An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-o...An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.展开更多
The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2...The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2Mo(μ_3-CC_6H_5) Br(CO)_9(Py)_2 (3) and Mn_2Mo(μ_3-CC_6H_5)Br(CO)_(10) (Py)_2 (4) respectively. Tri-metal cluster compound Co_2Mo(μ_3-CC_6H_5)Br(CO)_8-(bipy) (bipy=α,α'dipyridyl) (5) is prepared in a similar reaction sequence from [Br(CO)_2(bipy)Mo(≡CC_6H_5)] (1b) and Co_2(CO)_8. IR, ~1H and ^(13)C NMR spectral data of these compounds are reported and discussed. The crystal structure of compound (5) has been determined by X-ray diffraction.展开更多
The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of...The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of pure (CH_3CH_2)_3N and thiophenol, these values are moved to high position, and the width of these peaks is obviously increased. These characteristics conformed to NMR spectra of paramagnetic compounds and their molecular structures. The paramagnetic property of these compounds was also studied with ESR spectrum. Mass spectra of three compounds were determined. The main fragments were observed, for example, m/z: 130〔(C_2H_5)_4N〕+, 264〔Fe_3S_3〕+, 144〔Fe-S-Fe〕+, 120〔S-Fe-S〕+, 88〔Fe-S〕+, 136〔FeBr〕+, 91〔FeCl〕+ etc. These supported structural characteristics of the anion skeleton and molecules strongly. The possible mechanism of fragmentation was discussed.展开更多
The cluster compound[Mo_4S_4(μ-O_2CC_5H_5)_2(dtp)_4](dtp=S_2P(OEt)_2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo_4S_4(μ-dtp)_2(dtp)_4]in the mixed solvent of acetone,ethan...The cluster compound[Mo_4S_4(μ-O_2CC_5H_5)_2(dtp)_4](dtp=S_2P(OEt)_2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo_4S_4(μ-dtp)_2(dtp)_4]in the mixed solvent of acetone,ethanol and water in the presence of C_6H_5CO_2Na.It is monoclinic and crystallizes in space group C2/c, Mr=1495.09,a=12.175(5),b=22.01(1),c=20.875(9),β=99.04(4)°;V=5575(5);Z=4; Dc=1.78g/cm^3.Final R factor is 0.066.The result reveals that the[Mo_4S_4]cluster core and t-(dtp)^(-1)ligands are retained and only μ-bridged(dtp)^(-1)ligands are substituted by(C_6H_5CO_2)^(-1)in the substitution reaction,thus producing the new title cluster compound,the structure of which contains two species of bidentate ligand.展开更多
Sodium molybdate was reduced to produce ring-like compounds in the presence of carboxylic acids. Compound 1: Na8(H2O)28(H3O)+{Na(DMSO)2[MoVI10MoV8O52(OH)4(CH3C- OO)2]}11H2O (C8H103O102Na9S2Mo18, Mr = 3829.85), where ...Sodium molybdate was reduced to produce ring-like compounds in the presence of carboxylic acids. Compound 1: Na8(H2O)28(H3O)+{Na(DMSO)2[MoVI10MoV8O52(OH)4(CH3C- OO)2]}11H2O (C8H103O102Na9S2Mo18, Mr = 3829.85), where the {Mo18} ring is built up by two acetic acids connecting two {Mo9} building blocks and the 1-D chain of 1 is formed through the coordinated sodium cations. Crystal data: triclinic, space group P, a = 11.3228(2), b = 15.4170(2), c = 16.7209(3) ? a = 113.006(1), b = 108.455(1), g = 92.430(1), V = 2501.98(7) 3, Z = 1, Dc = 2.542 g/cm3, F(000) = 1854, (MoKa) = 2.381 mm-1, T = 293(2) K, final R = 0.0532 and wR = 0.1203 for 7291 observed reflections with I > 2(I) from 8775 independent reflections. Compound 2: Na8(H2O)22(H3O)+{Na(DMSO)2[MoVI10MoV8O52(OH)4(C2H5COO)2]}10H2O (C10H93O94Na9- S2Mo18, Mr = 3715.79). Crystal data: monoclinic, space group C2/m, a = 18.044(1), b = 25.944(2), c = 10.4087(6) ? b = 106.613(2), V = 4669.3(5) 3, Z = 2, Dc = 2.643 g/cm3, F(000) = 3584, (MoKa) = 2.542 mm-1, T = 293(2) K, final R = 0.0536 and wR = 0.1621 for 4617 observed reflections with I > 2(I) from 5398 independent reflections. Similar to 1, the {Mo18} ring is built up by two {Mo9} building blocks that are connected up by two propanoic acids and these {Mo18} rings are further linked into a two-dimensional layer through the coordinated sodium cations.展开更多
