A supramolecular complex of Cd（II） with 1D water tapes as pillars[Cd2（dpa）2（phen）2（H2O）2]·6H2O 1 （H2dpa = diphenic acid, phen = phenanthroline）, has been synthesized and characterized by elemental analy...A supramolecular complex of Cd（II） with 1D water tapes as pillars[Cd2（dpa）2（phen）2（H2O）2]·6H2O 1 （H2dpa = diphenic acid, phen = phenanthroline）, has been synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction analysis. The crystal is of triclinic, space group P1^- with a = 9.7029（4）, b = 11.9601（5）, c = 12.1788（4） A, α = 71.6990（10）, β = 71.8740（10）, γ = 74.4680（10）°, V = 1252.39（8） A^3, C52H48Cd2N4O16, Mr = 1209.76, Z= 1, Dc = 1.604 g/cm^3,μ = 0.925 mm^-1, F（000） = 612, R = 0.0679 and wR = 0.2514 for 3870 observed reflections （I 〉 2σ（I））. Two intramolecular Cd（II） centers of this complex are encircled by two dpa^2- ligands forming an 18-membered ring, which is further assembled into a pillared three-dimensional （3D） supramolecular architecture through the synergetic effect of intermolecular face-to-face π…π stacking and weak O-H…O hydrogen-bonding interactions. Moreover, this complex exhibits photoluminescence with the main emission bands located at about 456 nm upon excitation at 355 nm in the solid state at room temperature.展开更多
By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI o...By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line of GSGG:Cr<SUP>3+</SUP> at 70 K have been calculated, respectively. Their physical origins have been revealed. It is found that the admixture of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 70 K is remarkable under the normal pressure, and the degree of the admixture rapidly decreases with increasing pressure. The change of the degree of the admixture with the pressure plays a key role for not only the pure electronic PS of R<SUB>1</SUB> line but also the PS of R<SUB>1</SUB> line due to EPI. The detailed calculations and analyses show that the pressure-dependent behaviors of the pure electronic PS of R<SUB>1</SUB> line and the PS of R<SUB>1</SUB> line due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line, which has satisfactorily explained the experimental data (including a reversal of PS of R<SUB>1</SUB> line). In contributions to PS of R<SUB>1</SUB> line due to EPI at 70 K, the temperature-independent contribution is much larger than the temperature-dependent contribution. The former results from the interaction between the zero-point vibration of the lattice and localized electronic state.展开更多
By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI o...By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line, R<SUB>2</SUB> line, and U band of GSGG:Cr<SUP>3+</SUP> at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-degree of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line but also the PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) and the PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line). In the range of about 15 kbar ~ 45 kbar, the mergence and/or order-reversal between levels and levels take place, which cause the fluctuation of the rate of PS for with pressure. At 300 K, both the temperature-dependent contribution to R<SUB>1</SUB> line (or R<SUB>2</SUB> line or U band) from EPI and the temperature-independent one are important.展开更多
In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3＋ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D as...In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3＋ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D asynchronous spectrum confirms the occurrence of intermolecular interaction between Nd^3＋and pyridinium.However,no coordination occurs between Nd^3＋ and pyridinium.Interaction between πelectron from aromatic system and/electron from lanthanide ions account for the appearance of cross peaks in 2D asynchronous spectra.Because of the interaction,the emission spectrum of pyridinium exhibits a significant change when neodymium perchlorate was introduced into the system.展开更多
Reducing kinetic energy barriers and developing accessible active sites are critical to deliver high hydrogen evolution reaction(HER)efficiency.In this paper,we synthesized defect-modulated and heteroatom(boron)-funct...Reducing kinetic energy barriers and developing accessible active sites are critical to deliver high hydrogen evolution reaction(HER)efficiency.In this paper,we synthesized defect-modulated and heteroatom(boron)-functionalized three-dimensional(3D)bowl-shaped Ti_(3−x)C_(2)T_(y)MXene(B-TCT)nanocavities coupled with the vertical growth of MoSe_(2)nanoflakes.The B-TCT@MoSe_(2)nanohybrids catalyst delivers the overpotentials of 49.9,52.7,and 67.8 mV to reach a HER current density of 10 mA·cm^(−2)under acidic,alkaline,and neutral conditions,respectively.Such outstanding HER activity is predominantly attributed to the heteroatom functionalization,self-adapting Ti vacancy(VTi)defect modulation,and spatial configuration design in the 3D B-TCT nanocavity,which synergistically regulate the electronic structure,activate the basal plane/edge unsaturated sites,and reduce the reaction energy barrier.Experimental and theoretical calculations demonstrate that strong heterogeneous interfacial bonding interactions between B-TCT and MoSe_(2)can dramatically reduce the free energy of hydrogen adsorption and facilitate efficient interfacial charge migration,thus essentially improving the HER kinetics.We used this 3D porous nanohybrid system assembled by defectrich lamellar structures to elucidate the advantageous synergistic effects of multiple mechanisms among defect structure,heteroatom functionalization,and interfacial coupling,which provided important insights for the development of efficient hybridtype catalysts.展开更多
Subject Code:H06 With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Zou Weiguo(邹卫国)from the Institute of Biochemistry and Cell Biology,Shanghai Institutes...Subject Code:H06 With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Zou Weiguo(邹卫国)from the Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences,CAS demonstrates that E3ligase SMURF2maintains bone展开更多
基金the State Key Basic Research and Development Plan of China (001CB108906)the Knowledge Innovation Program of the Chinese Academy of Sciences, the NSF (2006J0015)the Major Special Foundation of Fujian Province (2005HZ1027, 2005HZ01-1)
文摘A supramolecular complex of Cd（II） with 1D water tapes as pillars[Cd2（dpa）2（phen）2（H2O）2]·6H2O 1 （H2dpa = diphenic acid, phen = phenanthroline）, has been synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction analysis. The crystal is of triclinic, space group P1^- with a = 9.7029（4）, b = 11.9601（5）, c = 12.1788（4） A, α = 71.6990（10）, β = 71.8740（10）, γ = 74.4680（10）°, V = 1252.39（8） A^3, C52H48Cd2N4O16, Mr = 1209.76, Z= 1, Dc = 1.604 g/cm^3,μ = 0.925 mm^-1, F（000） = 612, R = 0.0679 and wR = 0.2514 for 3870 observed reflections （I 〉 2σ（I））. Two intramolecular Cd（II） centers of this complex are encircled by two dpa^2- ligands forming an 18-membered ring, which is further assembled into a pillared three-dimensional （3D） supramolecular architecture through the synergetic effect of intermolecular face-to-face π…π stacking and weak O-H…O hydrogen-bonding interactions. Moreover, this complex exhibits photoluminescence with the main emission bands located at about 456 nm upon excitation at 355 nm in the solid state at room temperature.
