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Supramolecular synthesis of coumarin derivatives catalyzed by a coordination-assembled cage in aqueous solution

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Science China Chemistry 2019年第6期62卷 713-718页

作者： Shao-Chuan li li-xuan cai li-Peng Zhou Fang Guo Qing-Fu Sun State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences College of Chemistry Liaoning University

A self-assembled Pd_4L_2 cage is employed as a water-soluble molecular flask for the synthesis of functionalized coumarins from a series of salicylaldehyde derivatives and cyanoacetates/malononitrile. The catalytic reaction features mild aqueous conditions and broad substrate scope. Crystal structures of the host-guest complexes for two substrates and one analogous intermediate have been obtained, shedding light on the supramolecular reaction mechanism. Michaelis-Menten kinetic studies were performed in one typical case, revealing that the rate of product formation has been enhanced by over 23-fold in contrast to the background reaction without cage. Moreover, the same reaction catalyzed by a smaller Pd_6L_4 cage gives a mixture of products and much lower yields, suggesting that fine-tuning on the size and symmetry of the cages' cavity is crucial for their applications in supramolecular catalysis.

关键词： coordination-assembly cage encapsulation Knoevenagel condensation

From a mononuclear FeL_(2)complex to a Fe_(4)L_(4)molecular square:Designed assembly and spin-crossover property

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Nano Research 2021年第2期14卷 398-403页

作者： Zhuo Wang li-Peng Zhou li-xuan cai Chong-Bin Tian Qing-Fu Sun State Key Laboratory of Structural Chemisty Fujian Institute of Rssearch on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China

By introduction of a new Fe(L^(1))_(2)spin-crossover(SCO)unit into the polynuclear system,a nano-scale Fe4(L^(2))_(4)molecular square architecture is designed through coordination-directed self-assembly *** the mononuclear Fe(L^(1))_(2)and tetranuclear Fe4(L^(2))_(4)complexes have bee门structurally confirmed by 1H nuclear magnetic resonance(NMR),electrospray ionization time-of-flight mass spectrometry(ESI-TOF-MS),and temperature-dependent single crystal X-ray diffraction ***-temperature magnetic susceptibility measurements reveal the presence of an abrupt SCO behavior with a thermal hysteresis width of 4K for Fe(L^(1))_(2).By clear contrast,Fe4(L^(2))_(4)undergoes a gradual spin transition behavior with enlarged thermal hysteresis width and higher spin transition temperature.

关键词： spin-crossover compound molecular square iron coordination-directed self-assembly supram olecular chem istry

Coordination-Assembled Lanthanide-Organic Ln3L3 Sandwiches or Ln4L4 Tetrahedron: Structural Transformation and Luminescence Modulation

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Chinese Journal of Chemistry 2019年第7期37卷 657-662页

作者： Shao-Jun Hu Xiao-Qing Guo li-Peng Zhou li-xuan cai Qing-Fu Sun State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences FuzhouFujian 350002 China College of Chemistry Fuzhou University Fuzhou Fujian 350108 ChinaState Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences FuzhouFujian 350002 China University of Chinese Academy of Sciences Beijing 100049 ChinaState Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences FuzhouFujian 350002 China

Photo-functional supramolecular lanthanides assemblies have shown great potential in the materials and biomedical *** new tri(tridentate) ligands (L3 and L4) highlighting small variation of the connection position to the central tridentate linkers have been designed,which leads to the emergent formation of either Ln3L3-type sandwich structures or Ln4L4-type tetrahedral ***,nonlinear enhancement of lanthanide luminescence based on the modulation of inter-ligand charge-transfer states has been revealed on the mix-ligand Ln3L3 *** results provide important guidance for structure-design and photoluminescence optimization of supramolecular lanthanide-organic assemblies.

关键词： Structural Transformation Luminescence Modulation

CPL-active hybrid copper(Ⅰ)halides enabled by cation inclusion with chiral crown-ether

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Science China Chemistry 2024年第10期67卷 3283-3290页

作者： Peng Fan li-xuan cai Xiao-Fang Duan Fan Yin Chen-Chen li Zhong-Hua Deng Xiao-Zhen li Qing-Fu Sun College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350117China Strait Institute of Flexible Electronics(Future Technologies) Fujian Key Laboratory of Flexible ElectronicsFujian Normal University and Strait Laboratory of Flexible ElectronicsFuzhou 350117China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian College University of Chinese Academy of SciencesFuzhou 350002China

