An aminophenol ligand, N,N,N＇-tri（2-hydroxy-5-methylbenzyl）-l,2-ethanediamine, was prepared through the Marmich reaction, and structurally characterized by NMR, IR, MS and single-crystal X-ray diffraction. The titl...An aminophenol ligand, N,N,N＇-tri（2-hydroxy-5-methylbenzyl）-l,2-ethanediamine, was prepared through the Marmich reaction, and structurally characterized by NMR, IR, MS and single-crystal X-ray diffraction. The title compound （C26H32N2O3, Mr = 420.54） belongs to the monoclinic system, space group P21/n with a = 8.6233（14）, b = 10.2655（16）, c = 26.017（4） A, β = 95.797（2）°, V = 2291.3（6） A^3, Z = 4, the final R = 0.0461 and wR = 0.1139 for 4267 unique reflections （Rint = 0.028） with 11691 observed ones （I〉 2a（I））.展开更多
The crystal of the title compound C, C 30 H 30 N 2O 3S has been prepared by reaction of 1,5 benzothiazepine with N protected glycine and determined by X ray single crystal diffraction. Crystal data:...The crystal of the title compound C, C 30 H 30 N 2O 3S has been prepared by reaction of 1,5 benzothiazepine with N protected glycine and determined by X ray single crystal diffraction. Crystal data: M r =498.62, triclinic with P 1 space group, a=10.880(2), b=13.955(3), c=9.537(2), α=99.34(3)°, β=110.43(3)°, γ=88 56(3)°, V=1338.2(5) 3, F(000)=528, λ (Mo Kα)=0.71073, Z=2, D c =1 237g/cm 3, μ =0.154mm -1 . Final R=0.0453, wR =0.1256 for 3491 observed reflections 〔 I>2σ(I) 〕. Structure analysis reveals that the substituents at C(23) and C(7) in four membered ring are located on the same side. The conformation of seven membered ring is chair like.展开更多
Two new coordination polymers [Cd（EBLA）（ip）（H2O）] （1） and [Ni（EBSA） （im）2（H2O）], （2） were synthesized by hydrothermal and solution methods using 2,2＇-dithio- salicylicacid （EBSA）, lH-imidazo[4,5-f][...Two new coordination polymers [Cd（EBLA）（ip）（H2O）] （1） and [Ni（EBSA） （im）2（H2O）], （2） were synthesized by hydrothermal and solution methods using 2,2＇-dithio- salicylicacid （EBSA）, lH-imidazo[4,5-f][1,10]phenanthroline （ip）, imidazole （im）, Cd（NO3）2-4H2O and Ni（NOa）z＇6H20. The complexes were characterized by elemental analysis and FT-IR. Meanwhile, the crystal structures, fluorescence properties of complex 1 and thermogravimetrie analysis of complex 2 have been studied. In complex 1, 2,2＇-dicarboxydiphenylthioether （EBLA） was prepared with 2,2＇-dithiosalicylicacid （EBSA） in situ reaction by hydrothermal method. Complex 1 is a dinuclear structure and Cd2＋ is five-coordinated in a distorted trigonal bipyramidal geometry. Complex 2 is a one-dimensional infinite linear chain and Ni2＋ is six-coordinated to form a distorted octahedral geometry. Hydrogen bonding and π-π interactions are observed in these complexes.展开更多
Two new quaternary rare-earth chalcogenides,Al_（0.42）Sm_3（Si_（0.74）Al_（0.26））S_7（1） and Al_（0.38）Gd_3（Si_（0.86）Al_（0.14））S_7（2）,have been synthesized by a facile solid-state route with boron as the...Two new quaternary rare-earth chalcogenides,Al_（0.42）Sm_3（Si_（0.74）Al_（0.26））S_7（1） and Al_（0.38）Gd_3（Si_（0.86）Al_（0.14））S_7（2）,have been synthesized by a facile solid-state route with boron as the reducing reagent.They crystallize in the noncentrosymmetric hexagonal space group P6_3,belonging to the Ce_6Al_（3.33）S_（14） structure-type.Their 3-D structures feature 3-D frameworks constructed by RES_8 bicapped trigonal prisms,and Al and Si occupy the octahedral and tetrahedral voids,respectively.Al（2） and Si（1） co-occupying the 2b site and Al（1） partially occupying the 2a site have to be considered for the stability of the structures and charge balances.The Ce_6Al_（3.33）S_（14） structure-type compounds with their rich compositions and traits are discussed.The diffuse reflectance spectrum measurement of 2 indicates that it has an energy gap of 2.13 eV.展开更多
Density functional theory （DFT） calculations, at the B3LYP/6-311G＊＊ level of theory, were performed to study the reaction mechanism and potenti4the potential energy surface of the studied reactions was investigate...Density functional theory （DFT） calculations, at the B3LYP/6-311G＊＊ level of theory, were performed to study the reaction mechanism and potenti4the potential energy surface of the studied reactions was investigated. Our calculation results show that [2 ＋ 2] and [4 ＋ 4] reactions are concerted and synchronous processes; while [4 ＋ 2] reactions proceed via a concerted but asynchronous way in general. [2 ＋ 2] and [4 ＋ 2] reactions of germabenzenes and 1-germana- phthalene proceed much more easily than the corresponding [4 ＋ 4] reaction, both thermo- dynamically and kinetically; while most [4 ＋ 2] paths have lower activation barrier than the corres- ponding [2 ＋ 2] ones. As the number of six-membered aromatic rings in reactant molecules becomes larger, [2 ＋ 2], [4 ＋ 2] and [4 ＋ 4] reactions become easier to proceed. The influence of substituents at the Ge atom of germabenzenes on the potential energy surface of [2 ＋ 2] and [4 ＋ 2] reactions correlates with their electronic properties and volume. Solvent effect is not crucial for the potential energy surfaces of the studied reactions.展开更多
