The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl...The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl·2THF with NaH in THF reacts with unsaturated carbonyl compounds to give the corresponding reduction products with a high selectivity. The carbonyl groups have been reduced while the carbon-carbon double bonds are not affected.展开更多
The crystallographic structure and intrinsic magnetic properties have been investigated in the RTiFe_(11), RTiCo_(11) and RTi(Fe_(1-X)Ni_X)_(11) compounds,where R represents Nd,Sm,Gd,Tb,Dy,Ho,Er and Y.Neutron diffract...The crystallographic structure and intrinsic magnetic properties have been investigated in the RTiFe_(11), RTiCo_(11) and RTi(Fe_(1-X)Ni_X)_(11) compounds,where R represents Nd,Sm,Gd,Tb,Dy,Ho,Er and Y.Neutron diffraction and Mossbauer spectra analyses have been used to study the nuclear and magnetic structure of these compounds.the Fe,Co,Ni and Ti atoms are found to exhibit strong site preference with f and j sites fa- voring Fe,Co and Ni atoms and the i site Ti atoms.Two different types of magnetic behavior were observed in the RTiFe_(11) and RTiCo_(11) compounds.In the former,the interatomic distance and the number of nearest neighbor atoms play essential roles.In particular,anomalous thermal expansion behavior is presented in RTiFe_(11).In the latter,the magnetic properties are essentially determined by the modification of the cobalt electronic configuration brought about by the transfer of rare earth conduction electrons to the transition 3d band.The saturation magnetization,Curie temperature and magnetocrystalline anisotropy data of RTiFe_(11), RTiCo_(11)and YTi(Fe_(1-X)Ni_X)_(11)are presented.A tempt to improve the intrinsic magnetic properties in RTiFe_(11)has been made,and the results are reported.On the basis of the crystalline field theory by using a single-ion model,the anisotropy constants and their temperature dependence of the R ions have been calcu- lated,which helps explain the spin reorientation observed in RTiFe_(11).展开更多
A dinuclear complex [DyFe(CN)6(DMF)4(H2O)3]·1.25H2O (DMF=N, N dimethylformamide) 1 based on the cyanide as linkage was prepared and structurally characterized by X ray single crystal structure analysis. The Dy?io...A dinuclear complex [DyFe(CN)6(DMF)4(H2O)3]·1.25H2O (DMF=N, N dimethylformamide) 1 based on the cyanide as linkage was prepared and structurally characterized by X ray single crystal structure analysis. The Dy?ion is eight coordinations in a square antiprism arrangement and the Fe?ion is six coordinations oriented octahedrally. The neutral units [DyFe(CN)6(DMF)4(H2O)3] are held together by hydrogen bonds formed by lattice water molecules, coordinated water molecules and nitrogen atoms of cyanide coming from other distinct complex units to afford a three dimensional framework. CCDC: 192314.展开更多
Thermodynamic models for molecular-beam epitaxy（MBE） growth of ternary Ⅲ-Ⅴ semiconductor materials are proposed.These models are in agreement with our experimental materials InGaP/GaAs and InGaAs/InP,and reported ...Thermodynamic models for molecular-beam epitaxy（MBE） growth of ternary Ⅲ-Ⅴ semiconductor materials are proposed.These models are in agreement with our experimental materials InGaP/GaAs and InGaAs/InP,and reported GaAsP/GaAs and InAsP/InP in thermodynamic growth.The lattice strain energy △G and thermal decomposition sensitive to growth temperature are demonstrated in the models simultaneously.△G is the function of the alloy composition,which is affected by flux ratio and growth temperature directly.The calculation results reveal that flux ratio and growth temperature mainly influence the growth process.Thermodynamic model of quaternary InGaAsP/GaAs semiconductor material is discussed also.展开更多
The construction of N-fused polycyclic compounds at room temperature via the combination of transition-metal catalyst and photocatalyst has been reported.This novel work has successfully realized LED irradiated C—H a...The construction of N-fused polycyclic compounds at room temperature via the combination of transition-metal catalyst and photocatalyst has been reported.This novel work has successfully realized LED irradiated C—H activation of iodonium ylides.The strategy shows wide substrate scope and ideal functional group tolerance.Our work would be useful for the construction of various heterocyclic compounds.展开更多
Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ...Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.展开更多
以N-乙基-3-吲哚三氟甲基β-二酮(EIFD)为主配体,分别以乙二醇单甲醚(EM)、乙二醇二甲醚(EDM)、二缩三乙二醇(TEG)为辅助配体,与DyCl3·6H2O反应合成了一系列Dy(Ⅲ)配合物[Dy(EIFD)3(EM)]·CH2Cl2(1)、[Dy(EIFD)3(EDM)]·CH...以N-乙基-3-吲哚三氟甲基β-二酮(EIFD)为主配体,分别以乙二醇单甲醚(EM)、乙二醇二甲醚(EDM)、二缩三乙二醇(TEG)为辅助配体,与DyCl3·6H2O反应合成了一系列Dy(Ⅲ)配合物[Dy(EIFD)3(EM)]·CH2Cl2(1)、[Dy(EIFD)3(EDM)]·CH2Cl2(2)和[Dy(EIFD)3(TEG)](3)。X射线单晶衍射分析表明,3个配合物都是八配位的单核结构,配位构型分别为双帽三棱柱、正十二面体和双帽三棱柱,分别具有C2v、D2d和C2v对称性。磁学性质显示了配合物1~3具有慢弛豫现象,能垒分别为95.1 K (1)、40.5 K (2)、53.8和13.4 K (3),且配合物1和3有明显的蝴蝶状磁滞回线。进一步讨论了配合物中Dy-O键长和含氧辅助配体的电子效应对配合物有效翻转能垒的影响。展开更多
A dinuclear dysprosium（III） compound,[Dy2（μ2-OH）2（QLC）4（1,10-phen）2]·4H2O（1）（QLC-= 2-quinolinecarboxylate and 1,10-phen = 1,10-phenanthroline）,was synthesized and structurally and magnetically charac...A dinuclear dysprosium（III） compound,[Dy2（μ2-OH）2（QLC）4（1,10-phen）2]·4H2O（1）（QLC-= 2-quinolinecarboxylate and 1,10-phen = 1,10-phenanthroline）,was synthesized and structurally and magnetically characterized.Compound 1 crystallizes in triclinic system,space group P1 with a = 10.9439（3）,b = 11.2823（3）,c = 12.2323（4） ？,α = 107.446（3）,β = 91.700（3）,γ = 91.511（2）°,V = 1439.25（8） A3,Z = 1,C（64）H（50）N8O（14）Dy2,Mr = 1480.12,Dc = 1.708 g/cm3,μ = 2.653 mm-1 and F（000） = 734.The final R = 0.0366 and w R = 0.0736 for 5816 observed reflections with I 〉 2σ（I）.Compound 1 contains the mononuclear [Dy（QLC）2（1,10-phen）] subunit formed from one 1,10-phen and two QLC-ligands chelating Dy（III） ion.Two mononuclear [Dy（QLC）2（1,10-phen）] subunits are bridged by a pair of μ2-OH groups to give a centrosymmetric dinuclear [Dy2（μ2-OH）2（QLC）4（1,10-phen）2] with each Dy（III） ion being eight-coordinated.Detailed susceptibility measurements revealed that compound 1 does not show slow magnetic relaxation under zero direct-current field but exhibits field-induced slow magnetic relaxation under 2 kOe applied field.展开更多
The structure and magnetic properties of Dy2AlFe12Mn4 compound have been investigated by means of X-ray diffraction and magnetization measurements. The Dy2AlFe12Mn4 compound has a hexagonal Th2Ni17-type structure. Neg...The structure and magnetic properties of Dy2AlFe12Mn4 compound have been investigated by means of X-ray diffraction and magnetization measurements. The Dy2AlFe12Mn4 compound has a hexagonal Th2Ni17-type structure. Negative thermal expansion was found in Dy2AlFe12Mn4 compound from 229 to 280 K by X-ray dilatometry. The coefficient of the average thermal expansion is α^- =-3.8×10^-5 K^-1. The magnetostrictive deformations from 105 to 270 K have been calculated by means of the differences between the experimental values of the lattice parameters and the corresponding values extrapolated from the paramagnetic range. The result shows that the spontaneous volume magnetostrictive deformation ωs decreases from 6.2 × 10^-3 to near zero with the temperature increasing from 105 to 270 K, the spontaneous linear magnetostrictive deformation λc along the c axis is much larger than the spontaneous linear magnetostrictive deformation λa in basal-plane at the same temperature except close to 249 K.展开更多
A novel Dy^（3＋） coordination compound,（H_2pipz）（H_3O）[Dy（pydc）_3]·11H_2O（1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid）,has been hydrothermally synthesized and characterized by X-ray...A novel Dy^（3＋） coordination compound,（H_2pipz）（H_3O）[Dy（pydc）_3]·11H_2O（1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid）,has been hydrothermally synthesized and characterized by X-ray single-crystal diffraction,elemental analysis. It is interesting that the packing structure of compound 1 contains 22-core water clusters. Compound 1 is extended into a threedimensional supramolecular structure via O···H···O hydrogen bonding interactions. Furthermore,the luminescent property of compound 1 was also investigated.展开更多