Chiral hybrid metal halides with high photoluminescence quantum yield(PLQY)and superior dissymmetry factor(g_(lum))are promising candidates for circularly polarized luminescence(CPL)emitting ***,it is a great challenge to achieve both high g_(lum)and large ***,we report a new supramolecular strategy to fabricate chiral hybrid Cu(Ⅰ)-halides with nearunity quantum yields and intense CPL *** dissymmetry factor can be dramatically modulated by tuning the hostguest *** to the chirality and variable conformations of the host-guest complexes,a series of chiral[G@L^(R/S)]_(2)Cu_(4)I_(6)have been *** incorporation of different cations within the chiral L^(R/S)hosts leads to variations of packing modes along the c-axis and different extent of distortions in the[Cu_(4)I_(6)]_(2)-*** them,[H_(3)O@L^(R/S)]+cations are stacked based on Van der Waals interactions and hierarchically self-assemble into a right/left-handed helix in[H_(3)O@L^(R/S)]_(2)Cu_(4)I_(6),which results in a high g_(lum)of-7×10^(-3)and a large PLQY of 96.92%.Notably,[G@L^(R/S)]_(2)Cu_(4)I_(6)shows promising applications in single-component white light emitting diodes(WLEDs),exhibiting a maximum dissymmetry factor of-1.2×10^(-3).The effective host-guest complexation and oriented hierarchical self-assembly provide an effective strategy for the development of high-performance CPL materials.

关键词： host-guest interaction circularly polarized luminescence copper iodide cluster hierarchical self-assembly chirality

Ionic Radius Dependent Kinetic Behavior for the Self-Assemblyand Chiral Amplification of Lanthanide Tetrahedral Cages

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Chinese Journal of Chemistry 2023年第7期41卷 797-804页

作者： Shao-Jun Hu Xiao-Qing Guo li-Peng Zhou li-xuan cai Chong-Bin Tian Qing-Fu Sun State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002 China University of Chinese Academy of Sciences Beijing100049 China

Comprehensive Summary Understanding the kinetic process during the self-assembly and chiral amplification of metal-organic polyhedra(MOPs)is critical for the rational preparation of chiral ***,we report the ionic radius dependent kinetic processes for the self-assembly and chiral amplification of Ln4L4-type(Ln,Lanthanides;L,ligand)lanthanide tetrahedral *** chiral Eu4(LR)4 tetrahedral cage is structurally characterized by nuclear magnetic resonance(NMR),electrospray ionization time-of-flight mass spectrometry(ESI-TOF-MS),and single crystal X-ray *** study on the stereo-controlled self-assembly of circularly polarized luminescence(CPL)-active Ln4(LR)4(Ln=LaIII,PrIII and EuIII)tetrahedra manifests that the larger ionic radius of Ln leads to faster assembly ***-ligand cage assembly experiments with chiral LR/S,achiral Lac and Ln(1:3:4 molar ratio)reveal that the self-assembly and chiral amplification occur synchronously for the LaIII and PrIII cages,while two distinct steps,i.e.,first self-assembly and then chiral amplification,are observed for the EuIII *** distinct kinetic behavior is attributed to different ligands exchange rates among the mixed-ligand Ln4L4 *** work provides fundamental guidance for fabrication and property-optimization of chiral lanthanide-based molecular materials.

关键词： Chiral lanthanide tetrahedron Self-assembly Chiral amplification Kinetic lonic radius

A novel method for simultaneous measurement of^(222)Rn and^(220)Rn progeny concentrations measured by an alpha spectrometer

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Nuclear Science and Techniques 2025年第1期36卷 127-139页

作者： Zhong-Kai Fan Jia-Le Sun Hao-xuan li Xiang-Ming cai Hui Yang Shou-Kang Qiu Yan-liang Tan Jian Shan School of Nuclear Science and Technology University of South ChinaHengyang 421001China College of Physics and Electronic Engineering Hengyang Normal UniversityHengyang 421008China

The accumulation of^(222)Rn and^(220)Rn progeny in poorly ventilated environments poses the risk of natural radiation exposure to the public.A previous study indicated that satisfactory results in determining the^(222)Rn and^(220)Rn progeny concentrations by measuring the total alpha counts at five time intervals within 560 min should be expected only in the case of high progeny concentrations in *** complete the measurement within a relatively short period and adapt it for simultaneous measurements at comparatively lower^(222)Rn and^(220)Rn progeny concentrations,a novel mathematical model was proposed based on the radioactive decay *** model employs a nonlinear fitting method to distinguish nuclides with overlapping spectra by utilizing the alpha particle counts of non-overlapping spectra within consecutive measurement cycles to obtain the concentrations of^(222)Rn and^(220)Rn progeny in *** verification experiments were conducted using an alpha *** experimental results demonstrate that the concentrations of^(222)Rn and^(220)Rn progeny calculated by the new method align more closely with the actual circumstances than those calculated by the total count method,and their relative uncertainties are all within±16%.Furthermore,the measurement time was reduced to 90 min,representing an acceleration of 84%.The improved capability of the new method in distinguishing alpha particles with similar energies emitted from ^(218)Po and^(212)Bi,both approximately 6 MeV,contributed to realizing more accurate *** proposed method has the potential advantage of measuring relatively low concentrations of^(222)Rn and^(220)Rn progeny in air more quickly via air filtration.

