A systematic calculation of the potential curves or surfaces for 1,2-shift has been realized by using MNDO or other models in MOPAC programs. By referring to the previous author’ viewpoints, the 1,2-shift can be divi...A systematic calculation of the potential curves or surfaces for 1,2-shift has been realized by using MNDO or other models in MOPAC programs. By referring to the previous author’ viewpoints, the 1,2-shift can be divided into two categories. 1,2-electron-deficient shift is that the electronic configuration of the atom which accepts the migrating group is a cation or an electron-deficient atom, and 1,2-anion shift is the one that the accepted atom of the migration group is a negative ion. In terms of the experimental facts and the calculation of the potential surfaces, in electron-deficient shift such as Beckmann or Baeyer-Villiger rearrangement, the migration occurs through a transition complex formed between the π-bond and the cation or electron-deficient migrating group, but in anion shift such as Wittig or Stevens rearrangement, the electron pair in π-orbit excites at first to π orbit, and then the migration occurs through the new formed complex between the anion migration group and the vacant π orbit. The above mechanisms explain reasonably the intramolecular properties, the configuration retentions of the migration group, and the corresponding migratory aptitudes of the two type 1, 2-shifts. The partial and less important free radical reaction of 1, 2-anion shift has been explained by the π-complex mechanism too.展开更多
The single crystals of the azo copper（Ⅱ）-complex have been obtained from the solution of the compound dissolved in the ethanol by slow evaporation at room temperature. The structure was successfully determined by s...The single crystals of the azo copper（Ⅱ）-complex have been obtained from the solution of the compound dissolved in the ethanol by slow evaporation at room temperature. The structure was successfully determined by single-crystal X-ray diffraction. The crystal is of triclinic system, space group P1 with a = 7.8843（12）, b = 11.5998（17）, c = 13.955（2） A, α = 112.214（2）, β = 95.105（2）, γ = 97.616（2）o, V = 1157.6（3） A^3, Mr = 586.97, Z = 2, F（000） = 600, Dc = 1.684 g/cm^3, μ（MoKα） = 1.120 mm-1, the final R = 0.0419 and wR = 0.1259 for 3475 observed reflections with I 〉 2σ（I）. The coordination around copper（II） atom is a slightly distorted square-pyramidal geometry involving [Cu（C16H11N4O8S）（OH）H2O]-cation, one Na＋ anion and one C2H5OH solvate molecule. The hydrogen bonds and π···π stacking interactions extend the complex into a three-dimensional framework.展开更多
Aggregation behavior of 5,10,15-tris(pentafluorophenyl)corrole (F15TPC), 5,10,15,20-tetra(pentafluoroph-enyl)porphyrin (F20TPP), and their copper complexes in DCM solution were investigated by using UV-Vis spectro-sco...Aggregation behavior of 5,10,15-tris(pentafluorophenyl)corrole (F15TPC), 5,10,15,20-tetra(pentafluoroph-enyl)porphyrin (F20TPP), and their copper complexes in DCM solution were investigated by using UV-Vis spectro-scopic method. F20TPP and F20TPPCu exhibited strong π-π stacking interactions in DCM, and the intermolecular dimerization constants turned out to be 1.82 × 103 and 17.2 × 103 L·mol-1 respectively. However, extinction coefficients of F15TPC and F15TPCCu at soret band remained unchanged with increasing in their concentrations from 1.0 to 40.0 μmol·L-1, indicating they remained monomeric in DCM solution. Based on DFT calculation and the π-π stacking geometries observed in crystal structures of metal octaethylcorrole complexes, destroy of π-π interactions in F15TPC and F15TPCCu may be understood by the electrostatic potential surfaces (EPS) features of the molecules and steric repulsions caused by the introducing of three phenyl at the meso- positions of corrole macrocycle.展开更多
A novel cadmium(Ⅱ) isothiocyanate complex [Cd(N-MeIM)2(SCN)2]n (N-MeIM=N-methylimidazole) has been prepared and characterized by spectroscopic analysis and crystallographic method. The title compound crystallize in t...A novel cadmium(Ⅱ) isothiocyanate complex [Cd(N-MeIM)2(SCN)2]n (N-MeIM=N-methylimidazole) has been prepared and characterized by spectroscopic analysis and crystallographic method. The title compound crystallize in the Triclinic system, space group P1, with lattice parameters a=0.589 50(12) nm, b=0.785 70(16) nm, c=0.882 00(18) nm, α=110.98(3)°, β=106.49(3)°, γ=95.08(3)°, and Z=1. The title compound exhibits an infinite chain structure in which each pair of Cd atoms is bridged by two η-1,3-SCN- groups. The unique Cd atom lies on an inversion centre and the coordination sphere is completed by two N-MeIM N atoms to form a CdS2N4 octahedron. The polymeric chains are further extended into three-dimensional network via π...π stackings interactions between the imidazole rings. The cyclic voltammetry behaviors of the compound on glass carbon electrode showed a typical irreversible process. CCDC: 265283.展开更多