The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0....The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0.5] （2） （bipy = 4,4＇-bipyridine, bix = 1,4-bis（imidazole-1-ylmethyl）benzene）. Both compounds were catalytically active and stable for the epoxidation of cyclooctene, 1-octene, and styrene with tert-butyl hydroperoxide （t-BuOOH） as oxidant. The excellent catalytic performance was attributed to the presence of stable coordination bonds between the molybdenum oxide and copper complex, which resulted in the formation of easily accessible Mo species with high electropositivity. In addition, the copper complex also acted as an active site for the activation of t-BuOOH, thus im- proving these copper complex-modified polyoxometalates.展开更多
This paper presents the synthetic and structure studies of molybdenum（tungsten）-copper-sulphur-dialkyldithiocarbamate cluster compounds.The reactions of（M=Mo,W;n=0,2）,CuCl,and R<sub>2</sub>dtc￣-（R<...This paper presents the synthetic and structure studies of molybdenum（tungsten）-copper-sulphur-dialkyldithiocarbamate cluster compounds.The reactions of（M=Mo,W;n=0,2）,CuCl,and R<sub>2</sub>dtc￣-（R<sub>2</sub>=Me<sub>2</sub>,Et<sub>2</sub>,C<sub>4</sub>H<sub>8</sub>,C<sub>5</sub>H<sub>1</sub>0） yield a series of tetra-,hexa-,and heptanuclear cluster compounds.Their spectroscopic properties and the synthetic reaction mechanism are discussed.展开更多
A novel classification scheme for inorganic cluster compounds is presented based on the characteristics of their electronic structures.In the classification scheme,five distinct categories have been introduced,includi...A novel classification scheme for inorganic cluster compounds is presented based on the characteristics of their electronic structures.In the classification scheme,five distinct categories have been introduced,including Jellium clusters,Wadian clusters,electron-precise clusters,π-donor ligated metal-metal bonded clusters,and antiferro-magnetically coupled high-spin metal clusters.展开更多
Reactions of [NH_4]_2[MS_4](M=Mo,W),CuX(X=Br,I)and PPh_3 in the solid state produced four mixed-metal sulfur containing clusters{Cu_3MS_3X}(PPh_3)_3S(M=Mo,W;X=Br,I),two of which (1:M=Mo,X=I;2:M=W,X=Br)were structurall...Reactions of [NH_4]_2[MS_4](M=Mo,W),CuX(X=Br,I)and PPh_3 in the solid state produced four mixed-metal sulfur containing clusters{Cu_3MS_3X}(PPh_3)_3S(M=Mo,W;X=Br,I),two of which (1:M=Mo,X=I;2:M=W,X=Br)were structurally determined.Crystals of 1 and 2 are triclinic, space group P(1:a=11.895(3),b=13.107(1),c=20.473(2),α=74.95(6),β=84.87(8),γ=64.27(7)°, Z=2,V=2776.1 ,Rw=0.064 for 6443 observed reflections.2:α=11.876 (1),b=13.065 (2),c= 20.325(2),α=74.95(1),β=85.39(1),γ=64.09(1)°,Z=2,V=2737.3,R_w=0.055 for 5303 observed reflections).The results of the structure determination showed that the central units of the two cubane- like cluster compounds are composed of four metal atoms and four non-metal atoms situated at alter- nate comers.The differences of cubane-like cluster compounds obtained from solid state reactions and from solution reactions are discussed.展开更多
