Using density functional theory(DFT) combined with nonequilibrium Green's function investigates the electron-transport properties of several molecular junctions based on the PBTDT-CH=NH molecule, which is modified...Using density functional theory(DFT) combined with nonequilibrium Green's function investigates the electron-transport properties of several molecular junctions based on the PBTDT-CH=NH molecule, which is modified by one to four alkyl groups forming PBTDT-(CH2)nCH=NH. The electronic structures of the isolated molecules(thiol-ended PBTDT-(CH2)nCH=N) have been investigated before the electron-transport calculations are performed. The asymmetric current-voltage characteristics have been obtained for the molecular junctions. Rectifying performance of Au/S-PBTDT-CH=N-S/Au molecular junction can be regulated by introducing alkyl chain. The N3 molecular junction exhibits the best rectifying effect. Its maximum rectifying ratio is 878, which is 80 times more than that of the molecular junction based on the original N molecular junction. The current-voltage(I-V) curves of all the sandwich systems in this work are illustrated by transmission spectra and molecular projection density analysis.展开更多
The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green＇s function formalism. Our c...The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green＇s function formalism. Our calculations show that oligosilanes doped by the phenyl and -C10H6 groups demonstrate better rectifying effect and their rectification ratios are up to 15.41 and 65.13 for their molecular junctions. The current-voltage （I-V） curves of all the Au/ modified oligosilane/Au systems in this work are illustrated by frontier molecular orbitals, transmission spectra and density of states under zero bias. And their rectifying behaviors are analyzed through transmission spectra.展开更多
The title complex, [Mn3（μ-oxalate）3（μ-4,4′-bpy）2（4,4′-bpy）2]n, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in the monoclinic, space group P2 1/c with a = 16.3222...The title complex, [Mn3（μ-oxalate）3（μ-4,4′-bpy）2（4,4′-bpy）2]n, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in the monoclinic, space group P2 1/c with a = 16.3222（6）, b = 16.2594（5）, c = 16.4885（5） A, β = 94.9900（10）°, V= 4359.3（2） A^3, Z = 4, Mn3C46N8O12H32, Mr = 1053.62, Dc = 1.605 g/cm^3, F（000） = 2140 and μ（MoKa） = 0.932 mm^-1. The structure was refined to R = 0.0578 and wR = 0.1061 for 4795 observed reflections （I 〉 2σ（I））. The oxalate anions behave as the bridging ligand and link two manganese atoms repeatedly to form infinite one-dimensional chains which further extend into a two-dimensional network by bridging 4,4′-bpy ligands.展开更多
A new compound, [H2N（CH3）2]2[Zn（btec）]H20 （1, H4btec = 1,2,4,5-benzenetetra- carboxylic acid） has been solvothermally synthesized and structurally characterized by single- crystal X-ray diffraction. The crystal ...A new compound, [H2N（CH3）2]2[Zn（btec）]H20 （1, H4btec = 1,2,4,5-benzenetetra- carboxylic acid） has been solvothermally synthesized and structurally characterized by single- crystal X-ray diffraction. The crystal structure is of monoclinic, space group P21/c with a = 9.5741（3）, b = 14.5044（4）, c = 13.7329（5） A,β = 100.582（4）°, V = 1874.61（10） As, C14H20N2O9Zn, Mr = 425.7, Z = 4, Dc = 1.387 g/cm3,μ = 1.349 mm^-1, F（000） = 776, R = 0.0560 and wR = 0.1684 for 2834 observed reflections （1 〉 2a（I））. Compound 1 based onμ4-btec and tetrahedral building unit features a three-dimensional （3D） anionic framework with mixed connected nou topology. The luminescent property and thermogravimetric analysis of compound 1 are investigated.展开更多
The title complex, {[Cu2（4,4＇-bipyridine）2（μ-O2CMe）2（O2CMe）2],H2O}n 1, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in monoclinic, space group C2/c with a = 13.4474...The title complex, {[Cu2（4,4＇-bipyridine）2（μ-O2CMe）2（O2CMe）2],H2O}n 1, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in monoclinic, space group C2/c with a = 13.4474（5）, b = 11.7566（2）, c = 19.5380（6）A, β = 92.930（2）°, V = 3084.84（16） A^3, Z = 4, Cu2C28N409H30, Mr = 693.64, Dc = 1.494 g/cm^3, F（000） = 1424 and μ（MoKα） = 1.436 mm^-1. With the use of 2062 observed reflections （I 〉 2σ（I））, the structure was refined to R = 0.0769 and wR = 0.2154. In complex 1, the dimeric copper acetate units are linked through 4,4’-bipyridine to yield ID molecular ladders. These ladders are connected via O-H…O hydrogen bonds to generate 2D layers, which are further linked through C-H…O hydrogen bonds to give a 3D supramolecular network.展开更多
基金supported by the National Natural Science Foundation of China(21401023)
文摘Using density functional theory(DFT) combined with nonequilibrium Green's function investigates the electron-transport properties of several molecular junctions based on the PBTDT-CH=NH molecule, which is modified by one to four alkyl groups forming PBTDT-(CH2)nCH=NH. The electronic structures of the isolated molecules(thiol-ended PBTDT-(CH2)nCH=N) have been investigated before the electron-transport calculations are performed. The asymmetric current-voltage characteristics have been obtained for the molecular junctions. Rectifying performance of Au/S-PBTDT-CH=N-S/Au molecular junction can be regulated by introducing alkyl chain. The N3 molecular junction exhibits the best rectifying effect. Its maximum rectifying ratio is 878, which is 80 times more than that of the molecular junction based on the original N molecular junction. The current-voltage(I-V) curves of all the sandwich systems in this work are illustrated by transmission spectra and molecular projection density analysis.