The title complex was synthesized by reaction of 2,2′-bipyridine(bipy) and zinc sulfate heptahrdrate in water-methanol solution.The crystal structure was determined by elemental analysis and X-ray diffraction.The res...The title complex was synthesized by reaction of 2,2′-bipyridine(bipy) and zinc sulfate heptahrdrate in water-methanol solution.The crystal structure was determined by elemental analysis and X-ray diffraction.The results show that the title complex belongs to monoclinic system with space group Cc and cell parameter: a = 1.5420(2) nm,b = 1.2696(2) nm,c = 0.6704(1) nm.β= 102.178(2)°.V = 1.2830(3) nm3,Z = 4,Dc = 1.831 g/cm3,μ= 2.104 mm-1,F(000) = 720.The Zn(Ⅱ) is coordinated by one bipy,two water molecules and one SO42-.At the same time,the Zn(Ⅱ) formed a distorted tetrasquare pyramid structure.The complex formed 1D straight chain by SO42-anion,and 1D chain assembled into double-stranded chain by π-π stacking interactions(ca:0.335(1) nm),furthmore,double-stranded chain extended to 2D network by O-H…O hrdrogen bonds,2D network constructed 3D supramolecular structure by C-H…O hrdrogen bonds.展开更多
Removal of carbonyl sulfide(COS) from CO2 stream is significant for the production and utilization of food grade CO2. This study investigates the adsorption performance of Ag/NaZSM-5 as adsorbent prepared by incipient...Removal of carbonyl sulfide(COS) from CO2 stream is significant for the production and utilization of food grade CO2. This study investigates the adsorption performance of Ag/NaZSM-5 as adsorbent prepared by incipient wetness impregnation for the removal of COS from a CO2 stream in a fixed-bed adsorption apparatus. Effects of various conditions on the preparation of adsorbent, adsorption and desorption were intensively examined. The results revealed that COS can be removed to below 1×10-9from a CO2stream(1000 ppm COS/CO2) using Ag/NaZSM-5(10 wt% AgNO3) with an adsorption capacity of 12.86 mg·g-1. The adsorbent can be fully regenerated using hot air at 450 C. The adsorption ability remained stable even after eight cycles of regeneration.展开更多
文摘A systematic calculation of the potential curves or surfaces for 1,2-shift has been realized by using MNDO or other models in MOPAC programs. By referring to the previous author’ viewpoints, the 1,2-shift can be divided into two categories. 1,2-electron-deficient shift is that the electronic configuration of the atom which accepts the migrating group is a cation or an electron-deficient atom, and 1,2-anion shift is the one that the accepted atom of the migration group is a negative ion. In terms of the experimental facts and the calculation of the potential surfaces, in electron-deficient shift such as Beckmann or Baeyer-Villiger rearrangement, the migration occurs through a transition complex formed between the π-bond and the cation or electron-deficient migrating group, but in anion shift such as Wittig or Stevens rearrangement, the electron pair in π-orbit excites at first to π orbit, and then the migration occurs through the new formed complex between the anion migration group and the vacant π orbit. The above mechanisms explain reasonably the intramolecular properties, the configuration retentions of the migration group, and the corresponding migratory aptitudes of the two type 1, 2-shifts. The partial and less important free radical reaction of 1, 2-anion shift has been explained by the π-complex mechanism too.
基金supported by the University Technology Development Project of Shanxi Province (No. 20101116)
文摘The single crystals of the azo copper（Ⅱ）-complex have been obtained from the solution of the compound dissolved in the ethanol by slow evaporation at room temperature. The structure was successfully determined by single-crystal X-ray diffraction. The crystal is of triclinic system, space group P1 with a = 7.8843（12）, b = 11.5998（17）, c = 13.955（2） A, α = 112.214（2）, β = 95.105（2）, γ = 97.616（2）o, V = 1157.6（3） A^3, Mr = 586.97, Z = 2, F（000） = 600, Dc = 1.684 g/cm^3, μ（MoKα） = 1.120 mm-1, the final R = 0.0419 and wR = 0.1259 for 3475 observed reflections with I 〉 2σ（I）. The coordination around copper（II） atom is a slightly distorted square-pyramidal geometry involving [Cu（C16H11N4O8S）（OH）H2O]-cation, one Na＋ anion and one C2H5OH solvate molecule. The hydrogen bonds and π···π stacking interactions extend the complex into a three-dimensional framework.
