The search for new non-centrosymmetric(NCS)crystals with wide energy-gaps(Eg)and strong secondharmonic generation(SHG)responses has become one of the greatest challenges in the mid-and farinfrared(MFIR)nonlinear optic...The search for new non-centrosymmetric(NCS)crystals with wide energy-gaps(Eg)and strong secondharmonic generation(SHG)responses has become one of the greatest challenges in the mid-and farinfrared(MFIR)nonlinear optical(NLO)field.In this work,a novel quaternary NCS material Sr_(5)ZnGa_(6)S_(15)(SZGS),which contains a complex 3D anionic framework and possesses the optical properties required for the MFIR NLO applications,especially the good balance between wide Eg(3.15 eV)and large SHG response(d_(ij)=1.2×AgGaS_(2)),has been discovered for the first time.Moreover,the result of theoretical calculation further indicates that the 3D[ZnGa_(6)S_(15)]^(10−)framework makes definitive contributions to the NLO properties.All these studies demonstrate that SZGS is a promising NLO candidate in the MFIR region.展开更多
The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-cry...The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-crystal diffraction. It belongs to orthorhombic with space group Pccn, a = 20.949(3), b = 17.470(3), c = 20.345(3) Angstrom, V = 7446(2) Angstrom(3), Z = 8, D-c = 1.242 g/cm(3), mu = 1.365 mm(-1), F(000) = 2864, R = 0.0544 and wR = 0.1417. The tin atom is of five-coordination in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions and the resulting structure which contains straight twist large ring channels along the axes of a, b and c is a three-dimensional framework polymer containing two different tin atoms.展开更多
The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of vari-ous types of copper deposit. The rocks were dated using several dating methods. Based on the age data ob-tained b...The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of vari-ous types of copper deposit. The rocks were dated using several dating methods. Based on the age data ob-tained by means of three methods, several aspects are dealt with: (1) the dating results obtained by differentmethods and their geological implications have been compared; (2) a chronotectonic framework has been con-structed by means of these reliable ages, which indicates that the ages of the rocks of the Proterozoic mobilebelt fall in a time span of 2400 to 2000 Ma during which global magmatic records are lacking and reflects theages of important events in the mobile belt; (3) according to the ages of inherited zircons, neodymium modelage of the depleted mantle sources (T_(DM)) and geochemical and geological data, a model of Precambrianchronocrustal structure has been constructed, representing a typical for the North China craton.展开更多
The reaction of Cd（NO_3）_2·4H_2O with 4,4？-dipyridylacetylene（4,4？-DPA） and 2-nitroterephthalic acid（2-NO_2-H_2BDC） in DMF/H_2O mixed solvent has afforded a compound {[Cd（2-NO_2-BDC）（4,4？-DPA）]·...The reaction of Cd（NO_3）_2·4H_2O with 4,4？-dipyridylacetylene（4,4？-DPA） and 2-nitroterephthalic acid（2-NO_2-H_2BDC） in DMF/H_2O mixed solvent has afforded a compound {[Cd（2-NO_2-BDC）（4,4？-DPA）]·（DMF）}_n（1）. Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the monoclinic system, space group P21/n, with a = 12.1488（3）, b = 14.6689（3）, c = 13.1615（3） ？, β = 111.809（3）o, V = 2177.63（9） ？~3, Z = 4, C_（23）H_（18）N_4O_7 Cd, M_r = 574.81, D_c = 1.753 g/cm^3, μ = 8.523 mm^（-1）, F（000） = 1152, the final R = 0.0411 and wR = 0.1064 for 3589 observed reflections with I 〉 2s（I）. In compound 1, the Cd（Ⅱ） ions are linked by the carboxylate groups of 2-NO_2-BDC ligands to give a two-dimensional layered structure based on the centrosymmetric dinuclear Cd_2（COO）_2 units, which are further connected by the 4,4？-DPA ligands to produce a three-dimensional framework with pcu topology. Careful examination revealed that compound 1 is a 2-fold interpenetrating framework. Furthermore, the gas adsorption properties of 1 for N_2 and CO_2 have also been investigated.展开更多
By the reaction of different aromatic dicarboxylic acid with zinc nitrate, three metal-carboxylate frameworks, [Zn3（BDC）3（EtOH）2]（1）, [Zn3（BDC）3（py）2]·2DMF（2）, and [Zn3（NH2-BDC）3（H2O）2]·5DMF...By the reaction of different aromatic dicarboxylic acid with zinc nitrate, three metal-carboxylate frameworks, [Zn3（BDC）3（EtOH）2]（1）, [Zn3（BDC）3（py）2]·2DMF（2）, and [Zn3（NH2-BDC）3（H2O）2]·5DMF（3） which are constructed on the same linear trinuclear Zn3（RCOO）6 secondary building units, have been synthesized and characterized by X-ray diffraction analyses. Structural analyses showed that there are terephthalic acids as ligand linkers to form the hxl topological layer structures for 1 and 2. The introduction of the rigid aromatic ring pyridine in 2 as the terminal co-ligand of Zn3-SBU to instead of the flexible ethanol in 1, will form the layer-pillared supramolecular systems with 2-D crisscross channels, through its π-π stacking interactions. Owing to the steric hindrance of amino groups, 3 was assembled into a three-dimensional porous structure with pcu topology derived from the 2-amino-terephthalic acid as linkers to connect the Zn3-SBUs through a head-to-tail type.展开更多
