A new complex [Cd(H2biim)2(H2O)2]·(ino)2·4H2O (H2biim = 2,2'-biimidazole, ino = isonicotinate-N-oxide) has been prepared and characterized by single-crystal X-ray diffraction analysis, IR and fluore...A new complex [Cd(H2biim)2(H2O)2]·(ino)2·4H2O (H2biim = 2,2'-biimidazole, ino = isonicotinate-N-oxide) has been prepared and characterized by single-crystal X-ray diffraction analysis, IR and fluorescence spectra analysis. The crystal is of triclinic system, space group P1 with a = 7.5380(6), b = 8.0402(7), c = 13.5094(11) , α = 104.269(1), β = 93.604(1), γ = 98.349(1)°, V = 780.93(11) 3, Mr = 765.00, Dc = 1.627 g/cm3, F(000) = 390, μ = 0.776 mm-1 and Z = 1. The final R = 0.0322 and wR = 0.0825 for 7038 observed reflections with I 2σ(I) and R = 0.0341 and wR = 0.0832 for all data. The title complex exhibits an infinite chain-like structure through bridging isonicotinate-N-oxide. Strong interchain hydrogen bonds between isonicotinate-N-oxide and H2biim result in the robust 3-D supramolecular architecture. Moreover, the complex shows strong photoluminescence with emission maximum at λ = 401 nm upon λex = 330 nm.展开更多
Under hydrothermal condition, the reaction of 2-naphthoxyacetic acid with ZnCl2 and 4,4′-bipyridine (4,4′-bipy) has afforded a new Zn(Ⅱ) compound, [Zn(C12H9O3)2(C10H8N2)]n·nH2O1, which was structurally...Under hydrothermal condition, the reaction of 2-naphthoxyacetic acid with ZnCl2 and 4,4′-bipyridine (4,4′-bipy) has afforded a new Zn(Ⅱ) compound, [Zn(C12H9O3)2(C10H8N2)]n·nH2O1, which was structurally characterized by single-crystal X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 7.7335(2), b = 19.3834(4), c = 20.1707(4) A, β = 104.9830(10)°, V = 2920.82(11) A^3, C34H28ZnN2O7, Mr = 641.95, Z = 4, Dc = 1.460 g/cm^3,μ = 0.895 mm^-1, F(000) = 1328, R = 0.0406 and wR = 0.0876 for 4417 observed reflections (I〉 2σ(I)) Complex 1 consists of one-dimensional zigzag chains deriving from Zn(C12H9O3)2 units linked by 4,4′-bipy ligands, and lattice water molecules decorate between the chains. Non-covalent interactions, such as hydrogen-bonding and aromatic π-π interactions, lead to the formation of a 3D network structure. The thermogravimetric analysis (TGA) and luminescent property for 1 have also been studied in this paper.展开更多
One binuclear sodium(Ⅰ) complex [Na2(2-benzoylbenzoato)4(Phen)2(H2O)2]·H2O has been synthesized with 2-benzoylbenzoic acid and 1,10-henanthroline as ligands. The crystal structure was determined by X-ray...One binuclear sodium(Ⅰ) complex [Na2(2-benzoylbenzoato)4(Phen)2(H2O)2]·H2O has been synthesized with 2-benzoylbenzoic acid and 1,10-henanthroline as ligands. The crystal structure was determined by X-ray diffraction. The crystal belongs to the triclinic system with space group P , a = 1.08096(8), b = 1.09619(8), c = 1.09740(8) nm, α = 79.0600(1), β = 71.0450(1), γ = 62.0540(1)o, V = 1.08533(1) nm3, Dc = 1.421 g/cm3, Z = 2, F(000) = 484, GOOF = 1.036, the final R = 0.0363 and wR = 0.0961. The crystal structure shows that two neighboring sodium(Ⅰ) ions are linked together by two bridging water molecules, and each end position is coordinated with one 1,10-phenanthroline molecule and one 2-benzoylbenzoato to form a binuclear structure. Each sodium(Ⅰ) ion in the molecule is coordinated with five atoms to give a distorted trigonal bipyramid. The fluorescence property of the title complex is also discussed.展开更多
A new trinuclear nickel complex,[Ni3(pdc)3(2,2'-bipy)3(H2O)2]·2H2O(H2pdc = pyridine 2,6-dicarboxylic acid,2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized and characterized by IR,elemen...A new trinuclear nickel complex,[Ni3(pdc)3(2,2'-bipy)3(H2O)2]·2H2O(H2pdc = pyridine 2,6-dicarboxylic acid,2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized and characterized by IR,elemental analysis and X-ray diffraction methods.Crystal data for this complex:monoclinic,space group P21/n,a = 21.206(4),b = 10.002(2),c = 28.066(6),β = 108.18(3)°,C51H41N9Ni3O16,Mr = 1212.06,V = 5.656(2) nm3,Dc = 1.423 g·cm-3,μ(MoKα) = 1.062 mm-1,Z = 4,F(000) = 2488,GOOF = 1.034,the final R = 0.0543 and wR = 0.1237 for 6149 observed reflections with Ⅰ 〉 2σ(Ⅰ).In the complex,three nickel(Ⅱ) ions are bridged by the pyridine 2,6-dicarboxylic acid groups,and all nickel(Ⅱ) ions are seven-coordinated by nitrogen atoms of 2,2'-bipyridine and pyridine 2,6-dicarboxylic acid and oxygen atoms from pyridine 2,6-dicarboxylic and water to adopt a severely distorted pentagonal bipyramidal geometry.The emission and excitation peaks of the complex in ethanol solutions are located at 336 and 316 nm,respectively.展开更多
A new ternary neodymium zirconium sulfide Nd_2ZrS_5 was synthesized by high-temperature solid-state reaction and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic spac...A new ternary neodymium zirconium sulfide Nd_2ZrS_5 was synthesized by high-temperature solid-state reaction and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Pnma(No. 62) belonging to the Y_2HfS_5 structure-type with a = 11.461(4), b = 8.009(3), c = 7.315(3) A, Z = 2 and V = 671.5(4)A3. Its structure features NdS_8 and ZrS_7 polyhedra-constructed a 3-D network. The data of magnetic susceptibility indicate its antiferromagnetic-like behavior without magnetic order down to 2 K.展开更多