A new zero-dimensional（0D） thioborate Ba_9B_3GaS_（15） has been discovered by conventional high-temperature solid-state reaction. The compound crystallizes in orthorhombic space group Pbca with a = 8.4759（8）,b = ...A new zero-dimensional（0D） thioborate Ba_9B_3GaS_（15） has been discovered by conventional high-temperature solid-state reaction. The compound crystallizes in orthorhombic space group Pbca with a = 8.4759（8）,b = 22.266（2）,c = 31.426（3） ？,V = 5931（2） ？~3,Z = 8,Mr = 1819.11,Dc = 4.075 g/cm3,μ = 13.684 mm^（-1）,F（000） = 6320,S = 1.034,（Δρ）max = 5.039,（Δρ）min = –5.409 e/？~3,the final R = 0.0362 and w R = 0.1053 for 19243 observed reflections with I 〉 2σ（I）. The structure is constructed by discrete [BS_3]^（3–） trigonal planes and isolated [GaS_4]^（5–） tetrahedra with Ba^（2＋） and isolated S^（2–） filled among them. The UV-Vis-near-IR spectrum reveals a wide band gap of 3.15 eV that agrees with the electronic structure calculation.展开更多
One new quaternary rare-earth sulfide, FeSm6Si2S（14）, has been synthesized by a facile solid-state route with boron as the reducing reagent. It crystallizes in the noncentrosymmetric hexagonal space group P63, belon...One new quaternary rare-earth sulfide, FeSm6Si2S（14）, has been synthesized by a facile solid-state route with boron as the reducing reagent. It crystallizes in the noncentrosymmetric hexagonal space group P63, belonging to the Ce6Al（3.33）S（14） structure-type, and the AxRE3MQ7 family. Its crystal structure features a 3-D framework constructed by SmS 8 bicapped trigonal prisms, where Fe and Si atoms occupy the octahedral（2a） and tetrahedral（2c） voids, respectively. The FeS 6 octahedra are connected with each other to form a chain along the b direction. FeSm6Si2S（14） represents a new chemical composition among the large family of AxRE3MQ7 compounds. The other related compounds containing transition metal are also discussed.展开更多
A novel ternary rare-earth sulfide, CsYb7S（11）, has been successfully synthesized by high-temperature solid-state reaction of an elemental mixture with modified Cs Cl flux. The single-crystal X-ray diffraction data ...A novel ternary rare-earth sulfide, CsYb7S（11）, has been successfully synthesized by high-temperature solid-state reaction of an elemental mixture with modified Cs Cl flux. The single-crystal X-ray diffraction data reveal its orthorhombic symmetry in space group Cmca（no. 64） with a = 15.271（3）, b = 13.414（2）, c = 18.869（3） A°, V = 3865.2（2） A°^3, Z = 8, Mr = 1696.85, Dc = 5.832 g/cm^3, μ = 36.538 mm^-1, F（000） = 5768, the final R = 0.0225 and w R = 0.0517 for 2258 observed reflections with I 〉 2σ（I）, 2.67〈θ〈27.48o, w = 1/[σ^2（Fo^2） ＋（0.0443 P）2 ＋ 8.7453 P], where P =（Fo^2 ＋ 2Fc^2）/3, S = 1.036,（Δρ）max = 1.609 and（Δρ）min = –1.922. The remarkable structural feature is the dual tricapped Cs2@S18 cube closed cavities far apart within the three-dimensional [Yb7S（11）]-covalent bonding matrix. Magnetic susceptibility measurements show that the title compound exhibits temperature-dependent（50～300 K） para-magnetism and obey the Curie-Weiss law. Moreover, the optical gap of 2.03 Ev for CsYb7S11 was deduced from the UV/Vis reflectance spectroscopy and DFT study indicates an indirect band gap with an electronic transfer excitation of S-3p to Yb-5d orbital.展开更多
Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound w...Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.展开更多
A new cobalt selenite,Ca_2Co（HSeO3）_2（SeO_3）_2,was synthesized by a conventional hydrothermal method. Single-crystal X-ray diffraction analysis reveals that Ca_2Co（HSeO3）_2（SeO_3）_2 crystallizes in triclinic s...A new cobalt selenite,Ca_2Co（HSeO3）_2（SeO_3）_2,was synthesized by a conventional hydrothermal method. Single-crystal X-ray diffraction analysis reveals that Ca_2Co（HSeO3）_2（SeO_3）_2 crystallizes in triclinic system,space group P1,with a = 5.330（5）,b = 7.047（7）,c = 8.457（9） ？,V = 285.0（5） ？~3,Z = 1,Mr = 646.93,Dc = 3.769,μ = 15.235 mm^（-1）,F（000） = 299.0,the final R = 0.0452 and wR = 0.1169 for observed 1265 reflections with I 〉 2σ（I）. The title compound consists of isolated chains built from CoO_6 octahedra and SeO_3 pyramids. In this structure,the chains are separated by Ca^（2＋） cations. Magnetic measurements confirm that the title compound exhibits long-range antiferromagnetic ordering at 3 K and field-induced magnetic transition at 2 T.展开更多
WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas mixtures.Experimental data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,t...WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas mixtures.Experimental data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,texture morphology, mechanical and optical properties of the WNxfilms. With increasing nitrogen a phase transition from a single WNxphase with low crystallinity structure to a well-mixed crystallized hexagonal WNxand face-centered-cubic W2N phases appears. Relatively smooth morphology at lower N2concentration changes to a really smooth morphology and then granular with coarse surface at higher N2concentration. The SEM observation clearly shows a columnar structure at lower N2concentration and a dense nanoplates one for higher nitrogen content. The hardness of WNxthin films mainly depends on the film microstructure. The absorbance peak position shifts to shorter wavelength continuously with increasing nitrogen amount and decreasing particle size.展开更多
A new intermetallic compound, SmCuT.vslns.27, has been synthesized by solid-state reaction of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction stu...A new intermetallic compound, SmCuT.vslns.27, has been synthesized by solid-state reaction of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction study. SmCu7.731n3.27 crystallizes in tetragonal space group P4/mbm with a = 8.6213（4）, c = 10.2538（9）, V= 762.13（8） A3, Z = 4, M,. = 1018.90, Dc= 8.880 g/cm3,μ = 38.244 mm-1, F（000） = 1789, and the final R = 0.0374 and wR = 0.0836 for 514 observed reflections with I 〉 2σ（I）. The structure of SmCu7.69In3.31 belongs to a new structure type and features a three-dimensional （3D） [Cusln2M4] （M = Cu/In） framework composed of [CusinnM4] clusters interconnected via sharing In atoms as well as Cu-ln and In-In bonds. The Sm atoms are located in the one-dimensional （1 D） tunnels along the c-axis. The structural relationship of the title compound with other similar Sm-Cu-In phases was also studied. Band structure calculations based on Density Functional Theory （DFT） method indicate that SmCuT.69In3.31 is metallic.展开更多
Solvothermal reaction of manganese（II） salt with monosodium 2-sulfoterephthalate（2-NaH2stp） and two multi-pyridine N-containing auxiliary ligands results in the formation of two new complexes formulated with [Mn2...Solvothermal reaction of manganese（II） salt with monosodium 2-sulfoterephthalate（2-NaH2stp） and two multi-pyridine N-containing auxiliary ligands results in the formation of two new complexes formulated with [Mn2（Hstp）2（bpp）2（H2O）4]（1） and [Mn3（stp）2（tpy）3（H2O）]（H2O）5（2）（bpp = benz-2,3-pyrimidine-[2,3-f]-1,10-phenanthroline, tpy = 2,2＇：6＇,2＇＇-terpyridine）. X-ray diffraction structural analyses of two complexes reveal their structural diversity（0D and 1D） due to the difference of auxiliary ligands. 1 is a discrete structure, in which the Mn（Ⅱ） ion is hexa-coordinated with one stp, one bpp ligand and two water molecules. Complex 2 is a one-dimensional（1D） chain-like structure with three crystallographically independent Mn（Ⅱ） ions. The photoluminescent properties could be assigned to the π-π＊ transition of 2-sulfoterephthalate ligands.展开更多
The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-orga...The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-organic framework containing octanuclear Zn（II） units, [Zn4（MeO-ip）3（OH）2（bmip）]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348（3）, b = 14.163（4）, c = 15.088（4） , α = 108.537（2）, β = 106.542（2）, γ = 103.106（1）o, V = 2065.4（9） -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-（-3）, μ = 2.375 mm-（-1）, S = 1.015, F（000） = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections（I 〉 2σ（I））. The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.展开更多
We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials,which were formed by layered deposition of multiple anatase TiO2 nanosheets.The Au nanoparticles were stabilized by structural defec...We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials,which were formed by layered deposition of multiple anatase TiO2 nanosheets.The Au nanoparticles were stabilized by structural defects in each TiO2 nanosheet,including crystal steps and edges,thereby fixing the Au-TiO2 perimeter interface.Reactant transfer occurred along the gaps between these TiO2 nanosheet layers and in contact with catalytically active sites at the Au-TiO2 interface.The doped Au induced the formation of oxygen vacancies in the Au-TiO2 interface.Such vacancies are essential for generating active oxygen species（-＊O^-） on the TiO2 surface and Ti^3＋ ions in bulk TiO2.These ions can then form Ti^3＋-O^--Ti^4＋species,which are known to enhance the catalytic activity of formaldehyde（HCHO） oxidation.These studies on structural and oxygen vacancy defects in Au/TiO2 samples provide a theoretical foundation for the catalytic mechanism of HCHO oxidation on oxide-supported Au materials.展开更多