The synthesis of active electrode materials at room temperature is one of the effective strategies to reduce the fabrication cost of sodium ion batteries(SIBs).Herein,a layered material(Na_(2)[(VO)_(2)(HPO_(4))_(2)C_(...The synthesis of active electrode materials at room temperature is one of the effective strategies to reduce the fabrication cost of sodium ion batteries(SIBs).Herein,a layered material(Na_(2)[(VO)_(2)(HPO_(4))_(2)C_(2)O_(4)]·2H_(2)O,abbreviated as NVPC followingly)with open-framework structures has been successfully prepared at room temperature under ambient conditions and is evaluated as a cathode for SIBs.It is revealed that NVPC cathode can deliver a maximum reversible capacity of ca.70 mAh/g at 10 mA/g,and exhibit superior rate capability and cycling performance:at 50 mA/g,maximum reversible capacity ca.50 m Ah/g with capacity retention of 88.4%over 250 cycles corresponds to only 0.046%capacity decay per cycle;at 100 mA/g,a maximum reversible capacity of 35 mAh/g with capacity retention of60.9%over 500 cycles.This study demonstrates a practical example of a low-cost synthesis of the cathode materials for SIBs.At the same time,the systematic electrochemical research results also show promising prospects for long lifespan low-cost SIBs.展开更多
Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylfor...Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylformamide）. Single-crystal X-ray crystallographic study of compound 1 revealed that Cu（II）ions are linked by ainaàligands forming square grid-like layers, which stack together via multiple hydrogen bonding interactions. The solvent-free framework of 1a displayed considerable porosity（void = 46.5%） with one-dimensional（1D） open channels（4.7 ？ ？ 4.8 ？） functionalized by amino groups.Gas sorption measurements of 1 revealed selective carbon dioxide（CO_2） and acetylene（C_2H_2） adsorption over methane（CH_4） and nitrogen（N_2） at ambient temperature.展开更多
A new water-stable metal-organic framework,[Cu_2（bdc）_2（tpt）_3]·2H_2O（1,H_2 bdc = terephthalic acid,tpt = 2,4,6-tri（4-pyridinyl）-1,3,5-triazine）,has been synthesized and characterized by elemental analysi...A new water-stable metal-organic framework,[Cu_2（bdc）_2（tpt）_3]·2H_2O（1,H_2 bdc = terephthalic acid,tpt = 2,4,6-tri（4-pyridinyl）-1,3,5-triazine）,has been synthesized and characterized by elemental analysis,infrared（IR） spectrum,thermogravimetric analysis（TGA）,powder X-ray diffraction（PXRD） and single-crystal X-ray diffraction. Compund 1 crystalizes in monoclinic,space group C2/c with a = 30.147（5）,b = 11.0548（17）,c = 20.867（4） ？,β = 115.035（2）o,C_（70）H_（48）Cu_2N_（18）O_（10）,Mr = 1428.34,V = 6301.0（18） ？~3,Z = 8,D_c = 1.506 g/cm^3,μ = 0.754 mm^（–1）,F（000） = 2928,GOOF = 1.058,λ（MoK α） = 0.71073 ？,the final R = 0.0387 and wR = 0.1091 for 6230 observed reflections with I 〉 2σ（I）. In compound 1,the half metallacycles [Cu_2（tpt）_3] are linked by the bdc2-ligands to form a 1D bent ladder-like chain featured with a nano-sized channel,and these chains link each other via intermolecular hydrogen bonds and π-π stacking interactions to form a 3D supramolecular architecture with the voids filled with free water molecules. In addition,the water stability of 1 was investigated by PXRD patterns,which indicate that compound 1 keeps its structural integrity in boiling water for at least three days.展开更多
A novel two-dimensional metal organic coordination compound based on flexible 1,3,5-tri（4-carboxyphenoxy）benzene （HaTCPB）, {[Mgl.5（TCPB）（DMF）（H20）]＇（DMF）}n （1）, has been prepared and structurally charac...A novel two-dimensional metal organic coordination compound based on flexible 1,3,5-tri（4-carboxyphenoxy）benzene （HaTCPB）, {[Mgl.5（TCPB）（DMF）（H20）]＇（DMF）}n （1）, has been prepared and structurally characterized by single-crystal X-ray diffraction, TGA, and PXRD measurements. Complex 1 crystalizes in triclinic, space group Pi with a = 10.2521（6）, b = 11.0974（7）, c = 16.1113（9） A, C33H31Mg1.5N2012, Mr = 684.06, V= 1669.46（17） A3, Z = 2, Dc = 1.361 g·cm^-3, p = 0.129 mm^-1, F（000） = 714, 3.06≤0≤25°, λ（MoKa） = 0.71073 A, T= 273（2） K, the final R = 0.0386, wR = 0.0892 and S = 1.031. X-ray diffraction analysis reveals that complex 1 possesses a two-dimensional framework constructed by trinuclear Mg SBUs and three-connected TCPB3- linker. In addition, the solid state luminescent property of complex 1 was also investigated at room temperature.展开更多
The octahedral chalcocyanide cluster anion[Re_(6)S_(8)(CN)_(6)]^(4-)can serve as a metallolinker for the self-assembly of metal-organic frameworks(MOFs)comprising polynuclear lanthanide complexes,which have been illus...The octahedral chalcocyanide cluster anion[Re_(6)S_(8)(CN)_(6)]^(4-)can serve as a metallolinker for the self-assembly of metal-organic frameworks(MOFs)comprising polynuclear lanthanide complexes,which have been illustrated for a series of nine compounds isolated as[{Ln_(4)(μ_(3)-OH)_(4)(ina)_(4)(H_(2)O)n}{Re_(6)S_(8)(CN)_(6)}]·mH_(2)O(Ln=Pr-Er,ina=isonicotinate).Their solid-state framework structures are based on{Ln_(4)(μ_(3)-OH)_(4)}^(8+)cubane fragments interlinked by isonicotinate and rhenium cyanide clusters.The coordination environment of the lanthanide ions,the coordination numbers and even the number of bridging isonicotinate moieties changes systematically within the lanthanide row,however,the framework topology remains unchanged,confirming the structure-directing role of the rhenium cluster.Structures,magnetochemical properties,luminescence and thermal stability of the new MOFs have been thoroughly analyzed.展开更多
