The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu(Ⅱ) in the proportion of 3:2:2 yields a new tetranuclear copper(Ⅱ) complex, [Cu2L]2(ClO4)2.2H2O(H3L= N,N'-bis(4-(3'-formyl-5'-methylsa...The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu(Ⅱ) in the proportion of 3:2:2 yields a new tetranuclear copper(Ⅱ) complex, [Cu2L]2(ClO4)2.2H2O(H3L= N,N'-bis(4-(3'-formyl-5'-methylsalicyclidene)iminoethyl)-4-methyl-2,6-bimethyliminophenol). The complex has been characterized by ES-MS, IR and X-ray diffraction analysis, and its crystal crystallizes in the triclinic system, space group P1 with a = 10.8673(11), b = 12.0829(12), c = 14.4834(15) А, α= 111.946(2), β= 105.828(2), γ = 99.583(2)°,V= 1618.5(3) А^3, Dc = 1.605 g/cm^3, Z = 2, Mr = 1564.26, F(000) = 800.0,μ(MoKa) = 1.460/mm, S = 1.063, R = 0.0612 and wR = 0.1163 for 6245 observed reflections (I 〉 2σ(I)). The complex is a dimer of dinuclear copper(Ⅱ) acylic enantiomorph subunit [Cu2L]ClO4.H_2O, held together by π…π weak coordination and hydrogen bonding interactions. In addition, the π…π interactions related to phenyl moieties as well as CH=N…π interactions were also found to stabilize the supramolecular architectures in the solid state.展开更多
The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1....The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β= 93.998(11)° , γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R 1= 0.065 4 , wR 2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er 3+ ions connected by four μ 3OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ 3OH, three carboxylic oxygen atoms from three αalanine and two oxygen atoms from water molecules, forming a squareantiprismatic coordination polyhedron.展开更多
The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1....The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β= 93.998(11)° , γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R 1= 0.065 4 , wR 2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er 3+ ions connected by four μ 3OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ 3OH, three carboxylic oxygen atoms from three αalanine and two oxygen atoms from water molecules, forming a squareantiprismatic coordination polyhedron.展开更多
The title tetranuclear complex,(μ4-oxo)-hexakis(μ2-chloro)-tetrakis(2-amino-1,3-thiazole-N)-tetra-copper(ii) [Cu4(μ4-O)(μ-Cl)6L4](1,L=2-amino-1,3-thiazole) was synthesized by the reaction of CuCl2...The title tetranuclear complex,(μ4-oxo)-hexakis(μ2-chloro)-tetrakis(2-amino-1,3-thiazole-N)-tetra-copper(ii) [Cu4(μ4-O)(μ-Cl)6L4](1,L=2-amino-1,3-thiazole) was synthesized by the reaction of CuCl2·2H2O with 2-amino-1,3-thiazole in methanol and characterized by IR spectra and X-ray diffraction.Complex 1 crystallizes in triclinic,space group P1 with a=9.7137(2),b=10.7005(2),c=14.6505(2),α=83.9550(10),β=82.0930(10),γ=67.1640(10)°,V=1387.84(4)3,Mr=883.43,Z=2,μ=3.927 mm-1,Dc=2.1144 g/cm3,F(000)=868,R=0.0332 and wR=0.0814.The complex contains a tetrahedron of four CuII atoms coordinating to a central μ4-O atom,with the six edges of the tetrahedron bridged by six Cl atoms.The Cu-O bond distances range from 1.910(2) to 1.918(2),Cu-Cl from 2.3501(11) to 2.5924(10),and Cu-Cu from 3.1003(6) to 3.1663(6).The coordination geometries of the four coppers distort from trigonal bipramid to tetragonal pyramid with different distortion factors.The free animo groups of the ligands result in a lot of N-H···Cl and N-H···N intra-and intermolecular hydrogen bonds.展开更多