The title compound was prepared by the reaction of Mo_3S_4(dtp)_4(H_2O)[ctp=S_2P(OEt)_2] with NaOAc·3H_2O and C_4H_8NCS_2NH_4.Crystallographic data:[Mo_3(μ_3-S)(μ-S)_2(μ-OAc)- (S_2CNC_4H_8)_3(O)_2]·0.5CH_...The title compound was prepared by the reaction of Mo_3S_4(dtp)_4(H_2O)[ctp=S_2P(OEt)_2] with NaOAc·3H_2O and C_4H_8NCS_2NH_4.Crystallographic data:[Mo_3(μ_3-S)(μ-S)_2(μ-OAc)- (S_2CNC_4H_8)_3(O)_2]·0.5CH_2CI_2·2H_2O,Mr=980.18,triclinic,space group P(?),α=12.360(3),b=16.653(6), c=9.206(2)A,α=101.97(2),β=108.32(2),γ=86.14(3)°.V=1759.6(9)A^3,Z=2,Dc=1.85 g/cm^3, F(000)=962,μ(Mo K_α)=16.53 cm^(-1).Final R=0.044 for 4301 reflections with I≥3σ(I).This compound may be regarded as a mixed-valent trinuclear molybdenum cluster{Mo_2(V)Mo(Ⅳ)(μ_3-S)(μ-S)_2- (μ-OAc)(S_2CNC_4H_8)_3(O)_2}.The Mo-Mo distances are 2.783(1),2.833(1)and 3.374(2)A in the Mo_3 non-equilateral triangle and there exist only two Mo-Mo bonds.The cluster was obtained by oxi- dation and ligand substitution of{Mo_3(μ_3-S)(μ-S)_3[μ-S_2P(OEt_2)][S_2P(OEt)_2]_3(H_2O)}.展开更多
The compound(n-Bu_4N)_2[W_2Cu_4S_8(S_2CNC_4H_8)_2]was obtained by the reaction of Bu_4NBr, (NH_4)_2WS_4,NaS_2NCC_4H_8 and CuCl in CH_3CN and CH_3OH.It crystallizes in the monoclinic space group P2_1/c with unit cell p...The compound(n-Bu_4N)_2[W_2Cu_4S_8(S_2CNC_4H_8)_2]was obtained by the reaction of Bu_4NBr, (NH_4)_2WS_4,NaS_2NCC_4H_8 and CuCl in CH_3CN and CH_3OH.It crystallizes in the monoclinic space group P2_1/c with unit cell parameters:a=21.875(5),b=16.843(4),c=17.745(5)(?),β= 101.69(6)°,V=6402(6)(?)~3,Z=4,D_o=1.718 g·cm^(-3).The final R and R_w values converged to 0.055 and 0.060 respectively.The structure consists of two‘butterfly’units[WS_4Cu_2]linked together by two weak Cu—S bonds and two bridging S_2CNC_4H_8 ligands.Infrared spectra gave charac- teristic absorptions at 495 cm^(-1) for W=S and 450,435,412 cm^(-1) for W—μ-S.展开更多
Co_6(μ_3-S)_8(Ph_2PCH_2P(O)Ph_2)_6, MW=3012.5, space group R, has the hexagonal parameters, a=26.764(10), c=16.979 (10), V=10532.8~3, Z=3. Mo Kα radiation, λ= 0.71069, Dc=1.425 g/cm^3, μ=9.94 cm^(-3), F(000)=4650,...Co_6(μ_3-S)_8(Ph_2PCH_2P(O)Ph_2)_6, MW=3012.5, space group R, has the hexagonal parameters, a=26.764(10), c=16.979 (10), V=10532.8~3, Z=3. Mo Kα radiation, λ= 0.71069, Dc=1.425 g/cm^3, μ=9.94 cm^(-3), F(000)=4650, R=0.073 and Rw=0.077 for 1965 observed unique reflections with I>3σ(I). The molecular structure consists of a distorted octahed- ral Co_6-core. The Co-Co and Co-S distances fall in the range of 2.805-2.838 and 2.213-2.253, respectively.展开更多
The electronic structures of six cubane-like cluster compounds of the type[Fe_4S_4L_4]~n (L=SH,OH,and CI,n=-2 and -3;L=NO,n=0 and -1)have been calculated by using DV-X_α method,and the bonding properties are discusse...The electronic structures of six cubane-like cluster compounds of the type[Fe_4S_4L_4]~n (L=SH,OH,and CI,n=-2 and -3;L=NO,n=0 and -1)have been calculated by using DV-X_α method,and the bonding properties are discussed with emphasis on the ligand effect on cluster bonding. The comparisons of MO energies and cluster charge distributions with the experimental data are made, and the differences between the early studies and the present one are also briefly commented.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
The [Zr6(μ2-Cl)12Cl6H4]3- ion with C4v Symmetry in the title compounds has been calculated by DV-Xα program. The calculated results show that ther is almost no available covalence bonding between zirconium ato...The [Zr6(μ2-Cl)12Cl6H4]3- ion with C4v Symmetry in the title compounds has been calculated by DV-Xα program. The calculated results show that ther is almost no available covalence bonding between zirconium atoms and significant Zr 4d AO compositions in the MOs. but there are much stronger Zr-Cl(bridging) bonding. All analysis results suggest that these compounds would be the cluster with Zr6Cl12 cage linked by Zr-Cl bridging bonding plus six Cl teminal ligands rather than the hexazirconium cluster in view of the chemical bonding.展开更多
