imine)Plastics with Extreme-Condition Resistance and Flame Retardancy

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Chinese Journal of Polymer Science 2024年第10期42卷 1525-1535,I0012页

作者： Zhen-Yu Wang Xiao-Kong Liu State key laboratory of supramolecular structure and materials College of ChemistryJilin UniversityChangchun130012China

Polyimides are a family of high-tech plastics that have irreplaceable applications in the fields of aerospace,defense,and opto-electronics,but polyimides are difficult to be reprocessed and recycled at the end of their service life,resulting in a significant waste of ***,it is of great significance to develop recyclable polyimides with comparable properties to the commercial ***,we report a novel polymer-to-monomers chemically recyclable poly(imide-imine)(PtM-CR-PII)plastic,synthesized by cross-linking the amine-terminated aromatic bisimide monomer and the hexa-vanillin terminated cyclophosphazene monomer via dynamic imine *** PtM-CR-PII plastic exhibits comparable mechanical and thermal properties as well as chemical stability to the commercial *** PtM-CR-PII plastic possesses a high Young’s modulus of≈3.2 GPa and a tensile strength as high as≈108 MPa,which also exhibits high thermal stability with a glass transition temperature of≈220℃.Moreover,the PtM-CR-PII plastic exhibits outstanding waterproofness,acid/alkali-resistance,and solvent-resistance,its appearance and mechanical properties can be well maintained after long-term soaking in water,highly concentrated acid and base,and various organic ***,the cyclophosphazene moieties endow the PtM-CR-PII plastic with excellent flame *** PtM-CR-PII plastic exhibits the highest UL-94 flame-retarding rating of V-0 and a limiting oxygen index(LOI)value of 45.5%.Importantly,the PtM-CR-PII plastic can be depolymerized in an organic solvents-acid mixture medium at room temperature,allowing easy separation and recovery of both monomers in high *** recovered pure monomers can be used to regenerate new PtM-CR-PII plastics,enabling sustainable polymer-monomers-polymer circulation.

关键词： Chemical recyclability Polyimides Polyimines Dynamic imine bonds Mechanical properties Chemical stability

Pd cluster decorated free standing flexible cathode for high performance Li-oxygen batteries

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Nano Research 2024年第4期17卷 2678-2686页

作者： Liang Guo Guoliang Zhang Ruonan Yang Dongmei Zhang Xiuqi Zhang Han Yu Xia Li Feng Dang key laboratory for Liquid-Solid structure Evolution and Processing of materials Ministry of EducationShandong UniversityJinan 250061China

As a promising candidate for the next generation energy storage system,rechargeable lithium-oxygen batteries(LOBs)still face substantial challenges caused by insulating discharge products that preclude their practical *** highly efficient cathode catalysts capable of facilitating formation/decomposition of discharge products is considered as an essential approach towards high performance ***,Pd decorated Te nanowires(Pd@Te NWs)were synthesized as advanced catalyst in LOBs to maximize Pd utilization and achieve synergistic effect,in which Pd clusters were uniformly grown on Te substrate though regulating the Pd:Te ***,Pd@Te nanowires assembled into an interpenetrating network-like structure by vacuum filtration and employed as flexible cathode,enabling LOBs achieved an ultralong 190 cycles stability and a superior specific capacity of 3.35 mAh·cm^(-2).Experimental studies and density functional theory(DFT)calculations reveal the excellent catalytic ability of Pd@Te and synergistic catalytic mechanism of Pd and Te,in which uniform electron distribution,extensive electron exchange,and large adsorption distance between Pd cluster and discharge products promote homogeneous adsorption/desorption of discharge products,while the high adsorption energy of Te substrate for Li species reduces the initial dynamical energy barrier during discharging *** current work provides viable strategy to design composite catalysts for flexible cathode of LOBs with synergistic catalytic effects.

关键词： flexible lithium-oxygen batteries Pd@Te synergistic catalysis cathode catalysts density functional theory(DFT)calculation

Living/controlled polymerization of vinylpyridines into sequence-regulated copolymers by Lewis pair

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Science China Chemistry 2024年第8期67卷 2737-2746页

作者： Qiankun Ding Wuchao Zhao Fukuan Li Jianghua He Yuetao Zhang Department of State key laboratory of supramolecular structure and materials College of ChemistryJilin UniversityChangchun 130012China

The poly(vinylpyridine)(PVP) based(co)polymers are of particular interest in materials science, due to their multifunctionality and diverse applications. So far, there is no report on the sequence-regulated copolymerization of vinylpyridines(VPs) and methacrylate monomer in one-step manner yet. Here we designed and synthesized a series of guanidine phosphines as Lewis base(LB), which is combined with bulky organoaluminium to construct Lewis pairs(LPs) for polymerization of VPs. The living/controlled polymerization of 4-vinylpyridine(4-VP) or 2-vinylpyridine(2-VP) can be accomplished with remarkable efficiency by such Lewis pair polymerization(LPP), furnishing polymers with high molecular weight(up to 288 kg/mol) and narrow molecular weight distribution(as low as 1.17). Mechanistic studies reveal the interaction of LPs and formation of zwitterionic intermediates, providing solid evidences to support the proposed polymerization mechanism. More importantly, by simply adjusting the LA dosage, this LPP strategy realizes the unprecedented control over the sequence regulation of 2-VP-based copolymers from gradient to block in one-step manner, regardless of the monomer ratio, which greatly expands the versatility of the LPP.