High entropy alloys(HEAs)have garnered significant attention due to their distinctive properties,while their precise regulation remains at infancy stage.Herein,we report PtSnBiPdIn HEA nanoparticles with tensilestrain...High entropy alloys(HEAs)have garnered significant attention due to their distinctive properties,while their precise regulation remains at infancy stage.Herein,we report PtSnBiPdIn HEA nanoparticles with tensilestrain and nanoporous structures as high-performance electrocatalysts for oxidation of ethylene glycol to CO_(2).The mass activity(MA)of the PtSnBiPdIn/C catalyst for alkaline ethylene glycol oxidation reaction(EGOR)are 29.76 A·mgPt+Pd−1,which not only substantially surpasses those of commercial Pt/C and Pd/C catalysts but also ranks among the best reported EGOR catalysts.Moreover,this catalyst also greatly enhances in electrocatalytic performance for both methanol oxidation reaction(MOR)and ethanol oxidation reaction(EOR),showcasing its versatility across a wide range of alcohol oxidation reactions.In-situ Fourier transform infrared(FTIR)spectroscopy confirms the preferential selection of the non-CO reaction pathway.Density functional theory(DFT)calculation reveals that the PtSnBiPdIn HEA nanoparticles exhibit enhanced electron transfer,superior catalytic activity,and remarkable CO poisoning resistance.展开更多
Highly efficient and durable water oxidation electrocatalysts are critically important in a wide range of clean energy technologies,including water electrolyzers and rechargeable metal-air batteries.Here,we report a n...Highly efficient and durable water oxidation electrocatalysts are critically important in a wide range of clean energy technologies,including water electrolyzers and rechargeable metal-air batteries.Here,we report a novel sonochemical approach to synthesize amorphous nickel-iron oxides/carbon nanohybrids with tunable compositions for the oxygen evolution reaction （OER）.The sonochemically synthesized amorphous electrocatalysts with optimal composition exhibit a low overpotential of 290 mV at 10 mA＆#183;cm-2 and a Tafel slope of 31 mV＆#183;decade-1 in a 0.1 M KOH electrolyte,outperforming the benchmark RuO2 catalyst.Meanwhile,these nanohybrids are also highly stable and remain amorphous even after prolonged cycling.In addition to amorphism,sonochemistry endows as-prepared nickel-iron oxides/carbon nanohybrids with a simultaneously formed carbon scaffold and internal Ni（0）,which can enhance the stability and activity for the OER.This work demonstrates that sonochemistry is a unique method for synthesizing amorphous metal oxides toward an efficient and durable OER.展开更多
A variety of phenyl alkyl sulfides were oxidized enantioselectively with NaIO_4 in chiral micellar systems formed from eight chiral surfactants,to give optical active sulfoxides.The enantiomer excesses ranged from 1.6...A variety of phenyl alkyl sulfides were oxidized enantioselectively with NaIO_4 in chiral micellar systems formed from eight chiral surfactants,to give optical active sulfoxides.The enantiomer excesses ranged from 1.6 to 15.0%.To understand the mechanistic detail of this asymmetric oxi- dation in chiral micelle,the effects of structure both in substrates and surfactants on the optical yield of the oxidation were studied and discussed.Generally,increasing the alkyl chain length both in sur- factants and in substrates enhances the optical yield,also the surfactant with hydroxy group at its appropriate position gives better enantioselectivity,suggesting the enzymic characteristics of the chiral micelle.展开更多
基金supported by Shandong Province Higher Educational Science and Technology Program (J09LB03)
文摘An aminophenol ligand, N,N,N＇-tri（2-hydroxy-5-methylbenzyl）-l,2-ethanediamine, was prepared through the Marmich reaction, and structurally characterized by NMR, IR, MS and single-crystal X-ray diffraction. The title compound （C26H32N2O3, Mr = 420.54） belongs to the monoclinic system, space group P21/n with a = 8.6233（14）, b = 10.2655（16）, c = 26.017（4） A, β = 95.797（2）°, V = 2291.3（6） A^3, Z = 4, the final R = 0.0461 and wR = 0.1139 for 4267 unique reflections （Rint = 0.028） with 11691 observed ones （I〉 2a（I））.