The electronic structures of rare earth cluster halides R(R_6X_(12)) and their interstitial compounds R_7X_(12)Z were studied by the DV-X_(?) method (R=Sc,Y,Pr,Gd or Er;X=Cl,Br or I;Z=B,C,N,Fe,Co or Ru).The results sh...The electronic structures of rare earth cluster halides R(R_6X_(12)) and their interstitial compounds R_7X_(12)Z were studied by the DV-X_(?) method (R=Sc,Y,Pr,Gd or Er;X=Cl,Br or I;Z=B,C,N,Fe,Co or Ru).The results show that because f electrons in empty rare earth cluster are screened,their orbitals are more difficult to overlap each other,a deficiency of skeleton orbitals in cluster causing the system to be unstable.They are easily condensed into chain compound R_2X_3 or R_5X_8.If a light atom of main group is embedded into octahedral cluster,bonding orbitals formed from interstitial atom and rare earth cluster strengthen cluster skeleton bond in the system to reach structural stability.If embedded atom belongs to transition metal,bonding orbitals composed of that of interstitial atom and rare earth cluster take the place of original cluster skeleton orbitals to form heteronuclear metal cluster (or double-coordination compound).展开更多
By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L...By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L12 Al3Ti-base intermetallic compound. The results are presented using the density of states (DOS) and one-electron properties, such as relative binding tendency between the atom and the model cluster, and hybrid bonding tendency between the alloying element and the host atoms. By comparing the four models of Ti4Al14X cluster, the effect of the Fe, Ni or Cu atom on the physical properties of Al3Ti-based L12 intermetallic compounds is analyzed. The results indicate that the addition of the Fe, Ni or Cu atom intensifies the relative binding tendency between Ti atom and Ti4Al14X cluster. It was found that the Fermi level (EF) lies in a maximum in the DOS for Ti4Al14Al cluster; on the contrary, the EF comes near a minimum tn the DOS for Ti4Al14X (X=Fe, Ni and Cu) cluster. Thus the L12 crystal structure for binary Al3Ti alloy is unstable, and the addition of the Fe, Ni or Cu atom to Al3Ti is benefical to stabilize L12 crystal structure. The calculation also shows that the Fe, Ni or Cu atom strengthens the hybrid bonding tendency between the central atom and the host atoms for Ti4Al14X cluster and thereby may lead to the constriction of the lattice of Al3Ti-base intermetallic compounds.展开更多
The heterotrinuclear cluster compound [MoW<sub>2</sub>O<sub>2</sub> （O<sub>2</sub>CC<sub>2</sub>H<sub>5</sub> ）<sub>6</sub>-（ H<sub>2<...The heterotrinuclear cluster compound [MoW<sub>2</sub>O<sub>2</sub> （O<sub>2</sub>CC<sub>2</sub>H<sub>5</sub> ）<sub>6</sub>-（ H<sub>2</sub>O）<sub>3</sub>] ZnBr4·4H<sub>2</sub>O was prepared by the redox reaction of Mo （CO）<sub>6</sub> with Na<sub>2</sub>W<sub>O</sub>4 in propionic anhydride. The crystal is monoclinic of space group P2/c with a =16. 334（4） , b= 9. 657（5） , c=19. 889（9） ,β= 139. 79 （5）°,V= 2026 （2） ￣3 , Z=2 , D<sub>c</sub>=2. 30 g/cm￣3 μ（MoKa） =106. 6 cm￣（-1） ,F（000）=1176 ,final R=0. 065 and R<sub>ω</sub>=0. 072 for 1964 reflections with I≥3σ（I）. In the structure of cation [MoW<sub>2</sub>O<sub>2</sub> （O<sub>2</sub>CC<sub>2</sub>H<sub>5</sub> ）<sub>6</sub> （H<sub>2</sub>O）<sub>3</sub>]￣（2+） molybdenum and tungsten atoms are statistically disordered. Three metal atoms form an equilateral triangle with the distance of M-M being 2. 735.展开更多