The self-assembly of clusters in inorganic systems is an interesting subject. The self-assembly of big molecules has been well established in biological systems. In addition, the coordination chemistry of metal-sulfur...The self-assembly of clusters in inorganic systems is an interesting subject. The self-assembly of big molecules has been well established in biological systems. In addition, the coordination chemistry of metal-sulfur-nitrogen cluster complexes has been a very active and attracting field for many years as a result of the novelty and versatility of the crystal structures and reactivities of such clusters, as well as their potential applications as the models for the active sites in non-heme proteins. At the same time, there is currently considerable interest in the formation of metal complexes with heterocyclic ligands because of the diverse characteristics of ligands and their consequential wide range of applications.展开更多
A new tetranuclear zinc(II) complex [Zn4(SO4)2(DPPZ)4(HSal)2(OH)2] 1 (DPPZ = dipyrido[3,2-a:2',3'-c]phenazine, H2Sal = salicylic acid) was prepared by using hydrothermal synthesis and characterized by e...A new tetranuclear zinc(II) complex [Zn4(SO4)2(DPPZ)4(HSal)2(OH)2] 1 (DPPZ = dipyrido[3,2-a:2',3'-c]phenazine, H2Sal = salicylic acid) was prepared by using hydrothermal synthesis and characterized by elemental analysis, IR spectrum, thermal gravimetry (TG), fluorescent emission and single-crystal X-ray diffraction. Its crystal structure is of monoclinic, space group P2 1/c with a = 9.8897(8), b = 14.2506(12), c = 26.384(2) ,A, β = 94.8940(10)°, V = 3704.8(5) A3 Z = 2, C86H52N16O16S2Zn4, Mr = 1891.04, Dc = 1.695 g/cm^3, μ= 1.423 mm^-1, F(000) = 1920, GOOF = 1.039, the final R = 0.0358 and wR = 0.0872 for 6038 observed reflections with I 〉 2σ(I). In 1, "cage-like" tetranuclear clusters of [Zn4(SO4)2(DPPZ)4(HSal)2(OH)2] are further stacked through π-π interactions to generate a 3D supramolecular network.展开更多
The nonrelativistic DV-X_α-SCC method was used to study the electronic structure and chemi- cal bonding of tetranuclear neodymium complex Nd_4O(OR)_4(NR′_2)_6,with emphasis on the bonding charac- ter of the central ...The nonrelativistic DV-X_α-SCC method was used to study the electronic structure and chemi- cal bonding of tetranuclear neodymium complex Nd_4O(OR)_4(NR′_2)_6,with emphasis on the bonding charac- ter of the central μ_4-O atom and the four Nd atoms.The results of calculation show that the μ_4-O atom uses its sp^3 valence orbitals to contribute four O-Nd bonding MOs with character of multicenter bond apparent- ly.The Mulliken population analysis shows that the overlap population between Nd atoms is almost equal to zero,therefore there is no direct metal-metal bond between Nd atoms.The coordination number of Nd in the complex is discussed briefly.展开更多
The preparation and characterization of [CrnFe4-nO2(O2CMe)7(bipy)2]Cl (1, n=0; 2, n=2; 3, n=4, bipy=2,2'-bipyridine) are described. The three complexes (1, 2 and 3) are obtained by tipyridine-mediated conversion o...The preparation and characterization of [CrnFe4-nO2(O2CMe)7(bipy)2]Cl (1, n=0; 2, n=2; 3, n=4, bipy=2,2'-bipyridine) are described. The three complexes (1, 2 and 3) are obtained by tipyridine-mediated conversion of trinuclear [CrnFe3-nO(O2CMe)6(H2O)3]+(1, n=0; 2, n=1;3, n=3), and crystallized as three of approximate isomorphs. Crystal 2 is monoclinic with space group C2/c, a=27.454(5)A, b=11.789(1)A, c=16.570(3)A, B=118.78(1), V=4700.8A, z=4, u(MoKa)=11.64cm-1, F(000)=2056, final R=0.058 and Rw=0.066 for 3479 reflections with I > 3o(I). The Fe and Cr atoms in the cation are all +3 oxide state and disordered in the lattice, which is also supported by its Mossbauer studies. The [Cr2Fe2O2]8+ core can be thought of as being derived from two edge-sharing M3O units (M=Fe or Cr), and as a butterfly-like structure. The cations' structure of all three crystals are similar to each other and have C2 symmetry. The species are characterized by IR spectra and magnetic techniques, with particular emphasis on differentiation of coordination bond strengths and electronic environment of metal atoms in these complexes.展开更多