The reaction of Cd(NO_3)_2·4H_2O with 4,4?-dipyridylacetylene(4,4?-DPA) and 2-nitroterephthalic acid(2-NO_2-H_2BDC) in DMF/H_2O mixed solvent has afforded a compound {[Cd(2-NO_2-BDC)(4,4?-DPA)]·...The reaction of Cd(NO_3)_2·4H_2O with 4,4?-dipyridylacetylene(4,4?-DPA) and 2-nitroterephthalic acid(2-NO_2-H_2BDC) in DMF/H_2O mixed solvent has afforded a compound {[Cd(2-NO_2-BDC)(4,4?-DPA)]·(DMF)}_n(1). Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the monoclinic system, space group P21/n, with a = 12.1488(3), b = 14.6689(3), c = 13.1615(3) ?, β = 111.809(3)o, V = 2177.63(9) ?~3, Z = 4, C_(23)H_(18)N_4O_7 Cd, M_r = 574.81, D_c = 1.753 g/cm^3, μ = 8.523 mm^(-1), F(000) = 1152, the final R = 0.0411 and wR = 0.1064 for 3589 observed reflections with I 〉 2s(I). In compound 1, the Cd(Ⅱ) ions are linked by the carboxylate groups of 2-NO_2-BDC ligands to give a two-dimensional layered structure based on the centrosymmetric dinuclear Cd_2(COO)_2 units, which are further connected by the 4,4?-DPA ligands to produce a three-dimensional framework with pcu topology. Careful examination revealed that compound 1 is a 2-fold interpenetrating framework. Furthermore, the gas adsorption properties of 1 for N_2 and CO_2 have also been investigated.展开更多
α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decrease...α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.展开更多
Two novel supramolecular complexes,[M4L12]·(HPO4)·(PO4)2(L = 2,2'-dibenzi-midazole,M = Co and Ni) were synthesized by the hydrothermal method and characterized by elemental analysis,IR,UV,and TG-TGA,a...Two novel supramolecular complexes,[M4L12]·(HPO4)·(PO4)2(L = 2,2'-dibenzi-midazole,M = Co and Ni) were synthesized by the hydrothermal method and characterized by elemental analysis,IR,UV,and TG-TGA,and the crystal structures were determined by single-crystal X-ray diffraction.The results showed that both of them belong to the cubic system and space group I 4 3d.Crystal parameters of C168H121Co4N48O12P3(1):a = b = c = 2.5104(6) nm,V = 15.820(7) nm3,Mr = 3332.75,Z = 4,Dc = 1.399 Mg/m3,μ = 0.521 mm-1,F(000) = 6852,S = 1.011,the final R = 0.0248 and wR = 0.0663 for 2120 observed reflections(I 2σ(I)) and R = 0.0315 and wR = 0.0706 for all data.Crystal parameters of C168H121Ni4N48O12P3(2):a = b = c = 2.4977(5) nm,V = 15.581(5) nm3,Mr = 3331.87,Z = 4,Dc = 1.420 Mg/m3,μ = 0.587 mm-1,F(000) = 6868,S = 1.074,the final R = 0.0443 and wR = 0.1364 for 1774 observer reflections(I 2σ(I)) and R = 0.0647 and wR = 0.1492 for all data.Each of them consisted of four M(II) cations,twelve 2,2'-dibenzimidazole ligands,one monohydrogen phosphate anion and two phosphate anions in the single cell.The central M(II) cation,coordinated with six alkaline nitrogen atoms from three 2,2'-dibenzimidazole ligands,displayed the expected distorted-octahedral geometry.The 3D supramolecular system was formed by the hydrogen bond N-H...O and π-π stacking interaction between neighboring single cells.Complex 1 showed two irreversible single-electron reduction processes of the central metal ion at-0.06 and-0.42 V in DMF solution.展开更多
The title compound N,N'-bis(5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl) ethylene diamine (DPTDEDA, C12H26N2O4P2S2) was synthesized by the reaction of neopentyl glycol, phosphorus thio-chloride and 1,2-ethylene...The title compound N,N'-bis(5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl) ethylene diamine (DPTDEDA, C12H26N2O4P2S2) was synthesized by the reaction of neopentyl glycol, phosphorus thio-chloride and 1,2-ethylenediamine, and characterized by elemental analysis, IR and ^1H NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction analysis and the thermal property was analyzed by TG analysis. The crystal structure belongs to monoclinic, space group P21/c, with a = 14.557(16), b = 11.299(12), c = 12.163(13)A,β = 98.707(19)^o, Dc = 1.305 g/cm^3, Z = 4, γ = 0.71073A,μ(MoKa) = 0.447 mm^-1, Mr = 388.41, V = 1977(4)A3, F(000) = 824, S = 1.107, the final R = 0.0478 and wR = 0.0810 for 1738 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that the crystal structure is centrosymmetrically distributed through 1,2-ethylenediamine to join two distorted six-membered rings. The weak N-H…S interactions are observed and link the molecules into sheets. TG analysis shows that the title compound has good thermal stability and char-forming capability, which are required for an excellent intumescent fire retardant.展开更多
A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic...A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic, space group Co, a = 14.0133(14), b = 16.0409(16), c = 30.372(3) A, β = 100.8950(10)°, V = 6704.1(12) A3, Dc = 1.364 g/cm3, Z = 8,μ(MoKa) = 0.704 mml, F(000) = 2840, the final R= 0.0552 and wR = 0.1431. In the crystal structure, the whole molecule consists of two copper ions, four 2-benzoylbenzoic acid molecules, two 2,2′-bipyridine molecules and two water molecules. Each central copper ion is coordinated with two nitrogen atoms from one 2,2′-bipyridine molecule and three oxygen atoms from two 2-benzoylbenzoic acids and one water molecule, respectively, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.展开更多