A new heptanuclear trigonal prismatic cluster [PrCu6(μ3-OH)3(Gly)6im6](ClO4)6 was synthesized through the self-assembly of Pr3+, Cu2+, glycine and imidazole in aqueous solution and characterized by X-ray structure ...A new heptanuclear trigonal prismatic cluster [PrCu6(μ3-OH)3(Gly)6im6](ClO4)6 was synthesized through the self-assembly of Pr3+, Cu2+, glycine and imidazole in aqueous solution and characterized by X-ray structure analysis. The compound belongs to the trigonal R3 space group with a = b = 15.8761(2), c = 23.4943(5) ?, V = 5128.4(1) ?3, Z = 3, Dc = 1.965 g/cm3, μ = 2.869 mm-1, F(000) = 3012, the final R = 0.0332 and wR = 0.0844 for 3596 independent reflections. In the cation, the Pr3+ ion is situated at the center of a prism formed by six copper atoms and coordinates to nine oxygen atoms with a tricapped trigonal prismatic coordination polyhedron. Six glycine ligands and six imidazole terminal ligands participate in constructing the cluster.展开更多
A new tetranuclear square compound （H3O）[Sm2Co2（CDTA）2（DMF）2 （μ4-O） （H2O）6]ClO4 was synthesized through the assembly reaction of Co2＋ , Sm3＋ and trans-1,2-cclohexylenedinitrilotetraacetic acid （H4CDTA） ...A new tetranuclear square compound （H3O）[Sm2Co2（CDTA）2（DMF）2 （μ4-O） （H2O）6]ClO4 was synthesized through the assembly reaction of Co2＋ , Sm3＋ and trans-1,2-cclohexylenedinitrilotetraacetic acid （H4CDTA） in aqueous solution. X-ray crystal structural analysis shows that the compound belongs to the monoclinic C2/c space group, with a=27.213（2）, b=10.5574（9）, c=19.4923（17）,β=98.799（1）°, V=5534.1（8）3 , C34H65ClCo2N6O30Sm2 , Mr=1491.93, Dc=1.791g/cm-3 , F（000）=2984,=2.820 mm-1 and Z=4. In the compound, Co2＋ is 7-coordianted while Sm3＋ is 9-coordinated. With the help of a central O2- and 8 carboxylate oxygen atoms, two Co2＋ and two Sm3＋ ions are linked into a square with the side length of 3.45 . Magnetic property was investigated.展开更多
文摘An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.
文摘The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2Mo(μ_3-CC_6H_5) Br(CO)_9(Py)_2 (3) and Mn_2Mo(μ_3-CC_6H_5)Br(CO)_(10) (Py)_2 (4) respectively. Tri-metal cluster compound Co_2Mo(μ_3-CC_6H_5)Br(CO)_8-(bipy) (bipy=α,α'dipyridyl) (5) is prepared in a similar reaction sequence from [Br(CO)_2(bipy)Mo(≡CC_6H_5)] (1b) and Co_2(CO)_8. IR, ~1H and ^(13)C NMR spectral data of these compounds are reported and discussed. The crystal structure of compound (5) has been determined by X-ray diffraction.
文摘The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of pure (CH_3CH_2)_3N and thiophenol, these values are moved to high position, and the width of these peaks is obviously increased. These characteristics conformed to NMR spectra of paramagnetic compounds and their molecular structures. The paramagnetic property of these compounds was also studied with ESR spectrum. Mass spectra of three compounds were determined. The main fragments were observed, for example, m/z: 130〔(C_2H_5)_4N〕+, 264〔Fe_3S_3〕+, 144〔Fe-S-Fe〕+, 120〔S-Fe-S〕+, 88〔Fe-S〕+, 136〔FeBr〕+, 91〔FeCl〕+ etc. These supported structural characteristics of the anion skeleton and molecules strongly. The possible mechanism of fragmentation was discussed.
文摘The cluster compound[Mo_4S_4(μ-O_2CC_5H_5)_2(dtp)_4](dtp=S_2P(OEt)_2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo_4S_4(μ-dtp)_2(dtp)_4]in the mixed solvent of acetone,ethanol and water in the presence of C_6H_5CO_2Na.It is monoclinic and crystallizes in space group C2/c, Mr=1495.09,a=12.175(5),b=22.01(1),c=20.875(9),β=99.04(4)°;V=5575(5);Z=4; Dc=1.78g/cm^3.Final R factor is 0.066.The result reveals that the[Mo_4S_4]cluster core and t-(dtp)^(-1)ligands are retained and only μ-bridged(dtp)^(-1)ligands are substituted by(C_6H_5CO_2)^(-1)in the substitution reaction,thus producing the new title cluster compound,the structure of which contains two species of bidentate ligand.