A new tetranuclear silver(I) complex with the formula of [Ag4(MMPzA)2(dmPz)4(H2DPC)2](H2O)4(1, MMPz A = mono(3,5-bimethyl-pyrazolmethyl)amine), dm Pz = 3,5-dimethylpyrazole, H2DPC = pyridine-3,4-dicarbox...A new tetranuclear silver(I) complex with the formula of [Ag4(MMPzA)2(dmPz)4(H2DPC)2](H2O)4(1, MMPz A = mono(3,5-bimethyl-pyrazolmethyl)amine), dm Pz = 3,5-dimethylpyrazole, H2DPC = pyridine-3,4-dicarboxylic acid) has been synthesized and characterized by single-crystal X-ray diffraction method. The title complex crystallizes in the triclinic system, space group P1 with a = 10.5532(13), b = 11.5071(18), c = 13.3951(17) A, α = 97.3190(10), β = 106.7360(10), γ = 108.0770(10)o, V = 1438.3(3) A3, Z = 1, Dc = 1.691 g/cm3, F(000) = 736, μ = 1.421 mm-1, the final R = 0.0400 and w R = 0.0942 for 5097 observed reflections(I 〉 2σ(I)). The intermolecular hydrogen bonding interaction extends the complex into a 1D chain structure. In addition, the complex was tested in vitro for its antibacterial activity and it exhibited significant activity, especially against penicillium.展开更多
In this work, novel oxidative coupling complexes, [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] (n = 1 or 2, X = Cl or Br, Pip ...In this work, novel oxidative coupling complexes, [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] (n = 1 or 2, X = Cl or Br, Pip = piperidine), are synthesized from the reaction of well characterized Lewis base [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>O<sub>2</sub>] with carbon dioxide as a Lewis acid in CH<sub>2</sub>Cl<sub>2</sub>. These carbonato-derivatives are isolated as stable solids. They are easily soluble in aprotic solvents as CH<sub>2</sub>Cl<sub>2</sub>or phNO<sub>2</sub>. Cryoscopic measurements support tetranuclear structure for all of them. Electronic spectra in the near infrared with high molecular absorptivity may be explained for tetranuclear cuban structure to fulfil 3 halo-ligands for each copper centre in [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>]. The EPR spectra for [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] complexes are axial type of spectra (d<sub>x2-y2</sub> G.S) suggesting elongated tetragonal distortion for all of them. Cyclic voltammograms for [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] are irreversible in character. These tetranuclear carbonato complexes show catalytical activity. They initiate the oxidation of 2,6-dimethylphenol (DMP) to 3,3’,5,5’-tetramethyl-4,4’-diphenoquinone (DPQ).展开更多
A tetranuclear Ln(Ⅲ)-based complex:[Dy_(4)(dbm)_(4)(L)_(6)(μ_(3)-OH)_(2)]·CH_(3)CN(1)(HL=5-[(4-methylbenzylidene)amino]quinolin-8-ol,Hdbm=dibenzoylmethane)was manufactured and its structure was characterized in...A tetranuclear Ln(Ⅲ)-based complex:[Dy_(4)(dbm)_(4)(L)_(6)(μ_(3)-OH)_(2)]·CH_(3)CN(1)(HL=5-[(4-methylbenzylidene)amino]quinolin-8-ol,Hdbm=dibenzoylmethane)was manufactured and its structure was characterized in detail.Xray diffraction analysis shows that complex 1 belongs to the monoclinic crystal system and its space group is P2_1/n,which contains a rhombic Dy_(4)core.Magnetic measurements of 1 suggest it possesses extraordinary single-molecule magnet(SMM)behavior.Its energy barrier U_(eff)/k_(B)was 116.7 K,and the pre-exponential coefficient τ_(0)=1.05×10~(-8)s.CCDC:2359322.展开更多
One novel Co(II) coordination polymer, namely [Co4(L)6(NO3)2] (1) was prepared by solvothermal reactions of Co(NO3)2 with a (E)-2-[2-(3-thienyl)ethenyl]-8-quinolinol ligand (HL), which has been determi...One novel Co(II) coordination polymer, namely [Co4(L)6(NO3)2] (1) was prepared by solvothermal reactions of Co(NO3)2 with a (E)-2-[2-(3-thienyl)ethenyl]-8-quinolinol ligand (HL), which has been determined by single-crystal X-ray diffraction analyses and further characterized by means of elemental analyses, IR spectra, PXRD and thermogravimetric analyses (TGA). The core structure of complex 1 is an incomplete dicubane-like tetranuclear Co(II) cluster, which is surrounded by six 8-hydroxy-quinolinate-based ligands and two nitrate ligands. Weak S-O interactions between the thienyl groups and nitrate ligands extend the adjacent tetranuclear CoOI) clusters into a supramolecular (4, 4) net structure. Magnetic measurement indicates that the coupling within both molecules is overall antiferromagnetic.展开更多