基金upported by the National Natural Science Foundation of China(20976077,21076100)National Key Basic Research Program of China(973)(2007CB216403)+1 种基金China National Petroleum Corporation(10-01A-01-01-01)Innovation Team of Liaoning Province Colleges,China~~
文摘Aggregation behavior of 5,10,15-tris(pentafluorophenyl)corrole (F15TPC), 5,10,15,20-tetra(pentafluoroph-enyl)porphyrin (F20TPP), and their copper complexes in DCM solution were investigated by using UV-Vis spectro-scopic method. F20TPP and F20TPPCu exhibited strong π-π stacking interactions in DCM, and the intermolecular dimerization constants turned out to be 1.82 × 103 and 17.2 × 103 L·mol-1 respectively. However, extinction coefficients of F15TPC and F15TPCCu at soret band remained unchanged with increasing in their concentrations from 1.0 to 40.0 μmol·L-1, indicating they remained monomeric in DCM solution. Based on DFT calculation and the π-π stacking geometries observed in crystal structures of metal octaethylcorrole complexes, destroy of π-π interactions in F15TPC and F15TPCCu may be understood by the electrostatic potential surfaces (EPS) features of the molecules and steric repulsions caused by the introducing of three phenyl at the meso- positions of corrole macrocycle.
文摘A novel cadmium(Ⅱ) isothiocyanate complex [Cd(N-MeIM)2(SCN)2]n (N-MeIM=N-methylimidazole) has been prepared and characterized by spectroscopic analysis and crystallographic method. The title compound crystallize in the Triclinic system, space group P1, with lattice parameters a=0.589 50(12) nm, b=0.785 70(16) nm, c=0.882 00(18) nm, α=110.98(3)°, β=106.49(3)°, γ=95.08(3)°, and Z=1. The title compound exhibits an infinite chain structure in which each pair of Cd atoms is bridged by two η-1,3-SCN- groups. The unique Cd atom lies on an inversion centre and the coordination sphere is completed by two N-MeIM N atoms to form a CdS2N4 octahedron. The polymeric chains are further extended into three-dimensional network via π...π stackings interactions between the imidazole rings. The cyclic voltammetry behaviors of the compound on glass carbon electrode showed a typical irreversible process. CCDC: 265283.
文摘The title complex was synthesized by reaction of 2,2′-bipyridine(bipy) and zinc sulfate heptahrdrate in water-methanol solution.The crystal structure was determined by elemental analysis and X-ray diffraction.The results show that the title complex belongs to monoclinic system with space group Cc and cell parameter: a = 1.5420(2) nm,b = 1.2696(2) nm,c = 0.6704(1) nm.β= 102.178(2)°.V = 1.2830(3) nm3,Z = 4,Dc = 1.831 g/cm3,μ= 2.104 mm-1,F(000) = 720.The Zn(Ⅱ) is coordinated by one bipy,two water molecules and one SO42-.At the same time,the Zn(Ⅱ) formed a distorted tetrasquare pyramid structure.The complex formed 1D straight chain by SO42-anion,and 1D chain assembled into double-stranded chain by π-π stacking interactions(ca:0.335(1) nm),furthmore,double-stranded chain extended to 2D network by O-H…O hrdrogen bonds,2D network constructed 3D supramolecular structure by C-H…O hrdrogen bonds.
文摘Removal of carbonyl sulfide(COS) from CO2 stream is significant for the production and utilization of food grade CO2. This study investigates the adsorption performance of Ag/NaZSM-5 as adsorbent prepared by incipient wetness impregnation for the removal of COS from a CO2 stream in a fixed-bed adsorption apparatus. Effects of various conditions on the preparation of adsorbent, adsorption and desorption were intensively examined. The results revealed that COS can be removed to below 1×10-9from a CO2stream(1000 ppm COS/CO2) using Ag/NaZSM-5(10 wt% AgNO3) with an adsorption capacity of 12.86 mg·g-1. The adsorbent can be fully regenerated using hot air at 450 C. The adsorption ability remained stable even after eight cycles of regeneration.