基金the National Natural Science Foundation of China (20073048),NSF of Fujian province (2002F015) and the Chinese Academy of Sciences
文摘Sodium molybdate was reduced to produce ring-like compounds in the presence of carboxylic acids. Compound 1: Na8(H2O)28(H3O)+{Na(DMSO)2[MoVI10MoV8O52(OH)4(CH3C- OO)2]}11H2O (C8H103O102Na9S2Mo18, Mr = 3829.85), where the {Mo18} ring is built up by two acetic acids connecting two {Mo9} building blocks and the 1-D chain of 1 is formed through the coordinated sodium cations. Crystal data: triclinic, space group P, a = 11.3228(2), b = 15.4170(2), c = 16.7209(3) ? a = 113.006(1), b = 108.455(1), g = 92.430(1), V = 2501.98(7) 3, Z = 1, Dc = 2.542 g/cm3, F(000) = 1854, (MoKa) = 2.381 mm-1, T = 293(2) K, final R = 0.0532 and wR = 0.1203 for 7291 observed reflections with I > 2(I) from 8775 independent reflections. Compound 2: Na8(H2O)22(H3O)+{Na(DMSO)2[MoVI10MoV8O52(OH)4(C2H5COO)2]}10H2O (C10H93O94Na9- S2Mo18, Mr = 3715.79). Crystal data: monoclinic, space group C2/m, a = 18.044(1), b = 25.944(2), c = 10.4087(6) ? b = 106.613(2), V = 4669.3(5) 3, Z = 2, Dc = 2.643 g/cm3, F(000) = 3584, (MoKa) = 2.542 mm-1, T = 293(2) K, final R = 0.0536 and wR = 0.1621 for 4617 observed reflections with I > 2(I) from 5398 independent reflections. Similar to 1, the {Mo18} ring is built up by two {Mo9} building blocks that are connected up by two propanoic acids and these {Mo18} rings are further linked into a two-dimensional layer through the coordinated sodium cations.
基金supported by the National Natural Science Foundation of China(21173100 and 21320102001)~~
文摘The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0.5] （2） （bipy = 4,4＇-bipyridine, bix = 1,4-bis（imidazole-1-ylmethyl）benzene）. Both compounds were catalytically active and stable for the epoxidation of cyclooctene, 1-octene, and styrene with tert-butyl hydroperoxide （t-BuOOH） as oxidant. The excellent catalytic performance was attributed to the presence of stable coordination bonds between the molybdenum oxide and copper complex, which resulted in the formation of easily accessible Mo species with high electropositivity. In addition, the copper complex also acted as an active site for the activation of t-BuOOH, thus im- proving these copper complex-modified polyoxometalates.
文摘This paper presents the synthetic and structure studies of molybdenum（tungsten）-copper-sulphur-dialkyldithiocarbamate cluster compounds.The reactions of（M=Mo,W;n=0,2）,CuCl,and R<sub>2</sub>dtc￣-（R<sub>2</sub>=Me<sub>2</sub>,Et<sub>2</sub>,C<sub>4</sub>H<sub>8</sub>,C<sub>5</sub>H<sub>1</sub>0） yield a series of tetra-,hexa-,and heptanuclear cluster compounds.Their spectroscopic properties and the synthetic reaction mechanism are discussed.
基金supported by the Research Grants Council of Hong Kong(HKUST 16302222).
文摘A novel classification scheme for inorganic cluster compounds is presented based on the characteristics of their electronic structures.In the classification scheme,five distinct categories have been introduced,including Jellium clusters,Wadian clusters,electron-precise clusters,π-donor ligated metal-metal bonded clusters,and antiferro-magnetically coupled high-spin metal clusters.
基金Project supported by the National Natural Science Foundation of China and the State Education Commission of China
文摘Reactions of [NH_4]_2[MS_4](M=Mo,W),CuX(X=Br,I)and PPh_3 in the solid state produced four mixed-metal sulfur containing clusters{Cu_3MS_3X}(PPh_3)_3S(M=Mo,W;X=Br,I),two of which (1:M=Mo,X=I;2:M=W,X=Br)were structurally determined.Crystals of 1 and 2 are triclinic, space group P(1:a=11.895(3),b=13.107(1),c=20.473(2),α=74.95(6),β=84.87(8),γ=64.27(7)°, Z=2,V=2776.1 ,Rw=0.064 for 6443 observed reflections.2:α=11.876 (1),b=13.065 (2),c= 20.325(2),α=74.95(1),β=85.39(1),γ=64.09(1)°,Z=2,V=2737.3,R_w=0.055 for 5303 observed reflections).The results of the structure determination showed that the central units of the two cubane- like cluster compounds are composed of four metal atoms and four non-metal atoms situated at alter- nate comers.The differences of cubane-like cluster compounds obtained from solid state reactions and from solution reactions are discussed.
基金Work supported by the National Natural Science Foundation of China.