文摘The crystal of the title compound C, C 30 H 30 N 2O 3S has been prepared by reaction of 1,5 benzothiazepine with N protected glycine and determined by X ray single crystal diffraction. Crystal data: M r =498.62, triclinic with P 1 space group, a=10.880(2), b=13.955(3), c=9.537(2), α=99.34(3)°, β=110.43(3)°, γ=88 56(3)°, V=1338.2(5) 3, F(000)=528, λ (Mo Kα)=0.71073, Z=2, D c =1 237g/cm 3, μ =0.154mm -1 . Final R=0.0453, wR =0.1256 for 3491 observed reflections 〔 I>2σ(I) 〕. Structure analysis reveals that the substituents at C(23) and C(7) in four membered ring are located on the same side. The conformation of seven membered ring is chair like.
基金the Foundation of Guangdong Province(No.S2012020011054 and 2011B090400415)Zhanjiang Municipality(No.2011C3108001)
文摘Two new coordination polymers [Cd（EBLA）（ip）（H2O）] （1） and [Ni（EBSA） （im）2（H2O）], （2） were synthesized by hydrothermal and solution methods using 2,2＇-dithio- salicylicacid （EBSA）, lH-imidazo[4,5-f][1,10]phenanthroline （ip）, imidazole （im）, Cd（NO3）2-4H2O and Ni（NOa）z＇6H20. The complexes were characterized by elemental analysis and FT-IR. Meanwhile, the crystal structures, fluorescence properties of complex 1 and thermogravimetrie analysis of complex 2 have been studied. In complex 1, 2,2＇-dicarboxydiphenylthioether （EBLA） was prepared with 2,2＇-dithiosalicylicacid （EBSA） in situ reaction by hydrothermal method. Complex 1 is a dinuclear structure and Cd2＋ is five-coordinated in a distorted trigonal bipyramidal geometry. Complex 2 is a one-dimensional infinite linear chain and Ni2＋ is six-coordinated to form a distorted octahedral geometry. Hydrogen bonding and π-π interactions are observed in these complexes.
基金supported by the Higher Education Science Foundation of Jiangsu Province(No.15KJB150031)State Key Laboratory of Structural Chemistry(No.20150009)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe technical support received from the Testing Center of Yangzhou University
文摘Two new quaternary rare-earth chalcogenides,Al_（0.42）Sm_3（Si_（0.74）Al_（0.26））S_7（1） and Al_（0.38）Gd_3（Si_（0.86）Al_（0.14））S_7（2）,have been synthesized by a facile solid-state route with boron as the reducing reagent.They crystallize in the noncentrosymmetric hexagonal space group P6_3,belonging to the Ce_6Al_（3.33）S_（14） structure-type.Their 3-D structures feature 3-D frameworks constructed by RES_8 bicapped trigonal prisms,and Al and Si occupy the octahedral and tetrahedral voids,respectively.Al（2） and Si（1） co-occupying the 2b site and Al（1） partially occupying the 2a site have to be considered for the stability of the structures and charge balances.The Ce_6Al_（3.33）S_（14） structure-type compounds with their rich compositions and traits are discussed.The diffuse reflectance spectrum measurement of 2 indicates that it has an energy gap of 2.13 eV.
