Two one-dimensional chain-like cyanide-bridged compounds, [Fe（Phen）2（CN）2Ni（Cyclam）]（ClO4）2·DMF-2H2O 1 （Cyclam = 1,4,8,11-tetraaza-cyclotetradecane, Phen = 1,10-phenanthroline, and DMF = N,N-dimethylform...Two one-dimensional chain-like cyanide-bridged compounds, [Fe（Phen）2（CN）2Ni（Cyclam）]（ClO4）2·DMF-2H2O 1 （Cyclam = 1,4,8,11-tetraaza-cyclotetradecane, Phen = 1,10-phenanthroline, and DMF = N,N-dimethylformamide） and [Fe（Phen）2（CN）2Zn（Cyclam）]（PF6）2·CH3CN 2, were prepared by the reaction of [Fe（Phen）2（CN）2]·2H2O with M（Cyclam）^2＋ （M = Ni, Zn）. In complexes 1 and 2, the metal atoms are connected alternatively with CN groups. X-ray structure and IR analyses for 1 and 2 were performed. Structure analysis revealed that both complexes are centrosymmetric and the geometry around each metal atom is an octahedron. The two complexes crystallize in triclinic with space group of P^1-. For 1, a = 10.439（4）, b = 14.976（7）, c = 15.914（8）A,α = 83.168（15）, β = 74.338（15）, γ = 78.023（15）°, V = 2338.3（18）A^3, Z = 2, Mr = 1035.37, Dc = 1.471 g/cm^3, F（000） = 1076,μ = 0.895 mm^-1, the final R = 0.0616 and wR = 0.1414 for 5849 observed reflections （1 〉 2σ（I））. For 2, a = 9.656（6）, b = 15.404（9）, c = 15.822（10）A, α = 78.68（2）, β= 78.917（19）, γ = 77.15（2）°, V = 2223（2）A^3, Z = 2, Mr = 1064.87, Dc = 1.587 g/cm^3, F（000） = 1078,μ = 1.032 mm^-1, the final R = 0.0672 and wR = 0.1595 for 6819 observed reflections （I 〉 2σ（I））.展开更多
A new one-dimensional polymer, [Zn（SC6H4S）（1,3-DPA）]n （1, SC6H4S = 1,4-ben- zenedithiolate and 1,3-DPA = 1,3-diaminepropane）, has been synthesized and characterized by elemental analysis, PXRD, IR spectra, and s...A new one-dimensional polymer, [Zn（SC6H4S）（1,3-DPA）]n （1, SC6H4S = 1,4-ben- zenedithiolate and 1,3-DPA = 1,3-diaminepropane）, has been synthesized and characterized by elemental analysis, PXRD, IR spectra, and single-crystal X-ray diffraction. The complex crystallizes in triclinic system, space group P1, with a = 6.7119（1）, b = 9.0230（2）, c = 10.4943（2） A, a = 69.288（1）, β = 75.848（1）, ）, = 81.513（1）°, V= 575.123（19） A3, Dc = 1.615 g/cm^3, Z = 2, F（000） = 288; the final S = 1.070, R = 0.0234, and wR = 0.0551. The compound consists of an infinite zigzag chain formed by [Zn（1,3-DPA）]^2＋ units joined by SC6H4S ligands. Each chain interacts with neighboring chains via weak N-H…S hydrogen bonds to form an extended three-dimensional （3D） supramolecular network. The thermal and photoluminescent properties of 1 have also been investigated.展开更多
We analytically study the electronic structure and optical properties of zigzag-edged phosphorene nanoribbons(ZPNRs) using the tight-binding Hamiltonian and Kubo formula. By directly solving the discrete Schrodinger e...We analytically study the electronic structure and optical properties of zigzag-edged phosphorene nanoribbons(ZPNRs) using the tight-binding Hamiltonian and Kubo formula. By directly solving the discrete Schrodinger equation, we obtain the energy spectra and wavefunctions for N-ZPNR(where N is the number of transverse zigzag atomic chains) and classify the eigenstates according to the lattice symmetry. Then, we obtain the optical transition selection rule of ZPNRs on the basis of symmetry analysis and analytical expressions of optical transition matrix elements. Under incident light that is linearly polarized along the ribbon, we determine that the optical transition selection rule for N-ZPNR with even-or odd-N is qualitatively different. Specifically, for even-N ZPNRs, the inter-(intra-) band selection rule is ?n =odd(even) because the parity of the wavefunction corresponding to the n-th subband in the conduction(valence) band is(-1)~n[(-1)~((n+1))] owing to the presence of C(2x) symmetry. However, the optical transitions between any subbands are possible owing to the absence of C(2x) symmetry. Our results provide a further understanding on the electronic states and optical properties of ZPNRs, which are useful for explaining the optical experiment data on ZPNR samples.展开更多