文摘The title compound was prepared by the reaction of Mo_3S_4(dtp)_4(H_2O)[ctp=S_2P(OEt)_2] with NaOAc·3H_2O and C_4H_8NCS_2NH_4.Crystallographic data:[Mo_3(μ_3-S)(μ-S)_2(μ-OAc)- (S_2CNC_4H_8)_3(O)_2]·0.5CH_2CI_2·2H_2O,Mr=980.18,triclinic,space group P(?),α=12.360(3),b=16.653(6), c=9.206(2)A,α=101.97(2),β=108.32(2),γ=86.14(3)°.V=1759.6(9)A^3,Z=2,Dc=1.85 g/cm^3, F(000)=962,μ(Mo K_α)=16.53 cm^(-1).Final R=0.044 for 4301 reflections with I≥3σ(I).This compound may be regarded as a mixed-valent trinuclear molybdenum cluster{Mo_2(V)Mo(Ⅳ)(μ_3-S)(μ-S)_2- (μ-OAc)(S_2CNC_4H_8)_3(O)_2}.The Mo-Mo distances are 2.783(1),2.833(1)and 3.374(2)A in the Mo_3 non-equilateral triangle and there exist only two Mo-Mo bonds.The cluster was obtained by oxi- dation and ligand substitution of{Mo_3(μ_3-S)(μ-S)_3[μ-S_2P(OEt_2)][S_2P(OEt)_2]_3(H_2O)}.
基金Project supported by the National Natural Science Foundation of Chinathe Natural Science Foundation of Chinese Academy of Sciencesthe Science Foundation for Youth.
文摘The compound(n-Bu_4N)_2[W_2Cu_4S_8(S_2CNC_4H_8)_2]was obtained by the reaction of Bu_4NBr, (NH_4)_2WS_4,NaS_2NCC_4H_8 and CuCl in CH_3CN and CH_3OH.It crystallizes in the monoclinic space group P2_1/c with unit cell parameters:a=21.875(5),b=16.843(4),c=17.745(5)(?),β= 101.69(6)°,V=6402(6)(?)~3,Z=4,D_o=1.718 g·cm^(-3).The final R and R_w values converged to 0.055 and 0.060 respectively.The structure consists of two‘butterfly’units[WS_4Cu_2]linked together by two weak Cu—S bonds and two bridging S_2CNC_4H_8 ligands.Infrared spectra gave charac- teristic absorptions at 495 cm^(-1) for W=S and 450,435,412 cm^(-1) for W—μ-S.
基金Project supported by the National Natural Science Foundation of China.
文摘Co_6(μ_3-S)_8(Ph_2PCH_2P(O)Ph_2)_6, MW=3012.5, space group R, has the hexagonal parameters, a=26.764(10), c=16.979 (10), V=10532.8~3, Z=3. Mo Kα radiation, λ= 0.71069, Dc=1.425 g/cm^3, μ=9.94 cm^(-3), F(000)=4650, R=0.073 and Rw=0.077 for 1965 observed unique reflections with I>3σ(I). The molecular structure consists of a distorted octahed- ral Co_6-core. The Co-Co and Co-S distances fall in the range of 2.805-2.838 and 2.213-2.253, respectively.
基金This work is financially supported by the National Natural Science Foundation of China.
文摘The electronic structures of six cubane-like cluster compounds of the type[Fe_4S_4L_4]~n (L=SH,OH,and CI,n=-2 and -3;L=NO,n=0 and -1)have been calculated by using DV-X_α method,and the bonding properties are discussed with emphasis on the ligand effect on cluster bonding. The comparisons of MO energies and cluster charge distributions with the experimental data are made, and the differences between the early studies and the present one are also briefly commented.
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.
文摘The [Zr6(μ2-Cl)12Cl6H4]3- ion with C4v Symmetry in the title compounds has been calculated by DV-Xα program. The calculated results show that ther is almost no available covalence bonding between zirconium atoms and significant Zr 4d AO compositions in the MOs. but there are much stronger Zr-Cl(bridging) bonding. All analysis results suggest that these compounds would be the cluster with Zr6Cl12 cage linked by Zr-Cl bridging bonding plus six Cl teminal ligands rather than the hexazirconium cluster in view of the chemical bonding.
基金The project supported by the National Natural Science Foundation of China
文摘The electronic structures of rare earth cluster halides R(R_6X_(12)) and their interstitial compounds R_7X_(12)Z were studied by the DV-X_(?) method (R=Sc,Y,Pr,Gd or Er;X=Cl,Br or I;Z=B,C,N,Fe,Co or Ru).The results show that because f electrons in empty rare earth cluster are screened,their orbitals are more difficult to overlap each other,a deficiency of skeleton orbitals in cluster causing the system to be unstable.They are easily condensed into chain compound R_2X_3 or R_5X_8.If a light atom of main group is embedded into octahedral cluster,bonding orbitals formed from interstitial atom and rare earth cluster strengthen cluster skeleton bond in the system to reach structural stability.If embedded atom belongs to transition metal,bonding orbitals composed of that of interstitial atom and rare earth cluster take the place of original cluster skeleton orbitals to form heteronuclear metal cluster (or double-coordination compound).