A metal-organic coordination polymer [ZnE.s(phen)(BDC)2(OH)]2 (phen = 1,10- phenanthroline, BDC = benzene-1,4-dicarboxylic acid) 1 has been hydrothermally synthesized and structurally characterized by single-c...A metal-organic coordination polymer [ZnE.s(phen)(BDC)2(OH)]2 (phen = 1,10- phenanthroline, BDC = benzene-1,4-dicarboxylic acid) 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The complex crystallizes in the triclinic system, space group PI with a = 11.199(2), b = 11.593(2), c = 11.865(3)/A, α= 99.330(1), β = 111.506(1), γ = 104.804(1)^o, V= 1328.4(5)A^3, Dc= 1.722 g/cm^3, Z = 1, Mr = 1377.82, F(000) = 692,μ(MoKa) = 2.306 mm^-1, S = 1.093, R= 0.0281 and wR = 0.0756 for 4179 observed reflections (I 〉 2σ(/)). The coordination polyhedron around Zn(II) can be described as a tetrahedron, trigonal bipyramid and octahedron. It is worth noting that the crystal structure of 1 is composed of tetranuclear zinc clusters linked by {ZnO6} units.展开更多
An O-Vanillin-methionine Schiff Base complex with copper(Ⅱ) has been synthesized under a mild condition. The complex has been characterized by elemental analysis, UV, FT-IR, TG-DTA and XRD. The crystal structure of t...An O-Vanillin-methionine Schiff Base complex with copper(Ⅱ) has been synthesized under a mild condition. The complex has been characterized by elemental analysis, UV, FT-IR, TG-DTA and XRD. The crystal structure of the complex belongs to monoclinic, with space group C2/C, a=2.070 4(12) nm, b=1.431 9(8) nm, c=2.812 9(11) nm, β=133.15(2)°, V=6.084(5) nm 3, Z=8, D c= 0.998 Mg/m 3, F(000)=1 836, final R=0.121 8. The results revealed it is a tetranuclear copper(Ⅱ) complex.展开更多
A tetranuclear Mn(Ⅳ) complex \{\[L\-4Mn\-4O\-6\]\}(ClO\-4)\-4\52H\-2O (L=tacn)was synthesized from Mn(CH\-3COO)\-2\54H\-2O, tacn and NaClO\-4 and characterized by XRD. The compound crystallizes in monoclinic system, ...A tetranuclear Mn(Ⅳ) complex \{\[L\-4Mn\-4O\-6\]\}(ClO\-4)\-4\52H\-2O (L=tacn)was synthesized from Mn(CH\-3COO)\-2\54H\-2O, tacn and NaClO\-4 and characterized by XRD. The compound crystallizes in monoclinic system, space group P2\-1/n , with a =2.133 5(6) nm, b =1.138 7(3) nm, \{ c =\}\{2.178 8(6) nm\}, β =67.40(3)°, V =4.928(2) nm 3 , Z =4, R =0.062 0. Magnetic investigations reveal a weak ferromagnetic property with J =8.8 cm -1 .展开更多
基金Supported by the key Foundation of the Education Department of Hubei Province (No. D20081503)the foundation of the innovative group of the Education Department of Hubei Province (T200802)
文摘The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu(Ⅱ) in the proportion of 3:2:2 yields a new tetranuclear copper(Ⅱ) complex, [Cu2L]2(ClO4)2.2H2O(H3L= N,N'-bis(4-(3'-formyl-5'-methylsalicyclidene)iminoethyl)-4-methyl-2,6-bimethyliminophenol). The complex has been characterized by ES-MS, IR and X-ray diffraction analysis, and its crystal crystallizes in the triclinic system, space group P1 with a = 10.8673(11), b = 12.0829(12), c = 14.4834(15) А, α= 111.946(2), β= 105.828(2), γ = 99.583(2)°,V= 1618.5(3) А^3, Dc = 1.605 g/cm^3, Z = 2, Mr = 1564.26, F(000) = 800.0,μ(MoKa) = 1.460/mm, S = 1.063, R = 0.0612 and wR = 0.1163 for 6245 observed reflections (I 〉 2σ(I)). The complex is a dimer of dinuclear copper(Ⅱ) acylic enantiomorph subunit [Cu2L]ClO4.H_2O, held together by π…π weak coordination and hydrogen bonding interactions. In addition, the π…π interactions related to phenyl moieties as well as CH=N…π interactions were also found to stabilize the supramolecular architectures in the solid state.