A novel compound 4,8,10-trimethyl-2-(3,5-dimethylpyrazol)-pyrido-[2',3':3,4]-py-razol-[1,5-5-a]-pyrimidine(C17H18N6) has been synthesized from 2,6-dichloro-4-methylnico-tino-nitrile,hydrazine and acetylacetone ...A novel compound 4,8,10-trimethyl-2-(3,5-dimethylpyrazol)-pyrido-[2',3':3,4]-py-razol-[1,5-5-a]-pyrimidine(C17H18N6) has been synthesized from 2,6-dichloro-4-methylnico-tino-nitrile,hydrazine and acetylacetone by substitution and cyclolization.The structure was charac-terized by elemental analysis,1H NMR and IR,and single-crystal structure was determined by X-ray diffraction analysis.The compound crystallizes in the monoclinic system,space group P21/c with a = 8.0338(9),b = 28.618(3),c = 7.2688(8),β = 111.051(2)o,V = 1559.6(3) 3,Z = 4,Dc = 1.305 g/cm3,μ = 0.083 mm-1,Mr = 306.37,F(000) = 648,S = 0.971,the final R = 0.0795 and wR = 0.1746 for 1457 observed reflections(Ⅰ 〉 2σ(Ⅰ)).The results demonstrate that the pyridine,pyrazole and pyrimidine rings are nearly coplanar,which is evident from the dihedral angles among the four rings in the range of 0.13~4.15o.The face-to-face π-π stacking interactions among pyridine,pyrazol and pyrimidine rings result in a supramolecular crystal,in which they seem to be effective in stabilizing the structure.Meanwhile,the fluorescence properties of the title compound were discussed,which showed very strong fluorescence.The calculated results(selected bond lengths,bond angles and torsion angles) are all typical and agree well with the experimental results,which demonstrates that B3LYP/6-31+G* is suitable for the title compound.展开更多
Two alkaline earth metal coordination polymers [M(2-Hstp)(H2O)] (M = Ca2+ (1) and Sr2+ (2), 2-H3stp = 2-sulfoterephthalate) were synthesized under hydrothermal conditions by the precursor [Mn(2-Hstp)2(...Two alkaline earth metal coordination polymers [M(2-Hstp)(H2O)] (M = Ca2+ (1) and Sr2+ (2), 2-H3stp = 2-sulfoterephthalate) were synthesized under hydrothermal conditions by the precursor [Mn(2-Hstp)2(4,4?-Hbpy)2] and alkaline earth metal salts. The two alkaline earth complexes are not isomorphic. Complex 1 crystallizes in the monoclinic space group P21/m, while 2 in the monoclinic space group P21/c, despite of their similar formulas. In 1, the Ca2+ ion lies in a seven-coordinated pentagon bipyramidal configuration, coordinated with five 2-Hstp2- anions and one water molecule. However, the Sr2+ ion in 2 is coordinated by nine oxygen atoms to form a single-capped square antiprism polyhedron. Both 1 and 2 exhibit π-π* emission of the 2-sulfotere- phthalate ligand.展开更多
A new naphthol-based compound 1, C22 H22 N2 O2, has been designed and synthesized. The structure of the title compound 1 was confirmed by IR, 1 H NMR, 13 C NMR, H RMS, and X-ray single-crystal diffraction. The crystal...A new naphthol-based compound 1, C22 H22 N2 O2, has been designed and synthesized. The structure of the title compound 1 was confirmed by IR, 1 H NMR, 13 C NMR, H RMS, and X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/c, with a = 12.888(9), b = 15.543(10), c = 9.119(6) ?, β = 94.05(3)°, V = 1822(2) ?3, Z = 4, Dc = 1.263 g/cm3, Mr = 346.41, μ = 0.081 mm-1, F(000) = 736.0, the final R = 0.0452 and wR = 0.1142 for 3404 observed reflections with(I 〉 2σ(I)). The crystal structure of 1 is stabilized by O–H···N, N–H···O, C–H···O hydrogen bonds and π-π interactions. The spectroscopic studies of 1 toward various metal ions were also investigated in 25%(V/V) ethanol aqueous solution, and the result showed that it can selectively recognize Zn2+ with fluorescence enhancement.展开更多
A benzothiazole-based compound 1, C28H24N4O2S, has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 9.6309(14), b = 15.230(2), c = 1...A benzothiazole-based compound 1, C28H24N4O2S, has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 9.6309(14), b = 15.230(2), c = 17.197(3)A, β = 105.222(2)°, V = 2433.9(6) A^3, Z = 4, F(000) = 1008, Dc = 1.311 Mg/m^3, Mr = 480.57, μ = 0.166 mm^-1, the final R = 0.0509 and wR = 0.1481 for 6643 observed reflections with I 〉 2σ(I). The crystal structure of compound 1 is stabilized by C–H…O, N–H…N, N–H…O, O–H…N and C–H…N hydrogen bonds. The spectroscopic studies of the title compound toward various metal ions were also investigated in 25%(V/V) ethanol aqueous solution, and the result showed that it can selectively recognize Cu^2+ with fluorescence quenching.展开更多
An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and...An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and spectral techniques. 1 belongs to monoclinic, space group P21/c with a = 8.3545(17), b = 10.550(2), c = 12.370(3)A, β = 102.64(3)°, V = 1063.9(4)A3, Mr = 464.64, De= 2.901 g/cm^3, F(000) = 836,μ = 15.710 mm^-1, Z= 4, the final R = 0.0286 and wR = 0.0685 for 10164 observed reflections with Ⅰ 〉 2σ(Ⅰ). 1 presents a two-dimensional layer-like structure constructed from infinite anionic [(UO2)Cl(H2O)(SO4)]^- layers with [C2H8N]^+ cations balancing the charge and a number of intermoleeular hydrogen bonds (C-H…O and O-H…Cl) existing in the solid state. The fluorescence properties of 1 have also been discussed.展开更多
Two new coordination polymers,{[Co(O2N-Hbtb)(phen)(H2O)3]·2H2O}n 1 and {[Cu3(O2N-btb)2(bipy)2(H2O)4]·4H2O}n 2(O2N-H3btb=5-nitro-1,2,3-benzenetricarboxylic acid,phen=1,10-phenanthroline,bipy=2,2...Two new coordination polymers,{[Co(O2N-Hbtb)(phen)(H2O)3]·2H2O}n 1 and {[Cu3(O2N-btb)2(bipy)2(H2O)4]·4H2O}n 2(O2N-H3btb=5-nitro-1,2,3-benzenetricarboxylic acid,phen=1,10-phenanthroline,bipy=2,2'-bipyridine),were prepared through hydrothermal reactions of Co(Ⅱ) or Cu(Ⅱ) salt with O2N-H3btb in the presence of different auxiliary N-donor ligands.Their crystal structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectroscopy.In the two complexes,O2N-H3btb ligand acts as monodentate and bis-monodentate modes,respectively.Complex 1 displays a two-dimensional layered structure through the inter-and intramolecular hydrogen bonding interactions while complex 2 has an O2N-btb bridged one-dimensional chain which is extended into a three-dimensional network by hydrogen bonding interactions.The magnetic properties of complex 2 are investigated over the temperature range of 2~300 K and ferromagnetic interactions are observed.展开更多