Structural, thermal expansion, and magnetic properties of the Dy_2Fe_(16)Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_(16)Cr compound has a hexagonal Th_2Ni_(17...Structural, thermal expansion, and magnetic properties of the Dy_2Fe_(16)Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_(16)Cr compound has a hexagonal Th_2Ni_(17)-type structure. There exists a negative thermal expansion resulting from a strong spontaneous magnetostriction in the magnetic state of the Dy_2Fe_(16)Cr compound. The average thermal expansion coefficient is-0.794 × 10^(-5)/K in the temperature range 292–407 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed.展开更多
Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran der...Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.展开更多
The structure and magnetic properties of Dy2AlFe14Mn2 compound were investigated by X-ray diffractometry and magnetization measurements.Dy2AlFe14Mn2 compound has a hexagonal Th2Ni17-type structure.Zero thermal expansi...The structure and magnetic properties of Dy2AlFe14Mn2 compound were investigated by X-ray diffractometry and magnetization measurements.Dy2AlFe14Mn2 compound has a hexagonal Th2Ni17-type structure.Zero thermal expansion and negative thermal expansion were found in Dy2AlFe14Mn2 compound in the temperature range from 184 to 264 K,and from 264 to 383 K,respectively,by X-ray dilatometry.The spontaneous magnetostrictive deformations from 104 to 400 K were calculated.The results show that the spontaneous volume magnetostrictive deformation increases firstly with increasing temperature,and then decreases with further increasing temperature.展开更多
DyTiFe_(11) compound is a ferromagnetic substance.It has tetragonal body-centered ThMn_(12)-type crystallographic structure.At room temperature,the easy magnetization direction is the c-axis.A spin reorientation begin...DyTiFe_(11) compound is a ferromagnetic substance.It has tetragonal body-centered ThMn_(12)-type crystallographic structure.At room temperature,the easy magnetization direction is the c-axis.A spin reorientation begins to appear at about 175K.The contribution of Fe sublattice to magnetocrystalline anisotropy was determined by experiments and that of Dy sublattice was obtained by using single ion model calculation.Results show that the spin reorientation arises from the competition of anisotropy between Fe and Dy sublattices.展开更多
文摘The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl·2THF with NaH in THF reacts with unsaturated carbonyl compounds to give the corresponding reduction products with a high selectivity. The carbonyl groups have been reduced while the carbon-carbon double bonds are not affected.
文摘The crystallographic structure and intrinsic magnetic properties have been investigated in the RTiFe_(11), RTiCo_(11) and RTi(Fe_(1-X)Ni_X)_(11) compounds,where R represents Nd,Sm,Gd,Tb,Dy,Ho,Er and Y.Neutron diffraction and Mossbauer spectra analyses have been used to study the nuclear and magnetic structure of these compounds.the Fe,Co,Ni and Ti atoms are found to exhibit strong site preference with f and j sites fa- voring Fe,Co and Ni atoms and the i site Ti atoms.Two different types of magnetic behavior were observed in the RTiFe_(11) and RTiCo_(11) compounds.In the former,the interatomic distance and the number of nearest neighbor atoms play essential roles.In particular,anomalous thermal expansion behavior is presented in RTiFe_(11).In the latter,the magnetic properties are essentially determined by the modification of the cobalt electronic configuration brought about by the transfer of rare earth conduction electrons to the transition 3d band.The saturation magnetization,Curie temperature and magnetocrystalline anisotropy data of RTiFe_(11), RTiCo_(11)and YTi(Fe_(1-X)Ni_X)_(11)are presented.A tempt to improve the intrinsic magnetic properties in RTiFe_(11)has been made,and the results are reported.On the basis of the crystalline field theory by using a single-ion model,the anisotropy constants and their temperature dependence of the R ions have been calcu- lated,which helps explain the spin reorientation observed in RTiFe_(11).