基金Supported by the National Key Project of Fundamental Research and the National Natural Science Foundation ofChina(No.29771001,
文摘The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β= 93.998(11)° , γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R 1= 0.065 4 , wR 2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er 3+ ions connected by four μ 3OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ 3OH, three carboxylic oxygen atoms from three αalanine and two oxygen atoms from water molecules, forming a squareantiprismatic coordination polyhedron.
基金Supported by the National Key Project of Fundamental Research and the National Natural Science Foundation ofChina(No.29771001,
文摘The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β= 93.998(11)° , γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R 1= 0.065 4 , wR 2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er 3+ ions connected by four μ 3OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ 3OH, three carboxylic oxygen atoms from three αalanine and two oxygen atoms from water molecules, forming a squareantiprismatic coordination polyhedron.
基金supported by the Scientific Research Common Program of Beijing Municipal Commission of Education (No. KM201010028008)
文摘The title tetranuclear complex,(μ4-oxo)-hexakis(μ2-chloro)-tetrakis(2-amino-1,3-thiazole-N)-tetra-copper(ii) [Cu4(μ4-O)(μ-Cl)6L4](1,L=2-amino-1,3-thiazole) was synthesized by the reaction of CuCl2·2H2O with 2-amino-1,3-thiazole in methanol and characterized by IR spectra and X-ray diffraction.Complex 1 crystallizes in triclinic,space group P1 with a=9.7137(2),b=10.7005(2),c=14.6505(2),α=83.9550(10),β=82.0930(10),γ=67.1640(10)°,V=1387.84(4)3,Mr=883.43,Z=2,μ=3.927 mm-1,Dc=2.1144 g/cm3,F(000)=868,R=0.0332 and wR=0.0814.The complex contains a tetrahedron of four CuII atoms coordinating to a central μ4-O atom,with the six edges of the tetrahedron bridged by six Cl atoms.The Cu-O bond distances range from 1.910(2) to 1.918(2),Cu-Cl from 2.3501(11) to 2.5924(10),and Cu-Cu from 3.1003(6) to 3.1663(6).The coordination geometries of the four coppers distort from trigonal bipramid to tetragonal pyramid with different distortion factors.The free animo groups of the ligands result in a lot of N-H···Cl and N-H···N intra-and intermolecular hydrogen bonds.
基金Supported by the National Natural Science Foundation of China(Nos. 20476011 and 20371007).
文摘The self-assembly of clusters in inorganic systems is an interesting subject. The self-assembly of big molecules has been well established in biological systems. In addition, the coordination chemistry of metal-sulfur-nitrogen cluster complexes has been a very active and attracting field for many years as a result of the novelty and versatility of the crystal structures and reactivities of such clusters, as well as their potential applications as the models for the active sites in non-heme proteins. At the same time, there is currently considerable interest in the formation of metal complexes with heterocyclic ligands because of the diverse characteristics of ligands and their consequential wide range of applications.
基金Supported by the Natural Science Foundation of Jilin Province (No. 20060516)the Doctoral Foundation of Jilin Normal University (No. 2006006 and No. 2007009)+1 种基金the Science and Technology Institute Foundation of Siping City (No. 2005016)the Subject and Base Construction Foundation of Jilin Normal University (No. 2006041)
文摘A new tetranuclear zinc(II) complex [Zn4(SO4)2(DPPZ)4(HSal)2(OH)2] 1 (DPPZ = dipyrido[3,2-a:2',3'-c]phenazine, H2Sal = salicylic acid) was prepared by using hydrothermal synthesis and characterized by elemental analysis, IR spectrum, thermal gravimetry (TG), fluorescent emission and single-crystal X-ray diffraction. Its crystal structure is of monoclinic, space group P2 1/c with a = 9.8897(8), b = 14.2506(12), c = 26.384(2) ,A, β = 94.8940(10)°, V = 3704.8(5) A3 Z = 2, C86H52N16O16S2Zn4, Mr = 1891.04, Dc = 1.695 g/cm^3, μ= 1.423 mm^-1, F(000) = 1920, GOOF = 1.039, the final R = 0.0358 and wR = 0.0872 for 6038 observed reflections with I 〉 2σ(I). In 1, "cage-like" tetranuclear clusters of [Zn4(SO4)2(DPPZ)4(HSal)2(OH)2] are further stacked through π-π interactions to generate a 3D supramolecular network.