A new nickel(II) complex [NiL2](DMF)4 (HL = 2'-[4-N,N'-(dimethylamino- benzylidene)]-3,5-dihydroxybenzoylhydrazide) has been synthesized and its structure was characterized by IR,UV-Vis,1H NMR and elemental ...A new nickel(II) complex [NiL2](DMF)4 (HL = 2'-[4-N,N'-(dimethylamino- benzylidene)]-3,5-dihydroxybenzoylhydrazide) has been synthesized and its structure was characterized by IR,UV-Vis,1H NMR and elemental analysis. The fluorescence emission mechanism of the complex was discussed by fluorimetric spectra. The single-crystal structure was determined by X-ray diffraction analysis. The crystal belongs to the triclinic system,space group P1 with a = 0.9918(4),b = 1.1297(4),c = 1.1331(4) nm,α = 76.860(7),β = 75.105(6),γ = 89.022(7)°,V = 1.1936(8) nm^3,Z = 1,μ = 0.472 mm^-1,Dc = 1.319 g/cm^3,F(000) = 502 and Rint = 0.0913. In the title compound,the nickel(II) atom is four-coordinated with two nitrogen atoms from amide and two oxygen atoms from keto group. The complex is centrosymmetric with nickel located at the center.展开更多
X-ray powder diffraction, resistivity and magnetization studies have been performed on polycrystalline Nd(FexMn1-x)2Si2 (0≤x 〈 1) compounds which crystallize in a ThCr2Si2-type structure with the space group 14/...X-ray powder diffraction, resistivity and magnetization studies have been performed on polycrystalline Nd(FexMn1-x)2Si2 (0≤x 〈 1) compounds which crystallize in a ThCr2Si2-type structure with the space group 14/mmm. The field-cooled temperature dependence of the magnetization curves shows that, at low temperatures, NdFe2Si2 is antiferromagnetic, while the other compounds show ferromagnetic behaviour. The substitution of Fe for Mn leads to a decrease in lattice parameters a, c and unit-cell volume V. The Curie temperature of the compounds first increases, reaches a maximum around x=0.7, then decreases with Fe content. However, the saturation magnetization decreases monotonically with increasing Fe content. This Fe concentration dependent magnetization of Nd(FexMn1-x)2Si2 compounds can be well explained by taking into account the complex effect on magnetic properties due to the substitution of Mn by Fe. The temperature's square dependence on electrical resistivity indicates that the curve of Nd(Fe0.6Mn0.4)2Si2 has a quasi-linear character above its Curie temperature, which is typical of simple metals.展开更多
A novel organic polycarboxylate N-cyclohexylaziridines-2R,3S-dicarboxylic acid was synthesized and reacted with Ni2(OH)2CO3.As a result,a coordination polymer was obtained.It crystallizes in orthorhombic,space group...A novel organic polycarboxylate N-cyclohexylaziridines-2R,3S-dicarboxylic acid was synthesized and reacted with Ni2(OH)2CO3.As a result,a coordination polymer was obtained.It crystallizes in orthorhombic,space group Pbca with a = 8.6325(10),b = 10.5414(13),c = 27.644(3) ,Z = 4,V = 2515.5(5) 3,C20H34N2Ni2O12,Mr = 611.91,Dc = 1.616 g/cm3,μ = 1.562 mm-1,F(000) = 1280,the final R = 0.0320 and wR = 0.0677 for 2854 independent reflections with Rint = 0.0390.Crystal structure shows that the coordination environment around the Ni(Ⅱ) ion can be described as a slightly distorted octahedron.The ligands act as a bridge through the carboxyl O atoms and join the Ni atoms into an infinite 1D chain structure.The 1D chain forms a 2D network through intermolecular O-H…O hydrogen bonds.The magnetic susceptibility measurements(2~300 K) agree with a weak antiferronmagnetic interaction between neighboring Ni ions in the chain.展开更多
A single crystal of Li3Ba2Ho3(WO4)8 was obtained from a flux of Li2WO4 under an air atmosphere. The structure of the pure crystal was determined by single-crystal X-ray diffraction method. It crystallizes in the mon...A single crystal of Li3Ba2Ho3(WO4)8 was obtained from a flux of Li2WO4 under an air atmosphere. The structure of the pure crystal was determined by single-crystal X-ray diffraction method. It crystallizes in the monoclinic system, space group C2/c with a = 5.240(4), b = 12.790(10), c = 19.247(15), β = 91.921(15)°, V = 1289.1(18)3, Z = 2, Mr = 2773.09, Dc = 7.144 g/cm3, μ = 47.732 mm-1, Rint = 0.0693, F(000) = 2340, the final R = 0.0472 and wR = 0.1221 for 1535 observed reflections (I 2σ(I)). The Li3Ba2Ho3(WO4)8 has a high structure disorder with one 8f site shared by Li(1) and Ho ions with occupancy of 0.25 and 0.75, respectively. The fundamental structure is constituted by distorted square antiprisms Ho/Li(1)O8 with C1 symmetry, distorted Li(2)O6 octahedra and BaO10 polyhedra. The optical properties were investigated by IR and absorption spectroscopy, and the emission cross sections and gain cross sections of 5I7 → 5I8 of Ho3+ were calculated.展开更多
基金supported by the National Natural Science Foundation of China (No. 20772042)
文摘A new complex [Cd(H2biim)2(H2O)2]·(ino)2·4H2O (H2biim = 2,2'-biimidazole, ino = isonicotinate-N-oxide) has been prepared and characterized by single-crystal X-ray diffraction analysis, IR and fluorescence spectra analysis. The crystal is of triclinic system, space group P1 with a = 7.5380(6), b = 8.0402(7), c = 13.5094(11) , α = 104.269(1), β = 93.604(1), γ = 98.349(1)°, V = 780.93(11) 3, Mr = 765.00, Dc = 1.627 g/cm3, F(000) = 390, μ = 0.776 mm-1 and Z = 1. The final R = 0.0322 and wR = 0.0825 for 7038 observed reflections with I 2σ(I) and R = 0.0341 and wR = 0.0832 for all data. The title complex exhibits an infinite chain-like structure through bridging isonicotinate-N-oxide. Strong interchain hydrogen bonds between isonicotinate-N-oxide and H2biim result in the robust 3-D supramolecular architecture. Moreover, the complex shows strong photoluminescence with emission maximum at λ = 401 nm upon λex = 330 nm.