关键词： ^(222)Rn ^(220)Rn Progeny concentration Nonlinear fitting method Alpha spectrometer

Formation and evolution of supercritical geofluid

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Science China Earth Sciences 2025年第1期68卷 39-51页

作者： Huaiwei NI Yilin XIAO Xiaolin XIONG Xiandong liU Chunxiao GAO Yi-Xiang CHEN Yunguo li Wan-cai li xuan GUO Yang-Yang WANG Dong-Bo TAN li ZHANG State Key Laboratory of lithospheric and Environmental Coevolution University of Science and Technology of ChinaHefei230026China Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei230026China Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou510640China School of Earth Sciences and Engineering Nanjing UniversityNanjing210023China State Key Lab of Superhard Materials Jilin UniversityChangchun130012China

In this work,we provide a comprehensive review on the formation,evolution,properties,and effects of supercritical *** Earth's interior,enhanced miscibility between H_(2)O and silicate by the addition of special components or by the increase of pressure and temperature gives rise to supercritical geofluid with a significant amount of both H_(2)O and silicate *** formation of supercritical geofluid in magmatic-hydrothermal systems,typified by pegmatite system,is governed by meltfluid critical *** formation of supercritical geofluid in metamorphic systems,typified by subducted slab,is governed by the second critical end *** results suggest that the presence of boron and fluorine in pegmatite system makes it possible to form supercritical geofluid at crustal depths,but the release of supercritical geofluid from subducted slab is withheld until almost 100 km depth.A major presence of both H_(2)O and depolymerized structural units(monomers,dimers,etc.)endows supercritical geofluid with unique physical properties including low density,low elastic moduli,low viscosity,high diffusivity,and high electrical *** geofluid can effectively mobilize a variety of elements even including high field strength elements and heavy rare earth *** chemical signatures of supercritical geofluid can be inherited by metasomatized mantle and mantle-derived melts,and this could give an explanation of the oxidation of arc *** separation of supercritical geofluid through the mechanism of spinodal decomposition leads to formation of a melt *** fluid inclusions recovered from subduction zone rocks and pegmatites are possible relics of supercritical *** geofluid can cause electrical anomaly and low seismic velocity near the top of subducted slab,and can be linked with intermediate-focus *** geofluid may have played a crucial role in the formation of pegmatites and associ

关键词： Supercritical geofluid Miscibility Subduction zone Pegmatite

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Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 39-48页

作者： Peng li Meifeng cai Shengjun Miao Yuan li Yu Wang Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China

Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution *** results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with *** is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and ***,there is no obvious relationship between the rock quality designation(RQD)and *** maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same *** addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.

关键词： overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification

Emerging progress:photochemical transformation of nitroso compounds

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Science China Chemistry 2025年第1期68卷 118-133页

作者： Ze-Le Chen Qiang-Qiang li Armido Studer Jun xuan Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials School of Chemistry&Chemical EngineeringAnhui UniversityHefei 230601China Organisch-Chemisches Institut Universitat MünsterMunster 48149Germany

Nitroso compounds have emerged as highly valuable reaction partners or reagents in organic synthesis due to their rich *** versatile profile of these compounds allows them to function as electrophiles,nucleophiles,diradicals,and radical acceptors in diverse *** recent years,notable progress has been made in harnessing photochemical reactions with nitroso compounds to prepare N,O-containing structures using mild and eco-friendly *** nitroso compounds like nitrosoarenes,acyloxy nitroso compounds,N-nitrosoamines and nitrites have received significant attention for their ability to introduce NO moieties into complex molecules that are otherwise difficult to *** this review,we provide an overview of the recent advancements in the visible light-induced conversion of nitroso compounds,with particular emphasis on their role as bifunctional reagents and acceptors of radicals,carbenes and nitrenes.

关键词： nitroso compounds photochemistry radical reaction carbene transformation nitrosoarenes