The theoretical specific energy of lithium-air battery is as high as 3436 Wh.kg^-1, and the possible achieved value may reach 600-700 Wh.kg^-l, which enables this energy storage system as an important propulsion power...The theoretical specific energy of lithium-air battery is as high as 3436 Wh.kg^-1, and the possible achieved value may reach 600-700 Wh.kg^-l, which enables this energy storage system as an important propulsion power sources for electric vehicles with the driving range of 500-800 km. Currently, Li-air batteries are facing main challenges at stability, efficiency, applicability and safety. In particular, from a practical view of point, the Li-air batteries should be operated directly in ambient air. Solid-state battery system is the best avenue to eventually solve these main issues. At the heart of the solid state, Li-air technology is the solid-state Li^＋-conducting ceramic material. Developing solid-state lithium-air batteries （SSLAB） can solve the problem of applicability fundamentally and circumvent the safety issues completely, and it is also an important avenue to improve the stability of the battery system. In this paper, we provide a systematical review of the progress in the cell construction, the regulation of the electrode/electrolyte interface, the cell assembly, the electrochemical performance and the mechanism for the SSLAB. In every section, the contributions of the recent research progress in the main challenges and the remained questions will be commented. Based on these reviews, we attempt to propose some alternative approaches for the next stage and suggest a development prospective for the SSLAB.展开更多
Selective hydrogenation of C=O group that is conjugated with a C=C group in a,b-unsaturated aldehydes(R–CH=CH–CHO)is one of important reactions in industry due to the resulting product unsaturated alcohols(R–CH=CH...Selective hydrogenation of C=O group that is conjugated with a C=C group in a,b-unsaturated aldehydes(R–CH=CH–CHO)is one of important reactions in industry due to the resulting product unsaturated alcohols(R–CH=CH–CH2OH)with broad applications in synthesis of fine chemicals such as flavour,fragrance,pharmaceuticals[1].However,despite the increasing reported catalysts on the selectivity[2,3],developing an effective展开更多
Zeolites have many uses and are continually developed for catalysis and separations as highly active,selective and thermally stable materials with microporous framework structures of various topologies.Among approxima...Zeolites have many uses and are continually developed for catalysis and separations as highly active,selective and thermally stable materials with microporous framework structures of various topologies.Among approximately 250 known frameworks about 20,but possibly all eventually,produced 2D forms with layers of thickness up to a few nanometers.Recently,layered forms of the zeolite MWWand a ferrierite-related one have been exfoliated directly by a soft-chemical treatment into solutions of unilamellar nanosheets.They enable the synthesis of layer-based hierarchical and nanocomposite materials with diverse compositions that are unfeasible with solid 3D and 2D forms.The efficiency and yield of zeolite exfoliation can be inhibited by intergrowth so each topology presents a separate challenge.The MFI zeolite can provide particular benefits as one of the most active and versatile frameworks.It has permeable layers due to perpendicular channels and has been used as a membrane.This article describes exfoliation of the layered MFI produced by the bifunctional template developed by Ryoo et al.It affords unilamellar MFI nanosheets in solution with a uniform hydrated thickness of 3.6 nm confirmed by AFM,X-ray diffraction and TEM.The nanosheets can be reassembled top-down into self-standing b-oriented discs or films,proven by X-ray powder diffraction.They preserve high acid site concentration and porosity.The basal spacing contracts from 3.6 nm to 2.8 nm upon calcination.Oriented MFI films were also formed by the evaporation/calcination of nanosheet solutions and surfactant composites enabling simple fabrication on various substrates for application in catalysis and separations.展开更多
SAPO-14(AFN topology)zeolite has been considered as an ideal catalyst for the methanol-to-propylene(MTP)reaction with a very high one-pass propylene selectivity,due to its unique framework structure containing narrow ...SAPO-14(AFN topology)zeolite has been considered as an ideal catalyst for the methanol-to-propylene(MTP)reaction with a very high one-pass propylene selectivity,due to its unique framework structure containing narrow 8-MR pore openings and ultra-small AFN cages.However,the conventional synthesis of SAPO-14 by hydrothermal treatments generally suffers from issues relating to low-efficiency,difficulty in product collection,and being unfriendly to the environment.Herein,we showcase a facile strategy for the fast and efficient synthesis of highly crystalline SAPO-14 via dry-gel conversion(DGC)for the first time.The crystallization time can be shortened from 2 days to 8 hours at a lower temperature,and the product yield after 8-hour synthesis can be increased from 41.8 to 71.6%compared with the conventional hydrothermal synthesis.Influencing factors in the synthesis,including the molar ratio of dry gel,the time of crystallization,and the ratio of water-to-dry gel(WTDG),on the crystallinity,morphology,and textural properties of the product zeolites are systematically discussed,and the possible crystallization mechanism is also proposed.Successful attempts using four types of silica sources,including silicic acid,fumed silica,Ludox HS-40,and TEOS,confirm the flexibility and adaptability of the proposed synthesis strategy.The superior catalytic performance with not only a high propylene selectivity(76.2%)but also a large P/E ratio(7.19)demonstrates that the SAPO-14 produced by the DGC method is a high-performance catalyst candidate for the selective conversion of methanol to propylene.展开更多