基金supported by National Natural Science Foundation of China(21401023 and 21203027)Cultivating Fund for Excellent Young Scholar of Fujian Normal University(FJSDJK2012063)Program for Innovative Research Team in Science and Technology in Fujian Province University(IRTSTFJ)
文摘The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green＇s function formalism. Our calculations show that oligosilanes doped by the phenyl and -C10H6 groups demonstrate better rectifying effect and their rectification ratios are up to 15.41 and 65.13 for their molecular junctions. The current-voltage （I-V） curves of all the Au/ modified oligosilane/Au systems in this work are illustrated by frontier molecular orbitals, transmission spectra and density of states under zero bias. And their rectifying behaviors are analyzed through transmission spectra.
文摘The title complex, [Mn3（μ-oxalate）3（μ-4,4′-bpy）2（4,4′-bpy）2]n, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in the monoclinic, space group P2 1/c with a = 16.3222（6）, b = 16.2594（5）, c = 16.4885（5） A, β = 94.9900（10）°, V= 4359.3（2） A^3, Z = 4, Mn3C46N8O12H32, Mr = 1053.62, Dc = 1.605 g/cm^3, F（000） = 2140 and μ（MoKa） = 0.932 mm^-1. The structure was refined to R = 0.0578 and wR = 0.1061 for 4795 observed reflections （I 〉 2σ（I））. The oxalate anions behave as the bridging ligand and link two manganese atoms repeatedly to form infinite one-dimensional chains which further extend into a two-dimensional network by bridging 4,4′-bpy ligands.
基金supported by the National Natural Science Foundation of China(21401023 and 21374017)Cultivating Fund for Excellent Young Scholar of Fujian Normal University(FJSDJK2012063)Program for Innovative Research Team in Science and Technology in Fujian Province University(IRTSTFJ)
文摘A new compound, [H2N（CH3）2]2[Zn（btec）]H20 （1, H4btec = 1,2,4,5-benzenetetra- carboxylic acid） has been solvothermally synthesized and structurally characterized by single- crystal X-ray diffraction. The crystal structure is of monoclinic, space group P21/c with a = 9.5741（3）, b = 14.5044（4）, c = 13.7329（5） A,β = 100.582（4）°, V = 1874.61（10） As, C14H20N2O9Zn, Mr = 425.7, Z = 4, Dc = 1.387 g/cm3,μ = 1.349 mm^-1, F（000） = 776, R = 0.0560 and wR = 0.1684 for 2834 observed reflections （1 〉 2a（I））. Compound 1 based onμ4-btec and tetrahedral building unit features a three-dimensional （3D） anionic framework with mixed connected nou topology. The luminescent property and thermogravimetric analysis of compound 1 are investigated.
基金This work was supported by the Science Foundation of Fujian Provincial Key Laboratory of Polymer Materials
文摘The title complex, {[Cu2（4,4＇-bipyridine）2（μ-O2CMe）2（O2CMe）2],H2O}n 1, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in monoclinic, space group C2/c with a = 13.4474（5）, b = 11.7566（2）, c = 19.5380（6）A, β = 92.930（2）°, V = 3084.84（16） A^3, Z = 4, Cu2C28N409H30, Mr = 693.64, Dc = 1.494 g/cm^3, F（000） = 1424 and μ（MoKα） = 1.436 mm^-1. With the use of 2062 observed reflections （I 〉 2σ（I））, the structure was refined to R = 0.0769 and wR = 0.2154. In complex 1, the dimeric copper acetate units are linked through 4,4’-bipyridine to yield ID molecular ladders. These ladders are connected via O-H…O hydrogen bonds to generate 2D layers, which are further linked through C-H…O hydrogen bonds to give a 3D supramolecular network.