基金Supported by the Foundation of Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces (No. 0506)Department of Education of Zhejiang Province (No. 20071374)
文摘Under hydrothermal condition, the reaction of 2-naphthoxyacetic acid with ZnCl2 and 4,4′-bipyridine (4,4′-bipy) has afforded a new Zn(Ⅱ) compound, [Zn(C12H9O3)2(C10H8N2)]n·nH2O1, which was structurally characterized by single-crystal X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 7.7335(2), b = 19.3834(4), c = 20.1707(4) A, β = 104.9830(10)°, V = 2920.82(11) A^3, C34H28ZnN2O7, Mr = 641.95, Z = 4, Dc = 1.460 g/cm^3,μ = 0.895 mm^-1, F(000) = 1328, R = 0.0406 and wR = 0.0876 for 4417 observed reflections (I〉 2σ(I)) Complex 1 consists of one-dimensional zigzag chains deriving from Zn(C12H9O3)2 units linked by 4,4′-bipy ligands, and lattice water molecules decorate between the chains. Non-covalent interactions, such as hydrogen-bonding and aromatic π-π interactions, lead to the formation of a 3D network structure. The thermogravimetric analysis (TGA) and luminescent property for 1 have also been studied in this paper.
基金Supported by the Fund of Science and Technology Committee of Hunan Province(No.2012GK3030)the Scientific Research Fund of Hunan Provincial Education Department(No.B21018)+2 种基金the Hengyang Bureau of Science & Technology(No.2011kG28)the Science Technology Foundation of Hunan Province(No.2012FJ3020)the Natural Science Foundation of Hunan Province(No.12JJ6013)
文摘One binuclear sodium(Ⅰ) complex [Na2(2-benzoylbenzoato)4(Phen)2(H2O)2]·H2O has been synthesized with 2-benzoylbenzoic acid and 1,10-henanthroline as ligands. The crystal structure was determined by X-ray diffraction. The crystal belongs to the triclinic system with space group P , a = 1.08096(8), b = 1.09619(8), c = 1.09740(8) nm, α = 79.0600(1), β = 71.0450(1), γ = 62.0540(1)o, V = 1.08533(1) nm3, Dc = 1.421 g/cm3, Z = 2, F(000) = 484, GOOF = 1.036, the final R = 0.0363 and wR = 0.0961. The crystal structure shows that two neighboring sodium(Ⅰ) ions are linked together by two bridging water molecules, and each end position is coordinated with one 1,10-phenanthroline molecule and one 2-benzoylbenzoato to form a binuclear structure. Each sodium(Ⅰ) ion in the molecule is coordinated with five atoms to give a distorted trigonal bipyramid. The fluorescence property of the title complex is also discussed.
基金Supported by the Science and Technology Fund of Hengyang Science and Technology Bureau (No. 2008KS035)the Construct Program of the Key Discipline in Hunan Province
文摘A new trinuclear nickel complex,[Ni3(pdc)3(2,2'-bipy)3(H2O)2]·2H2O(H2pdc = pyridine 2,6-dicarboxylic acid,2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized and characterized by IR,elemental analysis and X-ray diffraction methods.Crystal data for this complex:monoclinic,space group P21/n,a = 21.206(4),b = 10.002(2),c = 28.066(6),β = 108.18(3)°,C51H41N9Ni3O16,Mr = 1212.06,V = 5.656(2) nm3,Dc = 1.423 g·cm-3,μ(MoKα) = 1.062 mm-1,Z = 4,F(000) = 2488,GOOF = 1.034,the final R = 0.0543 and wR = 0.1237 for 6149 observed reflections with Ⅰ 〉 2σ(Ⅰ).In the complex,three nickel(Ⅱ) ions are bridged by the pyridine 2,6-dicarboxylic acid groups,and all nickel(Ⅱ) ions are seven-coordinated by nitrogen atoms of 2,2'-bipyridine and pyridine 2,6-dicarboxylic acid and oxygen atoms from pyridine 2,6-dicarboxylic and water to adopt a severely distorted pentagonal bipyramidal geometry.The emission and excitation peaks of the complex in ethanol solutions are located at 336 and 316 nm,respectively.