Five isostructural lanthanide metal–organic frameworks [Ln(BDPO)(H_(2)O)_(4)] (Ln = Eu for CUST-623, Tb for CUST-624, Gd for CUST-625, Dy for CUST-626, and Sm for CUST-627, BDPO = N,N'-bis(3,5-dicarboxyphenyl)-ox...Five isostructural lanthanide metal–organic frameworks [Ln(BDPO)(H_(2)O)_(4)] (Ln = Eu for CUST-623, Tb for CUST-624, Gd for CUST-625, Dy for CUST-626, and Sm for CUST-627, BDPO = N,N'-bis(3,5-dicarboxyphenyl)-oxalamide) were synthesized by the solvothermal method. Single-crystal X-ray diffraction shows that Ln-MOFs manifest framework structures with two kinds of 1D open channels in the b-axis direction. Dual emission luminescent thermometer films were successfully prepared by immobilizing Eu_(x)Tb_(0.02−x)-BDPO into polyvinyl alcohol (PVA) aqueous solution, which features the integrity of MOF powders, proving their excellent processability. Moreover, Eu0.002Tb0.018-BDPO@PVA shows excellent temperature sensing performance with a high sensitivity of 3.7% K^(−1) in the temperature range of 303 K–423 K. CUST-623 and CUST-624 can be used as multiresponse fluorescent sensors for detecting Fe^(3+), Cr_(2)O_(7)^(2−), CrO_(4)^(2−) and TNP. In addition, the mechanism of fluorescence sensing is investigated by infrared (IR) spectroscopy, powder X-ray diffraction (PXRD) and ultraviolet–visible (UV-vis) spectroscopy. This work provides a general method for constructing Ln-MOF sensor materials with multifunctional luminescence characteristics.展开更多
Negative thermal expansion(NTE)has both scientific and application value as a novel physical behavior,but the types of NTE materials are still limited.In the present work,a framework structure material,metal dicyanami...Negative thermal expansion(NTE)has both scientific and application value as a novel physical behavior,but the types of NTE materials are still limited.In the present work,a framework structure material,metal dicyanamide Zn[N(CN)_(2)]_(2),has been found to show biaxial negative thermal expansion in a wide temperature range(α_(a)=−11.82×10^(−6)K^(−1),α_(b)=−11.75×10^(−6)K^(−1)from 173 K–473 K).Through a joint study of variable temperature X-ray diffraction,extended X-ray absorption fine structure,Raman spectroscopy,and the maximum entropy method,the NTE mechanisms in Zn[N(CN)_(2)]_(2)have been revealed.The pronounced transverse vibration of C atoms in the multiatomic bridge linkage–N≡C–N–and the rotation of ZnN_(4)tetrahedra play a key role in biaxial negative thermal expansion.This work provides a new class of potential framework structure NTE materials.展开更多
The ligand 2,6,2’,6’-tetranitro-biphenyl-4,4’-dicarboxylic acid(H2L)reacts solvothermally with[Gd(NO_(3))_(3)]·6H_(2)O to produce a flexible and porous metal–organic framework,{[Gd_(2)(L)_(3)(DMF)_(4)]·(...The ligand 2,6,2’,6’-tetranitro-biphenyl-4,4’-dicarboxylic acid(H2L)reacts solvothermally with[Gd(NO_(3))_(3)]·6H_(2)O to produce a flexible and porous metal–organic framework,{[Gd_(2)(L)_(3)(DMF)_(4)]·(4DMF)·(3H_(2)O)}_(n)(1)(DMF=N,N’-dimethylformamide).An X-ray crystallographic study reveals that compound 1 contains a 3D framework structure with two different 1D channels(A and B)that are occupied by solvent DMF and water molecules.展开更多
Three new potassium rare earth carbonates,namely KRE(CO_(3))_(2)(RE=Eu,Gd,Tb),were synthesized successfully.Their structures feature a novel[RE(CO_(3))_(2)]-3D framework with 1D channels along the c axis filled with K...Three new potassium rare earth carbonates,namely KRE(CO_(3))_(2)(RE=Eu,Gd,Tb),were synthesized successfully.Their structures feature a novel[RE(CO_(3))_(2)]-3D framework with 1D channels along the c axis filled with K+cations.Among them,KEu(CO_(3))_(2) and KTb(CO_(3))_(2) emit strong red and green photoluminescence,respectively.The birefringence values of KRE(CO_(3))_(2) were measured as 0.149,0.162 and 0.215 at 546 nm,respectively.Remarkably,KTb(CO_(3))_(2) has the largest experimental birefringence among carbonates reported.展开更多
The demand to increase energy density of rechargeable batteries for portable electronic devices and electric vehicles and to reduce the cost for grid-scale energy storage necessitates the exploration of new chemistrie...The demand to increase energy density of rechargeable batteries for portable electronic devices and electric vehicles and to reduce the cost for grid-scale energy storage necessitates the exploration of new chemistries of electrode materials for rechargeable batteries.The open framework-structure of Prussian-blue materials has recently been demonstrated as a promising cathode host for a variety of monovalent and multivalent cations with the tunable working voltage and discharge capacities.Recent progress toward the application of Prussian-blue cathode materials for rechargeable batteries is reviewed,with special emphasis on charge-storage mechanisms of different insertion species,factors influencing electrochemical performances,and possible approaches to overcome their intrinsic limitations.展开更多
基金supported by the National Natural Science Foundation of China(21771179,21571020 and 21301175)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20010200)the support from“Chunmiao Projects”of Haixi Institute of Chinese Academy of Sciences.