基金supported by the National Natural Science Foundation of China (21271054, 21173060)Major Research Plan of the National Natural Science Foundation of China (91326113, 91226201)Fundamental Research Funds for the Central Universities, China (HEUCF201403001)~~
文摘A dinuclear complex [DyFe(CN)6(DMF)4(H2O)3]·1.25H2O (DMF=N, N dimethylformamide) 1 based on the cyanide as linkage was prepared and structurally characterized by X ray single crystal structure analysis. The Dy?ion is eight coordinations in a square antiprism arrangement and the Fe?ion is six coordinations oriented octahedrally. The neutral units [DyFe(CN)6(DMF)4(H2O)3] are held together by hydrogen bonds formed by lattice water molecules, coordinated water molecules and nitrogen atoms of cyanide coming from other distinct complex units to afford a three dimensional framework. CCDC: 192314.
基金Projects(06YFJZJC01100,08JCYBJC14800)supported by Applied Basic Study Foundation of Tianjin,ChinaProject(2006AA03Z413)supported by the Hi-tech Research and Development Program of China
文摘Thermodynamic models for molecular-beam epitaxy（MBE） growth of ternary Ⅲ-Ⅴ semiconductor materials are proposed.These models are in agreement with our experimental materials InGaP/GaAs and InGaAs/InP,and reported GaAsP/GaAs and InAsP/InP in thermodynamic growth.The lattice strain energy △G and thermal decomposition sensitive to growth temperature are demonstrated in the models simultaneously.△G is the function of the alloy composition,which is affected by flux ratio and growth temperature directly.The calculation results reveal that flux ratio and growth temperature mainly influence the growth process.Thermodynamic model of quaternary InGaAsP/GaAs semiconductor material is discussed also.
基金the support from Sichuan Science and Technology Program(No.2020YJ0221).
文摘The construction of N-fused polycyclic compounds at room temperature via the combination of transition-metal catalyst and photocatalyst has been reported.This novel work has successfully realized LED irradiated C—H activation of iodonium ylides.The strategy shows wide substrate scope and ideal functional group tolerance.Our work would be useful for the construction of various heterocyclic compounds.
文摘Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.
文摘以N-乙基-3-吲哚三氟甲基β-二酮(EIFD)为主配体,分别以乙二醇单甲醚(EM)、乙二醇二甲醚(EDM)、二缩三乙二醇(TEG)为辅助配体,与DyCl3·6H2O反应合成了一系列Dy(Ⅲ)配合物[Dy(EIFD)3(EM)]·CH2Cl2(1)、[Dy(EIFD)3(EDM)]·CH2Cl2(2)和[Dy(EIFD)3(TEG)](3)。X射线单晶衍射分析表明,3个配合物都是八配位的单核结构,配位构型分别为双帽三棱柱、正十二面体和双帽三棱柱,分别具有C2v、D2d和C2v对称性。磁学性质显示了配合物1~3具有慢弛豫现象,能垒分别为95.1 K (1)、40.5 K (2)、53.8和13.4 K (3),且配合物1和3有明显的蝴蝶状磁滞回线。进一步讨论了配合物中Dy-O键长和含氧辅助配体的电子效应对配合物有效翻转能垒的影响。
基金Supported by the National Natural Science Foundation of China(No.21561015)
文摘A dinuclear dysprosium（III） compound,[Dy2（μ2-OH）2（QLC）4（1,10-phen）2]·4H2O（1）（QLC-= 2-quinolinecarboxylate and 1,10-phen = 1,10-phenanthroline）,was synthesized and structurally and magnetically characterized.Compound 1 crystallizes in triclinic system,space group P1 with a = 10.9439（3）,b = 11.2823（3）,c = 12.2323（4） ？,α = 107.446（3）,β = 91.700（3）,γ = 91.511（2）°,V = 1439.25（8） A3,Z = 1,C（64）H（50）N8O（14）Dy2,Mr = 1480.12,Dc = 1.708 g/cm3,μ = 2.653 mm-1 and F（000） = 734.The final R = 0.0366 and w R = 0.0736 for 5816 observed reflections with I 〉 2σ（I）.Compound 1 contains the mononuclear [Dy（QLC）2（1,10-phen）] subunit formed from one 1,10-phen and two QLC-ligands chelating Dy（III） ion.Two mononuclear [Dy（QLC）2（1,10-phen）] subunits are bridged by a pair of μ2-OH groups to give a centrosymmetric dinuclear [Dy2（μ2-OH）2（QLC）4（1,10-phen）2] with each Dy（III） ion being eight-coordinated.Detailed susceptibility measurements revealed that compound 1 does not show slow magnetic relaxation under zero direct-current field but exhibits field-induced slow magnetic relaxation under 2 kOe applied field.