文摘By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line of GSGG:Cr<SUP>3+</SUP> at 70 K have been calculated, respectively. Their physical origins have been revealed. It is found that the admixture of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 70 K is remarkable under the normal pressure, and the degree of the admixture rapidly decreases with increasing pressure. The change of the degree of the admixture with the pressure plays a key role for not only the pure electronic PS of R<SUB>1</SUB> line but also the PS of R<SUB>1</SUB> line due to EPI. The detailed calculations and analyses show that the pressure-dependent behaviors of the pure electronic PS of R<SUB>1</SUB> line and the PS of R<SUB>1</SUB> line due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line, which has satisfactorily explained the experimental data (including a reversal of PS of R<SUB>1</SUB> line). In contributions to PS of R<SUB>1</SUB> line due to EPI at 70 K, the temperature-independent contribution is much larger than the temperature-dependent contribution. The former results from the interaction between the zero-point vibration of the lattice and localized electronic state.
文摘By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line, R<SUB>2</SUB> line, and U band of GSGG:Cr<SUP>3+</SUP> at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-degree of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line but also the PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) and the PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line). In the range of about 15 kbar ~ 45 kbar, the mergence and/or order-reversal between levels and levels take place, which cause the fluctuation of the rate of PS for with pressure. At 300 K, both the temperature-dependent contribution to R<SUB>1</SUB> line (or R<SUB>2</SUB> line or U band) from EPI and the temperature-independent one are important.
基金financially supported by the National Natural Science Foundation of China(No.51373003)Beijing Natural Science Foundation(No.2122059)
文摘In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3＋ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D asynchronous spectrum confirms the occurrence of intermolecular interaction between Nd^3＋and pyridinium.However,no coordination occurs between Nd^3＋ and pyridinium.Interaction between πelectron from aromatic system and/electron from lanthanide ions account for the appearance of cross peaks in 2D asynchronous spectra.Because of the interaction,the emission spectrum of pyridinium exhibits a significant change when neodymium perchlorate was introduced into the system.
基金supported by the National Natural Science Foundation of China(Nos.52072182 and 51872145)Natural Science Foundation of Jiangsu Province(No.BK20211278)+2 种基金the China Postdoctoral Science Foundation(Nos.2019M650120 and 2020M671554)the National Synergetic Innovation Center for Advanced Materials(SICAM)Postgraduate Research Practice Innovation Program of Jiangsu Province(No.KYCX22_0977).
文摘Reducing kinetic energy barriers and developing accessible active sites are critical to deliver high hydrogen evolution reaction(HER)efficiency.In this paper,we synthesized defect-modulated and heteroatom(boron)-functionalized three-dimensional(3D)bowl-shaped Ti_(3−x)C_(2)T_(y)MXene(B-TCT)nanocavities coupled with the vertical growth of MoSe_(2)nanoflakes.The B-TCT@MoSe_(2)nanohybrids catalyst delivers the overpotentials of 49.9,52.7,and 67.8 mV to reach a HER current density of 10 mA·cm^(−2)under acidic,alkaline,and neutral conditions,respectively.Such outstanding HER activity is predominantly attributed to the heteroatom functionalization,self-adapting Ti vacancy(VTi)defect modulation,and spatial configuration design in the 3D B-TCT nanocavity,which synergistically regulate the electronic structure,activate the basal plane/edge unsaturated sites,and reduce the reaction energy barrier.Experimental and theoretical calculations demonstrate that strong heterogeneous interfacial bonding interactions between B-TCT and MoSe_(2)can dramatically reduce the free energy of hydrogen adsorption and facilitate efficient interfacial charge migration,thus essentially improving the HER kinetics.We used this 3D porous nanohybrid system assembled by defectrich lamellar structures to elucidate the advantageous synergistic effects of multiple mechanisms among defect structure,heteroatom functionalization,and interfacial coupling,which provided important insights for the development of efficient hybridtype catalysts.
文摘Subject Code:H06 With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Zou Weiguo(邹卫国)from the Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences,CAS demonstrates that E3ligase SMURF2maintains bone