基金The project supported by the National Natural Science Foundation of China
文摘The nonrelativistic DV-X_α-SCC method was used to study the electronic structure and chemi- cal bonding of tetranuclear neodymium complex Nd_4O(OR)_4(NR′_2)_6,with emphasis on the bonding charac- ter of the central μ_4-O atom and the four Nd atoms.The results of calculation show that the μ_4-O atom uses its sp^3 valence orbitals to contribute four O-Nd bonding MOs with character of multicenter bond apparent- ly.The Mulliken population analysis shows that the overlap population between Nd atoms is almost equal to zero,therefore there is no direct metal-metal bond between Nd atoms.The coordination number of Nd in the complex is discussed briefly.
文摘The preparation and characterization of [CrnFe4-nO2(O2CMe)7(bipy)2]Cl (1, n=0; 2, n=2; 3, n=4, bipy=2,2'-bipyridine) are described. The three complexes (1, 2 and 3) are obtained by tipyridine-mediated conversion of trinuclear [CrnFe3-nO(O2CMe)6(H2O)3]+(1, n=0; 2, n=1;3, n=3), and crystallized as three of approximate isomorphs. Crystal 2 is monoclinic with space group C2/c, a=27.454(5)A, b=11.789(1)A, c=16.570(3)A, B=118.78(1), V=4700.8A, z=4, u(MoKa)=11.64cm-1, F(000)=2056, final R=0.058 and Rw=0.066 for 3479 reflections with I > 3o(I). The Fe and Cr atoms in the cation are all +3 oxide state and disordered in the lattice, which is also supported by its Mossbauer studies. The [Cr2Fe2O2]8+ core can be thought of as being derived from two edge-sharing M3O units (M=Fe or Cr), and as a butterfly-like structure. The cations' structure of all three crystals are similar to each other and have C2 symmetry. The species are characterized by IR spectra and magnetic techniques, with particular emphasis on differentiation of coordination bond strengths and electronic environment of metal atoms in these complexes.
文摘A new tetranuclear silver(I) complex with the formula of [Ag4(MMPzA)2(dmPz)4(H2DPC)2](H2O)4(1, MMPz A = mono(3,5-bimethyl-pyrazolmethyl)amine), dm Pz = 3,5-dimethylpyrazole, H2DPC = pyridine-3,4-dicarboxylic acid) has been synthesized and characterized by single-crystal X-ray diffraction method. The title complex crystallizes in the triclinic system, space group P1 with a = 10.5532(13), b = 11.5071(18), c = 13.3951(17) A, α = 97.3190(10), β = 106.7360(10), γ = 108.0770(10)o, V = 1438.3(3) A3, Z = 1, Dc = 1.691 g/cm3, F(000) = 736, μ = 1.421 mm-1, the final R = 0.0400 and w R = 0.0942 for 5097 observed reflections(I 〉 2σ(I)). The intermolecular hydrogen bonding interaction extends the complex into a 1D chain structure. In addition, the complex was tested in vitro for its antibacterial activity and it exhibited significant activity, especially against penicillium.
文摘In this work, novel oxidative coupling complexes, [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] (n = 1 or 2, X = Cl or Br, Pip = piperidine), are synthesized from the reaction of well characterized Lewis base [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>O<sub>2</sub>] with carbon dioxide as a Lewis acid in CH<sub>2</sub>Cl<sub>2</sub>. These carbonato-derivatives are isolated as stable solids. They are easily soluble in aprotic solvents as CH<sub>2</sub>Cl<sub>2</sub>or phNO<sub>2</sub>. Cryoscopic measurements support tetranuclear structure for all of them. Electronic spectra in the near infrared with high molecular absorptivity may be explained for tetranuclear cuban structure to fulfil 3 halo-ligands for each copper centre in [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>]. The EPR spectra for [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] complexes are axial type of spectra (d<sub>x2-y2</sub> G.S) suggesting elongated tetragonal distortion for all of them. Cyclic voltammograms for [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] are irreversible in character. These tetranuclear carbonato complexes show catalytical activity. They initiate the oxidation of 2,6-dimethylphenol (DMP) to 3,3’,5,5’-tetramethyl-4,4’-diphenoquinone (DPQ).