基金Supported by Higher Education Science Foundation of Jiangsu Province(No.15KJB150031)State Key Laboratory of Structural Chemistry Fund(No.20150009)+1 种基金Yangzhou University for the start-up grantthe Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A new ternary neodymium zirconium sulfide Nd_2ZrS_5 was synthesized by high-temperature solid-state reaction and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Pnma(No. 62) belonging to the Y_2HfS_5 structure-type with a = 11.461(4), b = 8.009(3), c = 7.315(3) A, Z = 2 and V = 671.5(4)A3. Its structure features NdS_8 and ZrS_7 polyhedra-constructed a 3-D network. The data of magnetic susceptibility indicate its antiferromagnetic-like behavior without magnetic order down to 2 K.
基金Supported by the National Natural Science Foundation of China(No.21361011 and 21101081)the Natural Science Foundation of Jiangxi Province(No.20151BAB203002)
文摘The reaction of Cd(NO_3)_2·4H_2O with 4,4?-dipyridylacetylene(4,4?-DPA) and 2-nitroterephthalic acid(2-NO_2-H_2BDC) in DMF/H_2O mixed solvent has afforded a compound {[Cd(2-NO_2-BDC)(4,4?-DPA)]·(DMF)}_n(1). Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the monoclinic system, space group P21/n, with a = 12.1488(3), b = 14.6689(3), c = 13.1615(3) ?, β = 111.809(3)o, V = 2177.63(9) ?~3, Z = 4, C_(23)H_(18)N_4O_7 Cd, M_r = 574.81, D_c = 1.753 g/cm^3, μ = 8.523 mm^(-1), F(000) = 1152, the final R = 0.0411 and wR = 0.1064 for 3589 observed reflections with I 〉 2s(I). In compound 1, the Cd(Ⅱ) ions are linked by the carboxylate groups of 2-NO_2-BDC ligands to give a two-dimensional layered structure based on the centrosymmetric dinuclear Cd_2(COO)_2 units, which are further connected by the 4,4?-DPA ligands to produce a three-dimensional framework with pcu topology. Careful examination revealed that compound 1 is a 2-fold interpenetrating framework. Furthermore, the gas adsorption properties of 1 for N_2 and CO_2 have also been investigated.
基金supported by the National Natural Science Foundation of China(51502221)~~
文摘α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.
基金Project Supported by the Science & Technology Innovation Foundation of Henan Province (No. 092102310309)
文摘Two novel supramolecular complexes,[M4L12]·(HPO4)·(PO4)2(L = 2,2'-dibenzi-midazole,M = Co and Ni) were synthesized by the hydrothermal method and characterized by elemental analysis,IR,UV,and TG-TGA,and the crystal structures were determined by single-crystal X-ray diffraction.The results showed that both of them belong to the cubic system and space group I 4 3d.Crystal parameters of C168H121Co4N48O12P3(1):a = b = c = 2.5104(6) nm,V = 15.820(7) nm3,Mr = 3332.75,Z = 4,Dc = 1.399 Mg/m3,μ = 0.521 mm-1,F(000) = 6852,S = 1.011,the final R = 0.0248 and wR = 0.0663 for 2120 observed reflections(I 2σ(I)) and R = 0.0315 and wR = 0.0706 for all data.Crystal parameters of C168H121Ni4N48O12P3(2):a = b = c = 2.4977(5) nm,V = 15.581(5) nm3,Mr = 3331.87,Z = 4,Dc = 1.420 Mg/m3,μ = 0.587 mm-1,F(000) = 6868,S = 1.074,the final R = 0.0443 and wR = 0.1364 for 1774 observer reflections(I 2σ(I)) and R = 0.0647 and wR = 0.1492 for all data.Each of them consisted of four M(II) cations,twelve 2,2'-dibenzimidazole ligands,one monohydrogen phosphate anion and two phosphate anions in the single cell.The central M(II) cation,coordinated with six alkaline nitrogen atoms from three 2,2'-dibenzimidazole ligands,displayed the expected distorted-octahedral geometry.The 3D supramolecular system was formed by the hydrogen bond N-H...O and π-π stacking interaction between neighboring single cells.Complex 1 showed two irreversible single-electron reduction processes of the central metal ion at-0.06 and-0.42 V in DMF solution.
基金This work was supported by the China Petroleum & Chemical Science and Technology Foundation (No. 205026) the Tianjin Science and Technology Plan Foundation (No. 06TXTJJC14400)
文摘The title compound N,N'-bis(5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl) ethylene diamine (DPTDEDA, C12H26N2O4P2S2) was synthesized by the reaction of neopentyl glycol, phosphorus thio-chloride and 1,2-ethylenediamine, and characterized by elemental analysis, IR and ^1H NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction analysis and the thermal property was analyzed by TG analysis. The crystal structure belongs to monoclinic, space group P21/c, with a = 14.557(16), b = 11.299(12), c = 12.163(13)A,β = 98.707(19)^o, Dc = 1.305 g/cm^3, Z = 4, γ = 0.71073A,μ(MoKa) = 0.447 mm^-1, Mr = 388.41, V = 1977(4)A3, F(000) = 824, S = 1.107, the final R = 0.0478 and wR = 0.0810 for 1738 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that the crystal structure is centrosymmetrically distributed through 1,2-ethylenediamine to join two distorted six-membered rings. The weak N-H…S interactions are observed and link the molecules into sheets. TG analysis shows that the title compound has good thermal stability and char-forming capability, which are required for an excellent intumescent fire retardant.
基金Supported by the Natural Science Foundation of Hunan Province (No. 11JJ9006)Key Project of Science and Technology Plan of Hunan Province (2012FJ2002)+1 种基金Science and Technology Plan of Hunan Province (2012GK3031, 2012WK3029)the Construct Program of Key Discipline in Hunan Province
文摘A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic, space group Co, a = 14.0133(14), b = 16.0409(16), c = 30.372(3) A, β = 100.8950(10)°, V = 6704.1(12) A3, Dc = 1.364 g/cm3, Z = 8,μ(MoKa) = 0.704 mml, F(000) = 2840, the final R= 0.0552 and wR = 0.1431. In the crystal structure, the whole molecule consists of two copper ions, four 2-benzoylbenzoic acid molecules, two 2,2′-bipyridine molecules and two water molecules. Each central copper ion is coordinated with two nitrogen atoms from one 2,2′-bipyridine molecule and three oxygen atoms from two 2-benzoylbenzoic acids and one water molecule, respectively, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.