Two new heterobimetallic coordination polymers{[Co(NiL)(H2O)3]·4H2O}n(1)and{[Cu(NiL)(H2O)3]·4H2O}n(2)were synthesized based on metalloligand under the same self-assembly conditions.X-ray diffraction analyses...Two new heterobimetallic coordination polymers{[Co(NiL)(H2O)3]·4H2O}n(1)and{[Cu(NiL)(H2O)3]·4H2O}n(2)were synthesized based on metalloligand under the same self-assembly conditions.X-ray diffraction analyses reveal that the two compounds involve close-packed zigzag chains,which expand into various three-dimensional supramolecular frameworks through the second interactions such as hydrogen bonds andπ···πstacking interactions.In these two compounds,NiL as a bridging ligand chelates the metal ion nodes via two oxamido carbonyls and carboxylate oxygen atom.The central Co(Ⅱ)and Cu(Ⅱ)ions in 1 and 2 both exhibit distorted octahedral coordination geometry.They are bridged by macrocyclic oxamido metalloligands fusing the zigzag chains with a‘‘head-to-tail’’arrangement.The Ni(Ⅱ)ion in metalloligand is coordinated by four nitrogen atoms with the[NiN4]chromophore exhibiting distorted planarity.The two investigated compounds were further characterized by thermogravimetric analysis and FT-IR spectroscopy.The fluorescent properties of 1 and 2 in the solid state were also investigated.展开更多
We report a study of the structure and magnetic properties of the S=3/2 zigzag spin chain compound BaCoTe_(2)O_(7).Neutron diffraction measurements show that it crystallizes in the noncentrosymmetric space group Ama2 ...We report a study of the structure and magnetic properties of the S=3/2 zigzag spin chain compound BaCoTe_(2)O_(7).Neutron diffraction measurements show that it crystallizes in the noncentrosymmetric space group Ama2 with a canted↑↑↓↓spin structure along the quasi-one-dimensional zigzag chain and a moment size of 1.89(2)μBat 2 K.Both magnetic susceptibility and specific heat measurements yield an antiferromagnetic phase transition at TN=6.2 K.A negative Curie-Weiss temperature,ΘCW=-74.7(2) K,and an empirical frustration parameter,f=|ΘCW|/TN≈12,are obtained by fitting the magnetic susceptibility,indicating antiferromagnetic interactions and strong magnetic frustration.From ultraviolet-visible absorption spectroscopy and first-principles calculations,an indirect band gap of 2.68(2) eV is determined.We propose that the canted zigzag spin chain of BaCoTe_(2)O_(7) may produce a change in the polarization via the exchange-striction mechanism.展开更多
A new imidazolium compound, C15H17N4ClO4, was prepared from a flexible bidentate ligand of 1,3-di(imidazol-1-ylmethyl)-5-methylbenzene, and characterized by X-ray analysis. It is of orthorhombic, space group Pnma with...A new imidazolium compound, C15H17N4ClO4, was prepared from a flexible bidentate ligand of 1,3-di(imidazol-1-ylmethyl)-5-methylbenzene, and characterized by X-ray analysis. It is of orthorhombic, space group Pnma with a = 8.182(2), b = 12.874(3), c = 15.611(4) ? V = 1644.4(7) 3, Dc = 1.425 g/cm3, Z = 4, Mr = 352.78, m(MoKa) = 0.944 mm-1, F(000) = 736, S = 1.036, the final R = 0.0521 and wR = 0.1187 for 1128 observed reflections (I > 2s(I)). An infinite one-dimensional zigzag chain is formed by NH…N hydrogen bonding interactions between the imidazolium salt cations.展开更多
基金the grants from 973 Program (2007CB815301 and 2006CB932904)the National Natural Science Foundation of China (20333070 and 20673118)+1 种基金the Science Foundation of CAS (KJCX2-YW-M05)Fujian Province (2006L2005, 2006F3132 and 2007J0171)