基金Henan Provincial Fundamental and Frontier Technological Research Program (No. 092300410207)
文摘Density functional theory （DFT） calculations, at the B3LYP/6-311G＊＊ level of theory, were performed to study the reaction mechanism and potenti4the potential energy surface of the studied reactions was investigated. Our calculation results show that [2 ＋ 2] and [4 ＋ 4] reactions are concerted and synchronous processes; while [4 ＋ 2] reactions proceed via a concerted but asynchronous way in general. [2 ＋ 2] and [4 ＋ 2] reactions of germabenzenes and 1-germana- phthalene proceed much more easily than the corresponding [4 ＋ 4] reaction, both thermo- dynamically and kinetically; while most [4 ＋ 2] paths have lower activation barrier than the corres- ponding [2 ＋ 2] ones. As the number of six-membered aromatic rings in reactant molecules becomes larger, [2 ＋ 2], [4 ＋ 2] and [4 ＋ 4] reactions become easier to proceed. The influence of substituents at the Ge atom of germabenzenes on the potential energy surface of [2 ＋ 2] and [4 ＋ 2] reactions correlates with their electronic properties and volume. Solvent effect is not crucial for the potential energy surfaces of the studied reactions.
基金Supported by the National Natural Science Foundation of China(21233009,21225104,91422303,21301175 and 21171168)
文摘A new zero-dimensional（0D） thioborate Ba_9B_3GaS_（15） has been discovered by conventional high-temperature solid-state reaction. The compound crystallizes in orthorhombic space group Pbca with a = 8.4759（8）,b = 22.266（2）,c = 31.426（3） ？,V = 5931（2） ？~3,Z = 8,Mr = 1819.11,Dc = 4.075 g/cm3,μ = 13.684 mm^（-1）,F（000） = 6320,S = 1.034,（Δρ）max = 5.039,（Δρ）min = –5.409 e/？~3,the final R = 0.0362 and w R = 0.1053 for 19243 observed reflections with I 〉 2σ（I）. The structure is constructed by discrete [BS_3]^（3–） trigonal planes and isolated [GaS_4]^（5–） tetrahedra with Ba^（2＋） and isolated S^（2–） filled among them. The UV-Vis-near-IR spectrum reveals a wide band gap of 3.15 eV that agrees with the electronic structure calculation.
基金supported by the Higher Education Science Foundation of Jiangsu Province(No.15KJB150031)State Key Laboratory of Structural Chemistry(No.20150009)Yangzhou Engineering Technology Research Center of Petrochemical New Materials(YZM2015086)
文摘One new quaternary rare-earth sulfide, FeSm6Si2S（14）, has been synthesized by a facile solid-state route with boron as the reducing reagent. It crystallizes in the noncentrosymmetric hexagonal space group P63, belonging to the Ce6Al（3.33）S（14） structure-type, and the AxRE3MQ7 family. Its crystal structure features a 3-D framework constructed by SmS 8 bicapped trigonal prisms, where Fe and Si atoms occupy the octahedral（2a） and tetrahedral（2c） voids, respectively. The FeS 6 octahedra are connected with each other to form a chain along the b direction. FeSm6Si2S（14） represents a new chemical composition among the large family of AxRE3MQ7 compounds. The other related compounds containing transition metal are also discussed.
基金supported by the National Natural Science Foundation of China(21301175,21233009,21571020 and 91422303)the Natural Science Foundation of Fujian Province(2015J01071)
文摘A novel ternary rare-earth sulfide, CsYb7S（11）, has been successfully synthesized by high-temperature solid-state reaction of an elemental mixture with modified Cs Cl flux. The single-crystal X-ray diffraction data reveal its orthorhombic symmetry in space group Cmca（no. 64） with a = 15.271（3）, b = 13.414（2）, c = 18.869（3） A°, V = 3865.2（2） A°^3, Z = 8, Mr = 1696.85, Dc = 5.832 g/cm^3, μ = 36.538 mm^-1, F（000） = 5768, the final R = 0.0225 and w R = 0.0517 for 2258 observed reflections with I 〉 2σ（I）, 2.67〈θ〈27.48o, w = 1/[σ^2（Fo^2） ＋（0.0443 P）2 ＋ 8.7453 P], where P =（Fo^2 ＋ 2Fc^2）/3, S = 1.036,（Δρ）max = 1.609 and（Δρ）min = –1.922. The remarkable structural feature is the dual tricapped Cs2@S18 cube closed cavities far apart within the three-dimensional [Yb7S（11）]-covalent bonding matrix. Magnetic susceptibility measurements show that the title compound exhibits temperature-dependent（50～300 K） para-magnetism and obey the Curie-Weiss law. Moreover, the optical gap of 2.03 Ev for CsYb7S11 was deduced from the UV/Vis reflectance spectroscopy and DFT study indicates an indirect band gap with an electronic transfer excitation of S-3p to Yb-5d orbital.
文摘Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.