基金Supported by the National Natural Science Foundation of China (20761002)the Natural Science Foundation of Guangxi Province (0832080)the Innovation Project of Guangxi Graduate Education (2008106080817M366)
文摘A novel compound 4,8,10-trimethyl-2-(3,5-dimethylpyrazol)-pyrido-[2',3':3,4]-py-razol-[1,5-5-a]-pyrimidine(C17H18N6) has been synthesized from 2,6-dichloro-4-methylnico-tino-nitrile,hydrazine and acetylacetone by substitution and cyclolization.The structure was charac-terized by elemental analysis,1H NMR and IR,and single-crystal structure was determined by X-ray diffraction analysis.The compound crystallizes in the monoclinic system,space group P21/c with a = 8.0338(9),b = 28.618(3),c = 7.2688(8),β = 111.051(2)o,V = 1559.6(3) 3,Z = 4,Dc = 1.305 g/cm3,μ = 0.083 mm-1,Mr = 306.37,F(000) = 648,S = 0.971,the final R = 0.0795 and wR = 0.1746 for 1457 observed reflections(Ⅰ 〉 2σ(Ⅰ)).The results demonstrate that the pyridine,pyrazole and pyrimidine rings are nearly coplanar,which is evident from the dihedral angles among the four rings in the range of 0.13~4.15o.The face-to-face π-π stacking interactions among pyridine,pyrazol and pyrimidine rings result in a supramolecular crystal,in which they seem to be effective in stabilizing the structure.Meanwhile,the fluorescence properties of the title compound were discussed,which showed very strong fluorescence.The calculated results(selected bond lengths,bond angles and torsion angles) are all typical and agree well with the experimental results,which demonstrates that B3LYP/6-31+G* is suitable for the title compound.
基金supported by the National Natural Science Foundation of China(No.21573189)the Undergraduate Training Programs of Innovation and Entrepreneurship of Shaanxi Province(No.1537)
文摘Two alkaline earth metal coordination polymers [M(2-Hstp)(H2O)] (M = Ca2+ (1) and Sr2+ (2), 2-H3stp = 2-sulfoterephthalate) were synthesized under hydrothermal conditions by the precursor [Mn(2-Hstp)2(4,4?-Hbpy)2] and alkaline earth metal salts. The two alkaline earth complexes are not isomorphic. Complex 1 crystallizes in the monoclinic space group P21/m, while 2 in the monoclinic space group P21/c, despite of their similar formulas. In 1, the Ca2+ ion lies in a seven-coordinated pentagon bipyramidal configuration, coordinated with five 2-Hstp2- anions and one water molecule. However, the Sr2+ ion in 2 is coordinated by nine oxygen atoms to form a single-capped square antiprism polyhedron. Both 1 and 2 exhibit π-π* emission of the 2-sulfotere- phthalate ligand.
基金supported by the National Natural Science Foundation of China(No.21271035)the Natural Science Foundation of Anhui Province(No.KJ2016A512)+1 种基金Key projects of Anhui Province University Outstanding Youth Talent Support Program(No.gxyqZD2016372)the Natural Science Foundation of Chizhou University(No.2017ZRZ002)
文摘A new naphthol-based compound 1, C22 H22 N2 O2, has been designed and synthesized. The structure of the title compound 1 was confirmed by IR, 1 H NMR, 13 C NMR, H RMS, and X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/c, with a = 12.888(9), b = 15.543(10), c = 9.119(6) ?, β = 94.05(3)°, V = 1822(2) ?3, Z = 4, Dc = 1.263 g/cm3, Mr = 346.41, μ = 0.081 mm-1, F(000) = 736.0, the final R = 0.0452 and wR = 0.1142 for 3404 observed reflections with(I 〉 2σ(I)). The crystal structure of 1 is stabilized by O–H···N, N–H···O, C–H···O hydrogen bonds and π-π interactions. The spectroscopic studies of 1 toward various metal ions were also investigated in 25%(V/V) ethanol aqueous solution, and the result showed that it can selectively recognize Zn2+ with fluorescence enhancement.
基金financially supported by the National Natural Science Foundation of China(21603069)College Students’ Science and Technology Innovation Project of Hubei Polytechnic University(No.14cx16)Young College Teachers’ Entering into Enterprises Program of Hubei Provincial Department of Education(No.XD2014677)
文摘A benzothiazole-based compound 1, C28H24N4O2S, has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 9.6309(14), b = 15.230(2), c = 17.197(3)A, β = 105.222(2)°, V = 2433.9(6) A^3, Z = 4, F(000) = 1008, Dc = 1.311 Mg/m^3, Mr = 480.57, μ = 0.166 mm^-1, the final R = 0.0509 and wR = 0.1481 for 6643 observed reflections with I 〉 2σ(I). The crystal structure of compound 1 is stabilized by C–H…O, N–H…N, N–H…O, O–H…N and C–H…N hydrogen bonds. The spectroscopic studies of the title compound toward various metal ions were also investigated in 25%(V/V) ethanol aqueous solution, and the result showed that it can selectively recognize Cu^2+ with fluorescence quenching.
基金Supported by the Project of Natural Science Foundations of Fujian (No. 2008J0172)National Natural Science Foundation of China (20705031)
文摘An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and spectral techniques. 1 belongs to monoclinic, space group P21/c with a = 8.3545(17), b = 10.550(2), c = 12.370(3)A, β = 102.64(3)°, V = 1063.9(4)A3, Mr = 464.64, De= 2.901 g/cm^3, F(000) = 836,μ = 15.710 mm^-1, Z= 4, the final R = 0.0286 and wR = 0.0685 for 10164 observed reflections with Ⅰ 〉 2σ(Ⅰ). 1 presents a two-dimensional layer-like structure constructed from infinite anionic [(UO2)Cl(H2O)(SO4)]^- layers with [C2H8N]^+ cations balancing the charge and a number of intermoleeular hydrogen bonds (C-H…O and O-H…Cl) existing in the solid state. The fluorescence properties of 1 have also been discussed.