文摘Two one-dimensional chain-like cyanide-bridged compounds, [Fe（Phen）2（CN）2Ni（Cyclam）]（ClO4）2·DMF-2H2O 1 （Cyclam = 1,4,8,11-tetraaza-cyclotetradecane, Phen = 1,10-phenanthroline, and DMF = N,N-dimethylformamide） and [Fe（Phen）2（CN）2Zn（Cyclam）]（PF6）2·CH3CN 2, were prepared by the reaction of [Fe（Phen）2（CN）2]·2H2O with M（Cyclam）^2＋ （M = Ni, Zn）. In complexes 1 and 2, the metal atoms are connected alternatively with CN groups. X-ray structure and IR analyses for 1 and 2 were performed. Structure analysis revealed that both complexes are centrosymmetric and the geometry around each metal atom is an octahedron. The two complexes crystallize in triclinic with space group of P^1-. For 1, a = 10.439（4）, b = 14.976（7）, c = 15.914（8）A,α = 83.168（15）, β = 74.338（15）, γ = 78.023（15）°, V = 2338.3（18）A^3, Z = 2, Mr = 1035.37, Dc = 1.471 g/cm^3, F（000） = 1076,μ = 0.895 mm^-1, the final R = 0.0616 and wR = 0.1414 for 5849 observed reflections （1 〉 2σ（I））. For 2, a = 9.656（6）, b = 15.404（9）, c = 15.822（10）A, α = 78.68（2）, β= 78.917（19）, γ = 77.15（2）°, V = 2223（2）A^3, Z = 2, Mr = 1064.87, Dc = 1.587 g/cm^3, F（000） = 1078,μ = 1.032 mm^-1, the final R = 0.0672 and wR = 0.1595 for 6819 observed reflections （I 〉 2σ（I））.
基金Supported by the National Natural Science Foundation of China(No.21301035)
文摘A new one-dimensional polymer, [Zn（SC6H4S）（1,3-DPA）]n （1, SC6H4S = 1,4-ben- zenedithiolate and 1,3-DPA = 1,3-diaminepropane）, has been synthesized and characterized by elemental analysis, PXRD, IR spectra, and single-crystal X-ray diffraction. The complex crystallizes in triclinic system, space group P1, with a = 6.7119（1）, b = 9.0230（2）, c = 10.4943（2） A, a = 69.288（1）, β = 75.848（1）, ）, = 81.513（1）°, V= 575.123（19） A3, Dc = 1.615 g/cm^3, Z = 2, F（000） = 288; the final S = 1.070, R = 0.0234, and wR = 0.0551. The compound consists of an infinite zigzag chain formed by [Zn（1,3-DPA）]^2＋ units joined by SC6H4S ligands. Each chain interacts with neighboring chains via weak N-H…S hydrogen bonds to form an extended three-dimensional （3D） supramolecular network. The thermal and photoluminescent properties of 1 have also been investigated.
基金supported by the National Natural Science Foundation of China(Grant Nos.11804092,11774085,61674145,and 69876039)the Project Funded by China Postdoctoral Science Foundation(Grant Nos.BX20180097,and 2019M652777)the Hunan Provincial Natural Science Foundation of China(Grant No.2019JJ40187)。
文摘We analytically study the electronic structure and optical properties of zigzag-edged phosphorene nanoribbons(ZPNRs) using the tight-binding Hamiltonian and Kubo formula. By directly solving the discrete Schrodinger equation, we obtain the energy spectra and wavefunctions for N-ZPNR(where N is the number of transverse zigzag atomic chains) and classify the eigenstates according to the lattice symmetry. Then, we obtain the optical transition selection rule of ZPNRs on the basis of symmetry analysis and analytical expressions of optical transition matrix elements. Under incident light that is linearly polarized along the ribbon, we determine that the optical transition selection rule for N-ZPNR with even-or odd-N is qualitatively different. Specifically, for even-N ZPNRs, the inter-(intra-) band selection rule is ?n =odd(even) because the parity of the wavefunction corresponding to the n-th subband in the conduction(valence) band is(-1)~n[(-1)~((n+1))] owing to the presence of C(2x) symmetry. However, the optical transitions between any subbands are possible owing to the absence of C(2x) symmetry. Our results provide a further understanding on the electronic states and optical properties of ZPNRs, which are useful for explaining the optical experiment data on ZPNR samples.