文摘A tetranuclear Ln(Ⅲ)-based complex:[Dy_(4)(dbm)_(4)(L)_(6)(μ_(3)-OH)_(2)]·CH_(3)CN(1)(HL=5-[(4-methylbenzylidene)amino]quinolin-8-ol,Hdbm=dibenzoylmethane)was manufactured and its structure was characterized in detail.Xray diffraction analysis shows that complex 1 belongs to the monoclinic crystal system and its space group is P2_1/n,which contains a rhombic Dy_(4)core.Magnetic measurements of 1 suggest it possesses extraordinary single-molecule magnet(SMM)behavior.Its energy barrier U_(eff)/k_(B)was 116.7 K,and the pre-exponential coefficient τ_(0)=1.05×10~(-8)s.CCDC:2359322.
基金Supported by the National Natural Science Foundation of China(No.21372051,61671162)the Science and Technology Planning Project of Guangdong Province(No.2013B021700001,2016A010103031)+1 种基金the Excellent Young Teacher Development Project of Universities in Guangdong Province(No.261532106)the Guangzhou Science and Technology Program(No.502150105)
文摘One novel Co(II) coordination polymer, namely [Co4(L)6(NO3)2] (1) was prepared by solvothermal reactions of Co(NO3)2 with a (E)-2-[2-(3-thienyl)ethenyl]-8-quinolinol ligand (HL), which has been determined by single-crystal X-ray diffraction analyses and further characterized by means of elemental analyses, IR spectra, PXRD and thermogravimetric analyses (TGA). The core structure of complex 1 is an incomplete dicubane-like tetranuclear Co(II) cluster, which is surrounded by six 8-hydroxy-quinolinate-based ligands and two nitrate ligands. Weak S-O interactions between the thienyl groups and nitrate ligands extend the adjacent tetranuclear CoOI) clusters into a supramolecular (4, 4) net structure. Magnetic measurement indicates that the coupling within both molecules is overall antiferromagnetic.
基金The project was supported by the Education Office of Jilin Province (No. 0047)
文摘A metal-organic coordination polymer [ZnE.s(phen)(BDC)2(OH)]2 (phen = 1,10- phenanthroline, BDC = benzene-1,4-dicarboxylic acid) 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The complex crystallizes in the triclinic system, space group PI with a = 11.199(2), b = 11.593(2), c = 11.865(3)/A, α= 99.330(1), β = 111.506(1), γ = 104.804(1)^o, V= 1328.4(5)A^3, Dc= 1.722 g/cm^3, Z = 1, Mr = 1377.82, F(000) = 692,μ(MoKa) = 2.306 mm^-1, S = 1.093, R= 0.0281 and wR = 0.0756 for 4179 observed reflections (I 〉 2σ(/)). The coordination polyhedron around Zn(II) can be described as a tetrahedron, trigonal bipyramid and octahedron. It is worth noting that the crystal structure of 1 is composed of tetranuclear zinc clusters linked by {ZnO6} units.
文摘An O-Vanillin-methionine Schiff Base complex with copper(Ⅱ) has been synthesized under a mild condition. The complex has been characterized by elemental analysis, UV, FT-IR, TG-DTA and XRD. The crystal structure of the complex belongs to monoclinic, with space group C2/C, a=2.070 4(12) nm, b=1.431 9(8) nm, c=2.812 9(11) nm, β=133.15(2)°, V=6.084(5) nm 3, Z=8, D c= 0.998 Mg/m 3, F(000)=1 836, final R=0.121 8. The results revealed it is a tetranuclear copper(Ⅱ) complex.
文摘A tetranuclear Mn(Ⅳ) complex \{\[L\-4Mn\-4O\-6\]\}(ClO\-4)\-4\52H\-2O (L=tacn)was synthesized from Mn(CH\-3COO)\-2\54H\-2O, tacn and NaClO\-4 and characterized by XRD. The compound crystallizes in monoclinic system, space group P2\-1/n , with a =2.133 5(6) nm, b =1.138 7(3) nm, \{ c =\}\{2.178 8(6) nm\}, β =67.40(3)°, V =4.928(2) nm 3 , Z =4, R =0.062 0. Magnetic investigations reveal a weak ferromagnetic property with J =8.8 cm -1 .