文摘The search for new non-centrosymmetric(NCS)crystals with wide energy-gaps(Eg)and strong secondharmonic generation(SHG)responses has become one of the greatest challenges in the mid-and farinfrared(MFIR)nonlinear optical(NLO)field.In this work,a novel quaternary NCS material Sr_(5)ZnGa_(6)S_(15)(SZGS),which contains a complex 3D anionic framework and possesses the optical properties required for the MFIR NLO applications,especially the good balance between wide Eg(3.15 eV)and large SHG response(d_(ij)=1.2×AgGaS_(2)),has been discovered for the first time.Moreover,the result of theoretical calculation further indicates that the 3D[ZnGa_(6)S_(15)]^(10−)framework makes definitive contributions to the NLO properties.All these studies demonstrate that SZGS is a promising NLO candidate in the MFIR region.
基金the National Natural Science Foundation of China (No. 20271025)the Natural Science Foundation of Shandong province (No. Z2001B02)the State Key Laboratory of Crystal Materials,Shandong University
文摘The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-crystal diffraction. It belongs to orthorhombic with space group Pccn, a = 20.949(3), b = 17.470(3), c = 20.345(3) Angstrom, V = 7446(2) Angstrom(3), Z = 8, D-c = 1.242 g/cm(3), mu = 1.365 mm(-1), F(000) = 2864, R = 0.0544 and wR = 0.1417. The tin atom is of five-coordination in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions and the resulting structure which contains straight twist large ring channels along the axes of a, b and c is a three-dimensional framework polymer containing two different tin atoms.
文摘The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of vari-ous types of copper deposit. The rocks were dated using several dating methods. Based on the age data ob-tained by means of three methods, several aspects are dealt with: (1) the dating results obtained by differentmethods and their geological implications have been compared; (2) a chronotectonic framework has been con-structed by means of these reliable ages, which indicates that the ages of the rocks of the Proterozoic mobilebelt fall in a time span of 2400 to 2000 Ma during which global magmatic records are lacking and reflects theages of important events in the mobile belt; (3) according to the ages of inherited zircons, neodymium modelage of the depleted mantle sources (T_(DM)) and geochemical and geological data, a model of Precambrianchronocrustal structure has been constructed, representing a typical for the North China craton.
基金Supported by the National Natural Science Foundation of China(No.21361011 and 21101081)the Natural Science Foundation of Jiangxi Province(No.20151BAB203002)
文摘The reaction of Cd（NO_3）_2·4H_2O with 4,4？-dipyridylacetylene（4,4？-DPA） and 2-nitroterephthalic acid（2-NO_2-H_2BDC） in DMF/H_2O mixed solvent has afforded a compound {[Cd（2-NO_2-BDC）（4,4？-DPA）]·（DMF）}_n（1）. Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the monoclinic system, space group P21/n, with a = 12.1488（3）, b = 14.6689（3）, c = 13.1615（3） ？, β = 111.809（3）o, V = 2177.63（9） ？~3, Z = 4, C_（23）H_（18）N_4O_7 Cd, M_r = 574.81, D_c = 1.753 g/cm^3, μ = 8.523 mm^（-1）, F（000） = 1152, the final R = 0.0411 and wR = 0.1064 for 3589 observed reflections with I 〉 2s（I）. In compound 1, the Cd（Ⅱ） ions are linked by the carboxylate groups of 2-NO_2-BDC ligands to give a two-dimensional layered structure based on the centrosymmetric dinuclear Cd_2（COO）_2 units, which are further connected by the 4,4？-DPA ligands to produce a three-dimensional framework with pcu topology. Careful examination revealed that compound 1 is a 2-fold interpenetrating framework. Furthermore, the gas adsorption properties of 1 for N_2 and CO_2 have also been investigated.
基金supported by the National Natural Science Foundation of China(No.11375082,11305086,11175080)Science Foundation of Hunan Province Department of Education(No.12A117)the Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(Wang X.F.)
文摘By the reaction of different aromatic dicarboxylic acid with zinc nitrate, three metal-carboxylate frameworks, [Zn3（BDC）3（EtOH）2]（1）, [Zn3（BDC）3（py）2]·2DMF（2）, and [Zn3（NH2-BDC）3（H2O）2]·5DMF（3） which are constructed on the same linear trinuclear Zn3（RCOO）6 secondary building units, have been synthesized and characterized by X-ray diffraction analyses. Structural analyses showed that there are terephthalic acids as ligand linkers to form the hxl topological layer structures for 1 and 2. The introduction of the rigid aromatic ring pyridine in 2 as the terminal co-ligand of Zn3-SBU to instead of the flexible ethanol in 1, will form the layer-pillared supramolecular systems with 2-D crisscross channels, through its π-π stacking interactions. Owing to the steric hindrance of amino groups, 3 was assembled into a three-dimensional porous structure with pcu topology derived from the 2-amino-terephthalic acid as linkers to connect the Zn3-SBUs through a head-to-tail type.