基金Supported by the National Natural Science Foundation of China (Nos. 20471026 and 20771054)the Henan Tackle Key Problem of Science and Technology (Nos. 072102270030 and 072102270034)2009GGJS-104
文摘Two new coordination polymers,{[Co(O2N-Hbtb)(phen)(H2O)3]·2H2O}n 1 and {[Cu3(O2N-btb)2(bipy)2(H2O)4]·4H2O}n 2(O2N-H3btb=5-nitro-1,2,3-benzenetricarboxylic acid,phen=1,10-phenanthroline,bipy=2,2'-bipyridine),were prepared through hydrothermal reactions of Co(Ⅱ) or Cu(Ⅱ) salt with O2N-H3btb in the presence of different auxiliary N-donor ligands.Their crystal structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectroscopy.In the two complexes,O2N-H3btb ligand acts as monodentate and bis-monodentate modes,respectively.Complex 1 displays a two-dimensional layered structure through the inter-and intramolecular hydrogen bonding interactions while complex 2 has an O2N-btb bridged one-dimensional chain which is extended into a three-dimensional network by hydrogen bonding interactions.The magnetic properties of complex 2 are investigated over the temperature range of 2~300 K and ferromagnetic interactions are observed.
基金Project supported by the Natural Science Foundation of Zhejiang Province (Y406049)Education Committee Foundation of Zhejiang Province (No. 20060079)
文摘A new nickel(II) complex [NiL2](DMF)4 (HL = 2'-[4-N,N'-(dimethylamino- benzylidene)]-3,5-dihydroxybenzoylhydrazide) has been synthesized and its structure was characterized by IR,UV-Vis,1H NMR and elemental analysis. The fluorescence emission mechanism of the complex was discussed by fluorimetric spectra. The single-crystal structure was determined by X-ray diffraction analysis. The crystal belongs to the triclinic system,space group P1 with a = 0.9918(4),b = 1.1297(4),c = 1.1331(4) nm,α = 76.860(7),β = 75.105(6),γ = 89.022(7)°,V = 1.1936(8) nm^3,Z = 1,μ = 0.472 mm^-1,Dc = 1.319 g/cm^3,F(000) = 502 and Rint = 0.0913. In the title compound,the nickel(II) atom is four-coordinated with two nitrogen atoms from amide and two oxygen atoms from keto group. The complex is centrosymmetric with nickel located at the center.
基金Project supported by the National Basic Research Program of China (Grant No 2006CB601101)
文摘X-ray powder diffraction, resistivity and magnetization studies have been performed on polycrystalline Nd(FexMn1-x)2Si2 (0≤x 〈 1) compounds which crystallize in a ThCr2Si2-type structure with the space group 14/mmm. The field-cooled temperature dependence of the magnetization curves shows that, at low temperatures, NdFe2Si2 is antiferromagnetic, while the other compounds show ferromagnetic behaviour. The substitution of Fe for Mn leads to a decrease in lattice parameters a, c and unit-cell volume V. The Curie temperature of the compounds first increases, reaches a maximum around x=0.7, then decreases with Fe content. However, the saturation magnetization decreases monotonically with increasing Fe content. This Fe concentration dependent magnetization of Nd(FexMn1-x)2Si2 compounds can be well explained by taking into account the complex effect on magnetic properties due to the substitution of Mn by Fe. The temperature's square dependence on electrical resistivity indicates that the curve of Nd(Fe0.6Mn0.4)2Si2 has a quasi-linear character above its Curie temperature, which is typical of simple metals.
文摘A novel organic polycarboxylate N-cyclohexylaziridines-2R,3S-dicarboxylic acid was synthesized and reacted with Ni2(OH)2CO3.As a result,a coordination polymer was obtained.It crystallizes in orthorhombic,space group Pbca with a = 8.6325(10),b = 10.5414(13),c = 27.644(3) ,Z = 4,V = 2515.5(5) 3,C20H34N2Ni2O12,Mr = 611.91,Dc = 1.616 g/cm3,μ = 1.562 mm-1,F(000) = 1280,the final R = 0.0320 and wR = 0.0677 for 2854 independent reflections with Rint = 0.0390.Crystal structure shows that the coordination environment around the Ni(Ⅱ) ion can be described as a slightly distorted octahedron.The ligands act as a bridge through the carboxyl O atoms and join the Ni atoms into an infinite 1D chain structure.The 1D chain forms a 2D network through intermolecular O-H…O hydrogen bonds.The magnetic susceptibility measurements(2~300 K) agree with a weak antiferronmagnetic interaction between neighboring Ni ions in the chain.
基金supported by the National Natural Science Foundation of China(20971123,51002153,21007070,51102232,61106004 and 21103191)
文摘A single crystal of Li3Ba2Ho3(WO4)8 was obtained from a flux of Li2WO4 under an air atmosphere. The structure of the pure crystal was determined by single-crystal X-ray diffraction method. It crystallizes in the monoclinic system, space group C2/c with a = 5.240(4), b = 12.790(10), c = 19.247(15), β = 91.921(15)°, V = 1289.1(18)3, Z = 2, Mr = 2773.09, Dc = 7.144 g/cm3, μ = 47.732 mm-1, Rint = 0.0693, F(000) = 2340, the final R = 0.0472 and wR = 0.1221 for 1535 observed reflections (I 2σ(I)). The Li3Ba2Ho3(WO4)8 has a high structure disorder with one 8f site shared by Li(1) and Ho ions with occupancy of 0.25 and 0.75, respectively. The fundamental structure is constituted by distorted square antiprisms Ho/Li(1)O8 with C1 symmetry, distorted Li(2)O6 octahedra and BaO10 polyhedra. The optical properties were investigated by IR and absorption spectroscopy, and the emission cross sections and gain cross sections of 5I7 → 5I8 of Ho3+ were calculated.