关键词： guanidine phosphine Lewis pair polymerization living/controlled polymerization vinyl pyridine sequence regulation

Integrated multi-scale approach combining global homogenization and local refinement for multi-field analysis of high-temperature superconducting composite magnets

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 747-762页

作者： Hanxiao GUO Peifeng GAO Xingzhe WANG key laboratory of Mechanics on Western Disaster and Environment of ministry of education Key Laboratory of Special Function Materials and Structure Design of Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting *** respect to epoxy-impregnated REBCO composite magnets that comprise multilayer components,the thermomechanical characteristics of each component differ considerably under extremely low temperatures and strong electromagnetic *** numerical models include homogenized orthotropic models,which simplify overall field calculation but miss detailed multi-physics aspects,and full refinement(FR)ones that are thorough but computationally ***,we propose an extended multi-scale approach for analyzing the multi-field characteristics of an epoxy-impregnated composite magnet assembled by HTS pancake *** approach combines a global homogenization(GH)scheme based on the homogenized electromagnetic T-A model,a method for solving Maxwell's equations for superconducting materials based on the current vector potential T and the magnetic field vector potential A,and a homogenized orthotropic thermoelastic model to assess the electromagnetic and thermoelastic properties at the macroscopic *** then identify“dangerous regions”at the macroscopic scale and obtain finer details using a local refinement(LR)scheme to capture the responses of each component material in the HTS composite tapes at the mesoscopic *** results of the present GH-LR multi-scale approach agree well with those of the FR scheme and the experimental data in the literature,indicating that the present approach is accurate and *** proposed GH-LR multi-scale approach can serve as a valuable tool for evaluating the risk of failure in large-scale HTS composite magnets.

关键词： epoxy-impregnated high-temperature superconducting(HTS)magnet multi-scale method global homogenization(GH) local refinement(LR) multi-field analysis

A highly reduced Mo_(74) polyoxometalate featuring high proton conductivity accessed by building block strategy

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Science China Chemistry 2024年第3期67卷 862-868页

作者： Shi-Yi Liu Xue-Xin Li Wei-Chao Chen Kui-Zhan Shao Xin-Long Wang Chao Qin Zhong-Min Su key laboratory of Polyoxometalate and Reticular Material Chemistry of ministry of education Department of ChemistryNortheast Normal UniversityChangchun 130024China State key laboratory of supramolecular structure and materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction *** we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton ***,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting *** result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.

关键词： polyoxometalate building block molybdenum highly reduced state proton conduction

A scalable one-pot strategy for the development of polymer electrolytes adaptable to room-temperature high-voltage lithium batteries

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Chinese Chemical Letters 2024年第3期35卷 461-467页

作者： Yue Guo Xinxin Qu Zhen Li Ruiyuan Tian Xiaokong Liu State key laboratory of supramolecular structure and materials College of ChemistryJilin UniversityChangchun 130012China key laboratory of Physics and Technology for Advanced Batteries(ministry of education) College of PhysicsJilin UniversityChangchun 130012China

Poly(ethylene oxide)(PEO)polymer electrolytes(PEs)have been commercially applied in LiFePO_(4)||Li solid-state lithium batteries(SSLBs).However,it remains challenging to develop PEO-based PEs applicable to the high-voltage SSLBs with higher energy density,owing to the poor electrochemical stability of ***,we report a scalable strategy for fabricating PEO-based PEs with high-voltage compatibility,by exploiting a new mechanism to stabilize the cathode-electrolyte interface in the highvoltage *** protocol only involves a one-pot synthesis procedure to covalently crosslink the PEO chains,in the presence of high-content lithium bis(trifluoromethylsulphonyl)imide(LiTFSI)salts and N,N-dimethylformamide(DMF).LiTFSI-DMF supramolecular aggregates are formed and firmly embedded in the polymer network,endowing the PE with high room-temperature ionic *** dissociated and highly concentrated TFSI^-anions can enter the Helmholtz layer close to the high-voltage cathode,leading to the formation of a thin and homogeneous cathode electrolyte interface(CEI),mainly composed of LiF,on the *** CEI with high electrochemical stability can effectively stabilize the cathode-electrolyte interface,enabling long-term stable cycling of the high-voltage LiCoO_(2)||Li and nickelrich NCM_(622)||Li batteries at room *** simplicity and scalability of the strategy makes the reported PEO-based PE potentially applicable in high-voltage SSLBs in practice.