基金financially supported by the National Natural Science Foundation of China(No.21805278)。
文摘The synthesis of active electrode materials at room temperature is one of the effective strategies to reduce the fabrication cost of sodium ion batteries(SIBs).Herein,a layered material(Na_(2)[(VO)_(2)(HPO_(4))_(2)C_(2)O_(4)]·2H_(2)O,abbreviated as NVPC followingly)with open-framework structures has been successfully prepared at room temperature under ambient conditions and is evaluated as a cathode for SIBs.It is revealed that NVPC cathode can deliver a maximum reversible capacity of ca.70 mAh/g at 10 mA/g,and exhibit superior rate capability and cycling performance:at 50 mA/g,maximum reversible capacity ca.50 m Ah/g with capacity retention of 88.4%over 250 cycles corresponds to only 0.046%capacity decay per cycle;at 100 mA/g,a maximum reversible capacity of 35 mAh/g with capacity retention of60.9%over 500 cycles.This study demonstrates a practical example of a low-cost synthesis of the cathode materials for SIBs.At the same time,the systematic electrochemical research results also show promising prospects for long lifespan low-cost SIBs.
基金supported by the grant AX-1593(JCGZ)and AX1730(BC)from the Welch Foundation
文摘Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylformamide）. Single-crystal X-ray crystallographic study of compound 1 revealed that Cu（II）ions are linked by ainaàligands forming square grid-like layers, which stack together via multiple hydrogen bonding interactions. The solvent-free framework of 1a displayed considerable porosity（void = 46.5%） with one-dimensional（1D） open channels（4.7 ？ ？ 4.8 ？） functionalized by amino groups.Gas sorption measurements of 1 revealed selective carbon dioxide（CO_2） and acetylene（C_2H_2） adsorption over methane（CH_4） and nitrogen（N_2） at ambient temperature.
基金supported by the 973 key program of the Chinese Ministry of Science and Technology(MOST)(2012CB821705)
文摘A new water-stable metal-organic framework,[Cu_2（bdc）_2（tpt）_3]·2H_2O（1,H_2 bdc = terephthalic acid,tpt = 2,4,6-tri（4-pyridinyl）-1,3,5-triazine）,has been synthesized and characterized by elemental analysis,infrared（IR） spectrum,thermogravimetric analysis（TGA）,powder X-ray diffraction（PXRD） and single-crystal X-ray diffraction. Compund 1 crystalizes in monoclinic,space group C2/c with a = 30.147（5）,b = 11.0548（17）,c = 20.867（4） ？,β = 115.035（2）o,C_（70）H_（48）Cu_2N_（18）O_（10）,Mr = 1428.34,V = 6301.0（18） ？~3,Z = 8,D_c = 1.506 g/cm^3,μ = 0.754 mm^（–1）,F（000） = 2928,GOOF = 1.058,λ（MoK α） = 0.71073 ？,the final R = 0.0387 and wR = 0.1091 for 6230 observed reflections with I 〉 2σ（I）. In compound 1,the half metallacycles [Cu_2（tpt）_3] are linked by the bdc2-ligands to form a 1D bent ladder-like chain featured with a nano-sized channel,and these chains link each other via intermolecular hydrogen bonds and π-π stacking interactions to form a 3D supramolecular architecture with the voids filled with free water molecules. In addition,the water stability of 1 was investigated by PXRD patterns,which indicate that compound 1 keeps its structural integrity in boiling water for at least three days.
基金Supported by the National Natural Science Foundation of China(No.21371179)
文摘A novel two-dimensional metal organic coordination compound based on flexible 1,3,5-tri（4-carboxyphenoxy）benzene （HaTCPB）, {[Mgl.5（TCPB）（DMF）（H20）]＇（DMF）}n （1）, has been prepared and structurally characterized by single-crystal X-ray diffraction, TGA, and PXRD measurements. Complex 1 crystalizes in triclinic, space group Pi with a = 10.2521（6）, b = 11.0974（7）, c = 16.1113（9） A, C33H31Mg1.5N2012, Mr = 684.06, V= 1669.46（17） A3, Z = 2, Dc = 1.361 g·cm^-3, p = 0.129 mm^-1, F（000） = 714, 3.06≤0≤25°, λ（MoKa） = 0.71073 A, T= 273（2） K, the final R = 0.0386, wR = 0.0892 and S = 1.031. X-ray diffraction analysis reveals that complex 1 possesses a two-dimensional framework constructed by trinuclear Mg SBUs and three-connected TCPB3- linker. In addition, the solid state luminescent property of complex 1 was also investigated at room temperature.
文摘The octahedral chalcocyanide cluster anion[Re_(6)S_(8)(CN)_(6)]^(4-)can serve as a metallolinker for the self-assembly of metal-organic frameworks(MOFs)comprising polynuclear lanthanide complexes,which have been illustrated for a series of nine compounds isolated as[{Ln_(4)(μ_(3)-OH)_(4)(ina)_(4)(H_(2)O)n}{Re_(6)S_(8)(CN)_(6)}]·mH_(2)O(Ln=Pr-Er,ina=isonicotinate).Their solid-state framework structures are based on{Ln_(4)(μ_(3)-OH)_(4)}^(8+)cubane fragments interlinked by isonicotinate and rhenium cyanide clusters.The coordination environment of the lanthanide ions,the coordination numbers and even the number of bridging isonicotinate moieties changes systematically within the lanthanide row,however,the framework topology remains unchanged,confirming the structure-directing role of the rhenium cluster.Structures,magnetochemical properties,luminescence and thermal stability of the new MOFs have been thoroughly analyzed.