基金supported by the Natural Science Foundation of He’nan Educational Committee of China(17A150056)the National Natural Science Foundation of China(21501203)+2 种基金the Funds of Basic and Advanced Technology Research Project of Henan Province of China(192012310497)the Research Fund for the Doctoral Program of Higher Education of China(Zhoukou Normal University,No.ZKNUB2013003)the Funds of Zhoukou Normal University(ZKNUB115202)。
文摘Two new heterobimetallic coordination polymers{[Co(NiL)(H2O)3]·4H2O}n(1)and{[Cu(NiL)(H2O)3]·4H2O}n(2)were synthesized based on metalloligand under the same self-assembly conditions.X-ray diffraction analyses reveal that the two compounds involve close-packed zigzag chains,which expand into various three-dimensional supramolecular frameworks through the second interactions such as hydrogen bonds andπ···πstacking interactions.In these two compounds,NiL as a bridging ligand chelates the metal ion nodes via two oxamido carbonyls and carboxylate oxygen atom.The central Co(Ⅱ)and Cu(Ⅱ)ions in 1 and 2 both exhibit distorted octahedral coordination geometry.They are bridged by macrocyclic oxamido metalloligands fusing the zigzag chains with a‘‘head-to-tail’’arrangement.The Ni(Ⅱ)ion in metalloligand is coordinated by four nitrogen atoms with the[NiN4]chromophore exhibiting distorted planarity.The two investigated compounds were further characterized by thermogravimetric analysis and FT-IR spectroscopy.The fluorescent properties of 1 and 2 in the solid state were also investigated.
基金supported by the National Natural Science Foundation of China(Grant No.11904414)the National Key Research and Development Program of China(Grant No.2019YFA0705702)+3 种基金supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0306001,and 2017YFA0206203)the National Natural Science Foundation of China(Grant No.11974432)the Guangdong Basic and Applied Basic Research Fund(Grant No.2019A1515011337)the Leading Talent Program of Guangdong Special Projects。
文摘We report a study of the structure and magnetic properties of the S=3/2 zigzag spin chain compound BaCoTe_(2)O_(7).Neutron diffraction measurements show that it crystallizes in the noncentrosymmetric space group Ama2 with a canted↑↑↓↓spin structure along the quasi-one-dimensional zigzag chain and a moment size of 1.89(2)μBat 2 K.Both magnetic susceptibility and specific heat measurements yield an antiferromagnetic phase transition at TN=6.2 K.A negative Curie-Weiss temperature,ΘCW=-74.7(2) K,and an empirical frustration parameter,f=|ΘCW|/TN≈12,are obtained by fitting the magnetic susceptibility,indicating antiferromagnetic interactions and strong magnetic frustration.From ultraviolet-visible absorption spectroscopy and first-principles calculations,an indirect band gap of 2.68(2) eV is determined.We propose that the canted zigzag spin chain of BaCoTe_(2)O_(7) may produce a change in the polarization via the exchange-striction mechanism.
基金the Natural Science Foundation of Jiangsu province (Grant No Bk2001031)
文摘A new imidazolium compound, C15H17N4ClO4, was prepared from a flexible bidentate ligand of 1,3-di(imidazol-1-ylmethyl)-5-methylbenzene, and characterized by X-ray analysis. It is of orthorhombic, space group Pnma with a = 8.182(2), b = 12.874(3), c = 15.611(4) ? V = 1644.4(7) 3, Dc = 1.425 g/cm3, Z = 4, Mr = 352.78, m(MoKa) = 0.944 mm-1, F(000) = 736, S = 1.036, the final R = 0.0521 and wR = 0.1187 for 1128 observed reflections (I > 2s(I)). An infinite one-dimensional zigzag chain is formed by NH…N hydrogen bonding interactions between the imidazolium salt cations.