文摘By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L12 Al3Ti-base intermetallic compound. The results are presented using the density of states (DOS) and one-electron properties, such as relative binding tendency between the atom and the model cluster, and hybrid bonding tendency between the alloying element and the host atoms. By comparing the four models of Ti4Al14X cluster, the effect of the Fe, Ni or Cu atom on the physical properties of Al3Ti-based L12 intermetallic compounds is analyzed. The results indicate that the addition of the Fe, Ni or Cu atom intensifies the relative binding tendency between Ti atom and Ti4Al14X cluster. It was found that the Fermi level (EF) lies in a maximum in the DOS for Ti4Al14Al cluster; on the contrary, the EF comes near a minimum tn the DOS for Ti4Al14X (X=Fe, Ni and Cu) cluster. Thus the L12 crystal structure for binary Al3Ti alloy is unstable, and the addition of the Fe, Ni or Cu atom to Al3Ti is benefical to stabilize L12 crystal structure. The calculation also shows that the Fe, Ni or Cu atom strengthens the hybrid bonding tendency between the central atom and the host atoms for Ti4Al14X cluster and thereby may lead to the constriction of the lattice of Al3Ti-base intermetallic compounds.
文摘The heterotrinuclear cluster compound [MoW<sub>2</sub>O<sub>2</sub> （O<sub>2</sub>CC<sub>2</sub>H<sub>5</sub> ）<sub>6</sub>-（ H<sub>2</sub>O）<sub>3</sub>] ZnBr4·4H<sub>2</sub>O was prepared by the redox reaction of Mo （CO）<sub>6</sub> with Na<sub>2</sub>W<sub>O</sub>4 in propionic anhydride. The crystal is monoclinic of space group P2/c with a =16. 334（4） , b= 9. 657（5） , c=19. 889（9） ,β= 139. 79 （5）°,V= 2026 （2） ￣3 , Z=2 , D<sub>c</sub>=2. 30 g/cm￣3 μ（MoKa） =106. 6 cm￣（-1） ,F（000）=1176 ,final R=0. 065 and R<sub>ω</sub>=0. 072 for 1964 reflections with I≥3σ（I）. In the structure of cation [MoW<sub>2</sub>O<sub>2</sub> （O<sub>2</sub>CC<sub>2</sub>H<sub>5</sub> ）<sub>6</sub> （H<sub>2</sub>O）<sub>3</sub>]￣（2+） molybdenum and tungsten atoms are statistically disordered. Three metal atoms form an equilateral triangle with the distance of M-M being 2. 735.
基金This research was supported by the State Key Laboratory of Structural Chemistry the National Science and Technology of China (001CB1089)+8 种基金 the Chinese Academy of Sciences (CAS) the National Science Foundation of China (20333070 2027307390206040) and the Science Foundation of CAS and Fujian Province (2002F0142003J0422004J0412004H201-1)
文摘A new heptanuclear trigonal prismatic cluster [PrCu6(μ3-OH)3(Gly)6im6](ClO4)6 was synthesized through the self-assembly of Pr3+, Cu2+, glycine and imidazole in aqueous solution and characterized by X-ray structure analysis. The compound belongs to the trigonal R3 space group with a = b = 15.8761(2), c = 23.4943(5) ?, V = 5128.4(1) ?3, Z = 3, Dc = 1.965 g/cm3, μ = 2.869 mm-1, F(000) = 3012, the final R = 0.0332 and wR = 0.0844 for 3596 independent reflections. In the cation, the Pr3+ ion is situated at the center of a prism formed by six copper atoms and coordinates to nine oxygen atoms with a tricapped trigonal prismatic coordination polyhedron. Six glycine ligands and six imidazole terminal ligands participate in constructing the cluster.
基金Supported by the NNSFC (21071025, 91122031)Doctoral Fund of Ministry of Education of China (20100041120021)DUT (893127 and 851004)
文摘A new tetranuclear square compound （H3O）[Sm2Co2（CDTA）2（DMF）2 （μ4-O） （H2O）6]ClO4 was synthesized through the assembly reaction of Co2＋ , Sm3＋ and trans-1,2-cclohexylenedinitrilotetraacetic acid （H4CDTA） in aqueous solution. X-ray crystal structural analysis shows that the compound belongs to the monoclinic C2/c space group, with a=27.213（2）, b=10.5574（9）, c=19.4923（17）,β=98.799（1）°, V=5534.1（8）3 , C34H65ClCo2N6O30Sm2 , Mr=1491.93, Dc=1.791g/cm-3 , F（000）=2984,=2.820 mm-1 and Z=4. In the compound, Co2＋ is 7-coordianted while Sm3＋ is 9-coordinated. With the help of a central O2- and 8 carboxylate oxygen atoms, two Co2＋ and two Sm3＋ ions are linked into a square with the side length of 3.45 . Magnetic property was investigated.