基金financially supported by the ‘‘Hundred Talents’’ program of the Chinese Academy of Sciences(2015)‘‘The Recruitment Program of Global Experts’’ in Shanghai(2016)the National Natural Science Foundation of China(Nos.51672299 and 51772314)
文摘The theoretical specific energy of lithium-air battery is as high as 3436 Wh.kg^-1, and the possible achieved value may reach 600-700 Wh.kg^-l, which enables this energy storage system as an important propulsion power sources for electric vehicles with the driving range of 500-800 km. Currently, Li-air batteries are facing main challenges at stability, efficiency, applicability and safety. In particular, from a practical view of point, the Li-air batteries should be operated directly in ambient air. Solid-state battery system is the best avenue to eventually solve these main issues. At the heart of the solid state, Li-air technology is the solid-state Li^＋-conducting ceramic material. Developing solid-state lithium-air batteries （SSLAB） can solve the problem of applicability fundamentally and circumvent the safety issues completely, and it is also an important avenue to improve the stability of the battery system. In this paper, we provide a systematical review of the progress in the cell construction, the regulation of the electrode/electrolyte interface, the cell assembly, the electrochemical performance and the mechanism for the SSLAB. In every section, the contributions of the recent research progress in the main challenges and the remained questions will be commented. Based on these reviews, we attempt to propose some alternative approaches for the next stage and suggest a development prospective for the SSLAB.
文摘Selective hydrogenation of C=O group that is conjugated with a C=C group in a,b-unsaturated aldehydes(R–CH=CH–CHO)is one of important reactions in industry due to the resulting product unsaturated alcohols(R–CH=CH–CH2OH)with broad applications in synthesis of fine chemicals such as flavour,fragrance,pharmaceuticals[1].However,despite the increasing reported catalysts on the selectivity[2,3],developing an effective
基金financed with the funds from the National Science Centre Poland,grant no 2020/37/B/ST5/01258(WJR,BG)The in-plane XRD measurements were performed under the approval of the Photon Factory Program Advisory Committee(Proposal No.2020G503)+3 种基金the Czech Science Foundation for funding this research through the ExPro project(19-27551X)OP VVV“Excellent Research Teams”,project no.CZ.02.1.01/0.0/0.0/15_003/0000417-CUCAMthe Japan Science and Technology Agency(JST),Grant No.JPMJCR17N1(CREST)the Japan Society for the Promotion of Science(JSPS),Grant No.P21036。
文摘Zeolites have many uses and are continually developed for catalysis and separations as highly active,selective and thermally stable materials with microporous framework structures of various topologies.Among approximately 250 known frameworks about 20,but possibly all eventually,produced 2D forms with layers of thickness up to a few nanometers.Recently,layered forms of the zeolite MWWand a ferrierite-related one have been exfoliated directly by a soft-chemical treatment into solutions of unilamellar nanosheets.They enable the synthesis of layer-based hierarchical and nanocomposite materials with diverse compositions that are unfeasible with solid 3D and 2D forms.The efficiency and yield of zeolite exfoliation can be inhibited by intergrowth so each topology presents a separate challenge.The MFI zeolite can provide particular benefits as one of the most active and versatile frameworks.It has permeable layers due to perpendicular channels and has been used as a membrane.This article describes exfoliation of the layered MFI produced by the bifunctional template developed by Ryoo et al.It affords unilamellar MFI nanosheets in solution with a uniform hydrated thickness of 3.6 nm confirmed by AFM,X-ray diffraction and TEM.The nanosheets can be reassembled top-down into self-standing b-oriented discs or films,proven by X-ray powder diffraction.They preserve high acid site concentration and porosity.The basal spacing contracts from 3.6 nm to 2.8 nm upon calcination.Oriented MFI films were also formed by the evaporation/calcination of nanosheet solutions and surfactant composites enabling simple fabrication on various substrates for application in catalysis and separations.
基金financed by a project supported by the National Natural Science Foundation of China(21978238)Natural Science Foundation of Shaanxi Provincial Department of Education(21JY041).
文摘SAPO-14(AFN topology)zeolite has been considered as an ideal catalyst for the methanol-to-propylene(MTP)reaction with a very high one-pass propylene selectivity,due to its unique framework structure containing narrow 8-MR pore openings and ultra-small AFN cages.However,the conventional synthesis of SAPO-14 by hydrothermal treatments generally suffers from issues relating to low-efficiency,difficulty in product collection,and being unfriendly to the environment.Herein,we showcase a facile strategy for the fast and efficient synthesis of highly crystalline SAPO-14 via dry-gel conversion(DGC)for the first time.The crystallization time can be shortened from 2 days to 8 hours at a lower temperature,and the product yield after 8-hour synthesis can be increased from 41.8 to 71.6%compared with the conventional hydrothermal synthesis.Influencing factors in the synthesis,including the molar ratio of dry gel,the time of crystallization,and the ratio of water-to-dry gel(WTDG),on the crystallinity,morphology,and textural properties of the product zeolites are systematically discussed,and the possible crystallization mechanism is also proposed.Successful attempts using four types of silica sources,including silicic acid,fumed silica,Ludox HS-40,and TEOS,confirm the flexibility and adaptability of the proposed synthesis strategy.The superior catalytic performance with not only a high propylene selectivity(76.2%)but also a large P/E ratio(7.19)demonstrates that the SAPO-14 produced by the DGC method is a high-performance catalyst candidate for the selective conversion of methanol to propylene.