基金This project was financially supported by the National Natural Science Foundation of China (No. 50271022)the Excellent Yong Teachers Program ofMOE of China (No. 1999), and the Natural Science Foundation of Tianjin City (No. 043602011).]
文摘The structure and magnetic properties of Dy2AlFe12Mn4 compound have been investigated by means of X-ray diffraction and magnetization measurements. The Dy2AlFe12Mn4 compound has a hexagonal Th2Ni17-type structure. Negative thermal expansion was found in Dy2AlFe12Mn4 compound from 229 to 280 K by X-ray dilatometry. The coefficient of the average thermal expansion is α^- =-3.8×10^-5 K^-1. The magnetostrictive deformations from 105 to 270 K have been calculated by means of the differences between the experimental values of the lattice parameters and the corresponding values extrapolated from the paramagnetic range. The result shows that the spontaneous volume magnetostrictive deformation ωs decreases from 6.2 × 10^-3 to near zero with the temperature increasing from 105 to 270 K, the spontaneous linear magnetostrictive deformation λc along the c axis is much larger than the spontaneous linear magnetostrictive deformation λa in basal-plane at the same temperature except close to 249 K.
基金financially supported by the Foundation of Fujian Educational Committee(JA14348)
文摘A novel Dy^（3＋） coordination compound,（H_2pipz）（H_3O）[Dy（pydc）_3]·11H_2O（1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid）,has been hydrothermally synthesized and characterized by X-ray single-crystal diffraction,elemental analysis. It is interesting that the packing structure of compound 1 contains 22-core water clusters. Compound 1 is extended into a threedimensional supramolecular structure via O···H···O hydrogen bonding interactions. Furthermore,the luminescent property of compound 1 was also investigated.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50871074 and 61474082
文摘Structural, thermal expansion, and magnetic properties of the Dy_2Fe_(16)Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_(16)Cr compound has a hexagonal Th_2Ni_(17)-type structure. There exists a negative thermal expansion resulting from a strong spontaneous magnetostriction in the magnetic state of the Dy_2Fe_(16)Cr compound. The average thermal expansion coefficient is-0.794 × 10^(-5)/K in the temperature range 292–407 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed.
基金the National Natural Science Foundation of China (No.20676123) for financial support.
文摘Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.
基金Project(50271022) supported by the National Natural Science Foundation of ChinaProject(1999) supported by the Excellent Yong Teachers Program of MOEProject(043602011) supported by the Natural Science Foundation of Tianjin City,China
文摘The structure and magnetic properties of Dy2AlFe14Mn2 compound were investigated by X-ray diffractometry and magnetization measurements.Dy2AlFe14Mn2 compound has a hexagonal Th2Ni17-type structure.Zero thermal expansion and negative thermal expansion were found in Dy2AlFe14Mn2 compound in the temperature range from 184 to 264 K,and from 264 to 383 K,respectively,by X-ray dilatometry.The spontaneous magnetostrictive deformations from 104 to 400 K were calculated.The results show that the spontaneous volume magnetostrictive deformation increases firstly with increasing temperature,and then decreases with further increasing temperature.
文摘DyTiFe_(11) compound is a ferromagnetic substance.It has tetragonal body-centered ThMn_(12)-type crystallographic structure.At room temperature,the easy magnetization direction is the c-axis.A spin reorientation begins to appear at about 175K.The contribution of Fe sublattice to magnetocrystalline anisotropy was determined by experiments and that of Dy sublattice was obtained by using single ion model calculation.Results show that the spin reorientation arises from the competition of anisotropy between Fe and Dy sublattices.