基金financially supported by the National Basic Research Program of China(No.2012CB921701)the National Natural Science Foundation of China(No.2157323521403234)
文摘A new cobalt selenite,Ca_2Co（HSeO3）_2（SeO_3）_2,was synthesized by a conventional hydrothermal method. Single-crystal X-ray diffraction analysis reveals that Ca_2Co（HSeO3）_2（SeO_3）_2 crystallizes in triclinic system,space group P1,with a = 5.330（5）,b = 7.047（7）,c = 8.457（9） ？,V = 285.0（5） ？~3,Z = 1,Mr = 646.93,Dc = 3.769,μ = 15.235 mm^（-1）,F（000） = 299.0,the final R = 0.0452 and wR = 0.1169 for observed 1265 reflections with I 〉 2σ（I）. The title compound consists of isolated chains built from CoO_6 octahedra and SeO_3 pyramids. In this structure,the chains are separated by Ca^（2＋） cations. Magnetic measurements confirm that the title compound exhibits long-range antiferromagnetic ordering at 3 K and field-induced magnetic transition at 2 T.
文摘WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas mixtures.Experimental data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,texture morphology, mechanical and optical properties of the WNxfilms. With increasing nitrogen a phase transition from a single WNxphase with low crystallinity structure to a well-mixed crystallized hexagonal WNxand face-centered-cubic W2N phases appears. Relatively smooth morphology at lower N2concentration changes to a really smooth morphology and then granular with coarse surface at higher N2concentration. The SEM observation clearly shows a columnar structure at lower N2concentration and a dense nanoplates one for higher nitrogen content. The hardness of WNxthin films mainly depends on the film microstructure. The absorbance peak position shifts to shorter wavelength continuously with increasing nitrogen amount and decreasing particle size.
基金supported by the National Natural Science Foundation of China(No.21101075 and 21201081)the research foundation for excellent young and middle-aged scientists of Shandong Province(No.BS2011CL009BS2012CL008 and ZR2013BL004)
文摘A new intermetallic compound, SmCuT.vslns.27, has been synthesized by solid-state reaction of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction study. SmCu7.731n3.27 crystallizes in tetragonal space group P4/mbm with a = 8.6213（4）, c = 10.2538（9）, V= 762.13（8） A3, Z = 4, M,. = 1018.90, Dc= 8.880 g/cm3,μ = 38.244 mm-1, F（000） = 1789, and the final R = 0.0374 and wR = 0.0836 for 514 observed reflections with I 〉 2σ（I）. The structure of SmCu7.69In3.31 belongs to a new structure type and features a three-dimensional （3D） [Cusln2M4] （M = Cu/In） framework composed of [CusinnM4] clusters interconnected via sharing In atoms as well as Cu-ln and In-In bonds. The Sm atoms are located in the one-dimensional （1 D） tunnels along the c-axis. The structural relationship of the title compound with other similar Sm-Cu-In phases was also studied. Band structure calculations based on Density Functional Theory （DFT） method indicate that SmCuT.69In3.31 is metallic.
基金supported by the Postdoctoral Science Foundation of China(No.2014M562403)National Natural Science Foundation of China(No.21573189)
文摘Solvothermal reaction of manganese（II） salt with monosodium 2-sulfoterephthalate（2-NaH2stp） and two multi-pyridine N-containing auxiliary ligands results in the formation of two new complexes formulated with [Mn2（Hstp）2（bpp）2（H2O）4]（1） and [Mn3（stp）2（tpy）3（H2O）]（H2O）5（2）（bpp = benz-2,3-pyrimidine-[2,3-f]-1,10-phenanthroline, tpy = 2,2＇：6＇,2＇＇-terpyridine）. X-ray diffraction structural analyses of two complexes reveal their structural diversity（0D and 1D） due to the difference of auxiliary ligands. 1 is a discrete structure, in which the Mn（Ⅱ） ion is hexa-coordinated with one stp, one bpp ligand and two water molecules. Complex 2 is a one-dimensional（1D） chain-like structure with three crystallographically independent Mn（Ⅱ） ions. The photoluminescent properties could be assigned to the π-π＊ transition of 2-sulfoterephthalate ligands.
基金supported by the Natural Science Foundation of Fujian Province(2015J01038)Provincial Education Department of Fujian(JA12070)State Key Laboratory of Structural Chemistry(20150015)
文摘The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-organic framework containing octanuclear Zn（II） units, [Zn4（MeO-ip）3（OH）2（bmip）]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348（3）, b = 14.163（4）, c = 15.088（4） , α = 108.537（2）, β = 106.542（2）, γ = 103.106（1）o, V = 2065.4（9） -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-（-3）, μ = 2.375 mm-（-1）, S = 1.015, F（000） = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections（I 〉 2σ（I））. The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.