基金supported by the Joint Fund Project of the Natural Science Foundation of Jilin Province(YDZJ202101ZYTS052)the Open Project Program of Key Laboratory of Preparation and Application of Environmental Friendly Materials(Jilin Normal University)+1 种基金Ministry of Education,China(No.2021008)the Foundation of Changchun University of Science and Technology(XQNJJ-2019-12 and XJJLG-2019-03).
文摘Five isostructural lanthanide metal–organic frameworks [Ln(BDPO)(H_(2)O)_(4)] (Ln = Eu for CUST-623, Tb for CUST-624, Gd for CUST-625, Dy for CUST-626, and Sm for CUST-627, BDPO = N,N'-bis(3,5-dicarboxyphenyl)-oxalamide) were synthesized by the solvothermal method. Single-crystal X-ray diffraction shows that Ln-MOFs manifest framework structures with two kinds of 1D open channels in the b-axis direction. Dual emission luminescent thermometer films were successfully prepared by immobilizing Eu_(x)Tb_(0.02−x)-BDPO into polyvinyl alcohol (PVA) aqueous solution, which features the integrity of MOF powders, proving their excellent processability. Moreover, Eu0.002Tb0.018-BDPO@PVA shows excellent temperature sensing performance with a high sensitivity of 3.7% K^(−1) in the temperature range of 303 K–423 K. CUST-623 and CUST-624 can be used as multiresponse fluorescent sensors for detecting Fe^(3+), Cr_(2)O_(7)^(2−), CrO_(4)^(2−) and TNP. In addition, the mechanism of fluorescence sensing is investigated by infrared (IR) spectroscopy, powder X-ray diffraction (PXRD) and ultraviolet–visible (UV-vis) spectroscopy. This work provides a general method for constructing Ln-MOF sensor materials with multifunctional luminescence characteristics.
基金supported by the National Natural Science Foundation of China(Grant No.22101020,12104038,and 21825102)the Fundamental Research Funds for the Central Universities,China(06500201 and No.FRF-TP-20-041A2)+1 种基金the ELETTRA Synchrotron Trieste for provision of synchrotron radiation(Experiment No.20210156)the staff of the XAFS Beamline for technical assistance.
文摘Negative thermal expansion(NTE)has both scientific and application value as a novel physical behavior,but the types of NTE materials are still limited.In the present work,a framework structure material,metal dicyanamide Zn[N(CN)_(2)]_(2),has been found to show biaxial negative thermal expansion in a wide temperature range(α_(a)=−11.82×10^(−6)K^(−1),α_(b)=−11.75×10^(−6)K^(−1)from 173 K–473 K).Through a joint study of variable temperature X-ray diffraction,extended X-ray absorption fine structure,Raman spectroscopy,and the maximum entropy method,the NTE mechanisms in Zn[N(CN)_(2)]_(2)have been revealed.The pronounced transverse vibration of C atoms in the multiatomic bridge linkage–N≡C–N–and the rotation of ZnN_(4)tetrahedra play a key role in biaxial negative thermal expansion.This work provides a new class of potential framework structure NTE materials.
基金the financial support received from the Department of Science and Technology,New Delhi,India(J.C.Bose National Fellowship to PKB)and the SRF from the CSIR to TKP and DD.SN thanks IIT Kanpur for a post-doctoral fellowship.
文摘The ligand 2,6,2’,6’-tetranitro-biphenyl-4,4’-dicarboxylic acid(H2L)reacts solvothermally with[Gd(NO_(3))_(3)]·6H_(2)O to produce a flexible and porous metal–organic framework,{[Gd_(2)(L)_(3)(DMF)_(4)]·(4DMF)·(3H_(2)O)}_(n)(1)(DMF=N,N’-dimethylformamide).An X-ray crystallographic study reveals that compound 1 contains a 3D framework structure with two different 1D channels(A and B)that are occupied by solvent DMF and water molecules.
基金supported by the National Natural Science Foundation of China(Nos 21875248,22201039,21905120 and 22031009).
文摘Three new potassium rare earth carbonates,namely KRE(CO_(3))_(2)(RE=Eu,Gd,Tb),were synthesized successfully.Their structures feature a novel[RE(CO_(3))_(2)]-3D framework with 1D channels along the c axis filled with K+cations.Among them,KEu(CO_(3))_(2) and KTb(CO_(3))_(2) emit strong red and green photoluminescence,respectively.The birefringence values of KRE(CO_(3))_(2) were measured as 0.149,0.162 and 0.215 at 546 nm,respectively.Remarkably,KTb(CO_(3))_(2) has the largest experimental birefringence among carbonates reported.
基金Experimental Center of Advanced Materials in Beijing Institute of TechnologyNational Key R&D Program of China,Grant/Award Number:2019YFA0705602+2 种基金National Natural Science Foundation of China,Grant/Award Numbers:51772029,51972029Shandong Huana New Energy Technology Co.,Ltd.Teli Young Scholars of Beijing Institute of Technology。
文摘The demand to increase energy density of rechargeable batteries for portable electronic devices and electric vehicles and to reduce the cost for grid-scale energy storage necessitates the exploration of new chemistries of electrode materials for rechargeable batteries.The open framework-structure of Prussian-blue materials has recently been demonstrated as a promising cathode host for a variety of monovalent and multivalent cations with the tunable working voltage and discharge capacities.Recent progress toward the application of Prussian-blue cathode materials for rechargeable batteries is reviewed,with special emphasis on charge-storage mechanisms of different insertion species,factors influencing electrochemical performances,and possible approaches to overcome their intrinsic limitations.