关键词： Lithium batteries Polymer electrolytes Poly(ethylene oxide) Energy density High-voltage cathodes

NHC-derived carbon-centered luminescent radicals with shortwavelength emission via suppression of Kasha's rule

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Science China Chemistry 2024年第8期67卷 2679-2685页

作者： Can Chen Xin Li Xinhua Ouyang Ying-Feng Han key laboratory of Synthetic and Natural Functional Molecule Chemistry of the ministry of education Xi’an Key Laboratory of Functional Supramolecular Structure and MaterialsCollege of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China College of Material Engineering Fujian Agriculture and Forestry University Fuzhou 350108China

Luminescent organic radicals have garnered increasing attention owing to their versatile applications in sensing, imaging, and organic light-emitting diodes(OLEDs), attributed to their unique emission properties originating from the doublet spin ***, the natural narrow bandgap of organic free radicals typically limits their emission to the long-wavelength *** luminescent organic radicals with short-wavelength emission remains a significant challenge. Herein, a series of carbon-centered radicals with short-wavelength emission(383–476 nm) by combining N-heterocyclic carbenes with various polycyclic aromatic hydrocarbons(PAHs)(2-naphthyl, 2a~Ⅰ and 2b~Ⅰ;2-phenanthryl, 2a~Ⅱand 2b~Ⅱ;2-anthryl, 2a~Ⅲand 2b~Ⅲ;3-phenanthryl, 2a~Ⅳand 2b~Ⅳ). Theoretical calculations reveal that the introduction of PAHs significantly increases the ΔE_(D2-D1) in 2a^(Ⅰ–Ⅲ)and 2b^(Ⅰ–Ⅲ)compared to that in phenyl-derived radical congeners. Consequently, the internal transition from D2 to D1 is impeded, leading to a high yield of D2 emission and a suppressed Kasha's rule, thereby overcoming the limitations imposed by their narrow bandgap. For 2a~Ⅳ and 2b~Ⅳ, despite a moderately large ΔED2-D1value, the ΔED3-D1value exceeds 1 e V, indicating that their emission likely originates from the D3 state. Furthermore, we utilized 2a~Ⅲand 2b~Ⅲ as emissive materials in OLEDs,resulting in blue emissions with external quantum efficiencies of 7.5% and 6.5%, respectively.

关键词： N-heterocyclic carbenes luminescent organic molecules carbon-centered radicals short-wavelength emission

High-frequency magnetic properties of biphase Ce_(2)Fe_(17)N_(3)/α-Fe microflakes with easy-plane anisotropy

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Journal of Rare Earths 2024年第1期42卷 110-115,I0004页

作者： Ke Wang Hang Zhang Yuandong Huang Zhibiao Xu Fashen Li Tao Wang key laboratory for Magnetism and Magnetic materials of MOE Lanzhou UniversityLanzhou730000China key laboratory of Special Function materials and structure Design Ministry of EducationLanzhou UniversityLanzhou730000China

Soft magnetic composites(SMCs)are effective as magnetic powder cores in an *** to high saturation magnetization,large magnetocrystalline anisotropy and high operating frequency of M(metal)-RE(rear earth)soft magnetic composites,it is possible to miniaturize inductor cores by reducing total loss,especially eddy current loss and excess loss at high *** this article,the characteristics of Ce_(2)Fe_(17)N_(3)/α-Fe(CFN/F)loss per volume and effective permeability reaching a high frequency of 3 MHz are *** biphase CFN/F composite exhibits a high permeability of 16 at 70 MHz,which is two times greater than that of pure Ce_(2)Fe_(17)N_(3)(CFN)*** total loss is as low as 545 mW/cm^(3)at 3 MHz and 6 *** direct current(DC)-bias properties have a percent of permeability exceeding 65% at H=7960 A/*** phenomenon indicates that our material has a higher working frequency and lower core loss than other materials;the biphase CFN/F structure is a promising and efficient approach for developing the miniaturized radio frequency(RF)inductor core.

关键词： High frequency Soft magnetic composites Easy-plane anisotropy Permeability spectra Core loss Rare earths

Construction of metallo-complexes with 2,2′:6′,2″-terpyridine substituted triphenylamine in different modified positions and their photophysical properties

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Chinese Chemical Letters 2024年第7期35卷 301-305页

作者： Shengwen Guan Zhaotong Wei Ningxu Han Yude Wei Bin Xu Ming Wang Junjuan Shi State key laboratory of supramolecular structure and materials College of ChemistryJilin UniversityChangchun 130012China

The stable coordinated metallo-complexes based on 2,2′:6′,2″-terpyridine(tpy)and its derivatives have been widely researched for various wide-ranging applications in photoelectronics,catalysis,sensor,photoluminescence,and so ***,the most reported studies ignored the comprehensive comparison between structures modified by different positions and ***,we design a series of metallo-complexes which were assembled with tpy substituted triphenylamine(TPA)at different positions and metal ions and explored their photophysical *** the solution state,MLE_(2)based on the 5,5″-positions modification showed the highest PLQYs and PL *** the increase of solvent polarity,MLB2exhibit the largest *** the solid state,from MLA_(2)to MLE_(2),the emission colours are gradually red-shifted from yellow to *** findings in this work may pave a new way to design functional metallo-complexes,not just for PL properties.

关键词： Metallo-complexes 2,2′:6′,2″-terpyridine Triphenylamine Different modified positions Photophysical properties