基金supported by the National Natural Science Foundation of China (21107124, 21337003)the Youth Innovation Promotion Association (2011037)Science Promotion Program of Research Center for Eco-Environmental Sciences, Chinese Academic Sciences (No. 121311RCEES-QN-20130046F)
文摘We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials,which were formed by layered deposition of multiple anatase TiO2 nanosheets.The Au nanoparticles were stabilized by structural defects in each TiO2 nanosheet,including crystal steps and edges,thereby fixing the Au-TiO2 perimeter interface.Reactant transfer occurred along the gaps between these TiO2 nanosheet layers and in contact with catalytically active sites at the Au-TiO2 interface.The doped Au induced the formation of oxygen vacancies in the Au-TiO2 interface.Such vacancies are essential for generating active oxygen species（-＊O^-） on the TiO2 surface and Ti^3＋ ions in bulk TiO2.These ions can then form Ti^3＋-O^--Ti^4＋species,which are known to enhance the catalytic activity of formaldehyde（HCHO） oxidation.These studies on structural and oxygen vacancy defects in Au/TiO2 samples provide a theoretical foundation for the catalytic mechanism of HCHO oxidation on oxide-supported Au materials.
基金funding from the National Natural Science Foundation of China(Nos.12475323 and U21A20317)the Natural Science Research Project of Universities in Anhui Province(Nos.2022AH050112 and 2024AH050082)+3 种基金the Project of Anhui Provincial Department of Education(No.2022AH010004)the Fund of Key Laboratory of Advanced Materials of Ministry of Education No(Advmat-2401)the Natural Science Foundation of Anhui Province(No.2108085MB55)the Fund of Development of High-Resolution X-ray Fluorescence Analyzer.
文摘High entropy alloys(HEAs)have garnered significant attention due to their distinctive properties,while their precise regulation remains at infancy stage.Herein,we report PtSnBiPdIn HEA nanoparticles with tensilestrain and nanoporous structures as high-performance electrocatalysts for oxidation of ethylene glycol to CO_(2).The mass activity(MA)of the PtSnBiPdIn/C catalyst for alkaline ethylene glycol oxidation reaction(EGOR)are 29.76 A·mgPt+Pd−1,which not only substantially surpasses those of commercial Pt/C and Pd/C catalysts but also ranks among the best reported EGOR catalysts.Moreover,this catalyst also greatly enhances in electrocatalytic performance for both methanol oxidation reaction(MOR)and ethanol oxidation reaction(EOR),showcasing its versatility across a wide range of alcohol oxidation reactions.In-situ Fourier transform infrared(FTIR)spectroscopy confirms the preferential selection of the non-CO reaction pathway.Density functional theory(DFT)calculation reveals that the PtSnBiPdIn HEA nanoparticles exhibit enhanced electron transfer,superior catalytic activity,and remarkable CO poisoning resistance.
基金We thank the Photoemission Endstation （BL10B） in National Synchrotron Radiation Laboratory （NSRL） for collecting X-ray data. This work was supported by the National Key Basic Research Program of China （Nos. 2015CB351903 and 2014CB848900）, the National Natural Science Foundation of China （Nos. 21474095, 11574280, 11605201, and U1532112）, CAS Key Research Program of Frontier Sciences （No. QYZDB-SSW-SLH018）, and the Fundamental Research Funds for the Central Universities.
文摘Highly efficient and durable water oxidation electrocatalysts are critically important in a wide range of clean energy technologies,including water electrolyzers and rechargeable metal-air batteries.Here,we report a novel sonochemical approach to synthesize amorphous nickel-iron oxides/carbon nanohybrids with tunable compositions for the oxygen evolution reaction （OER）.The sonochemically synthesized amorphous electrocatalysts with optimal composition exhibit a low overpotential of 290 mV at 10 mA＆#183;cm-2 and a Tafel slope of 31 mV＆#183;decade-1 in a 0.1 M KOH electrolyte,outperforming the benchmark RuO2 catalyst.Meanwhile,these nanohybrids are also highly stable and remain amorphous even after prolonged cycling.In addition to amorphism,sonochemistry endows as-prepared nickel-iron oxides/carbon nanohybrids with a simultaneously formed carbon scaffold and internal Ni（0）,which can enhance the stability and activity for the OER.This work demonstrates that sonochemistry is a unique method for synthesizing amorphous metal oxides toward an efficient and durable OER.
文摘A variety of phenyl alkyl sulfides were oxidized enantioselectively with NaIO_4 in chiral micellar systems formed from eight chiral surfactants,to give optical active sulfoxides.The enantiomer excesses ranged from 1.6 to 15.0%.To understand the mechanistic detail of this asymmetric oxi- dation in chiral micelle,the effects of structure both in substrates and surfactants on the optical yield of the oxidation were studied and discussed.Generally,increasing the alkyl chain length both in sur- factants and in substrates enhances the optical yield,also the surfactant with hydroxy group at its appropriate position gives better enantioselectivity,suggesting the enzymic characteristics of the chiral micelle.
