The electric pulse modification （EP, EPM） of liquid metal is a novel method for grain refinement. The structure of EP-modified Al-5%Cu melt was characterized by high-temperature X-ray diffractometry. The results sho...The electric pulse modification （EP, EPM） of liquid metal is a novel method for grain refinement. The structure of EP-modified Al-5%Cu melt was characterized by high-temperature X-ray diffractometry. The results show that the Cu-containing Al clusters remarkably increase in the EP-modified melt, furthermore, these clusters in that case tend to contract due to the decrease of relevant atomic radius and the co-ordination number. This kind of liquid-phase structure leads to a more homogeneous Cu-rich phase distribution in the final solidification structure. Differential scanning calorimetry （DSC） tests indicate that the solidification super-cooling degree of the EP-modified liquid phase is 2.36 times that of the unmodified. These facts suggest that the atom cluster changes in EP-modified Al-5%Cu melt would disagree with that by EPM model previously proposed in liquid pure metal.展开更多
The heterotrinuclear cluster compound [MoW_2O_2 (O_2CC_2H_5 )_6-( H_2O)_3] ZnBr4·4H_2O was prepared by the redox reaction of Mo (CO)_6 with Na_2W_O4 in propionic anhydride. The crystal is monoclinic of space grou...The heterotrinuclear cluster compound [MoW_2O_2 (O_2CC_2H_5 )_6-( H_2O)_3] ZnBr4·4H_2O was prepared by the redox reaction of Mo (CO)_6 with Na_2W_O4 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_c=2. 30 g/cm￣3 μ(MoKa) =106. 6 cm￣(-1) ,F(000)=1176 ,final R=0. 065 and R_ω=0. 072 for 1964 reflections with I≥3σ(I). In the structure of cation [MoW_2O_2 (O_2CC_2H_5 )_6 (H_2O)_3]￣(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
Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent years.However,developing USCAD catalysts with high-density metal sites anchored ...Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent years.However,developing USCAD catalysts with high-density metal sites anchored in porous nanomaterials is still challenging.Here,through the template-free S-assisted pyrolysis of low-cost Fe-salts with melamine(MA),porous alveolate Fe/g-C3N4 catalysts with high-density(Fe loading up to 17.7 wt%)and increased USCAD Fe sites were synthesized.The presence of a certain amount of S species in the Fe-salts/MA system plays an important role in the formation of USCAD S-Fe-salt/CN catalysts;the S species act as a"sacrificial carrier"to increase the dispersion of Fe species through Fe-S coordination and generate porous alveolate structure by escaping in the form of SO2 during pyrolysis.The S-Fe-salt/CN catalysts exhibit greatly promoted activity and reusability for degrading various organic pollutants in advanced oxidation processes compared to the corresponding Fe-salt/CN catalysts,due to the promoted accessibility of USCAD Fe sites by the porous alveolate structure.This S-assisted method exhibits good feasibility in a large variety of S species(thiourea,S powder,and NH4SCN)and Fe salts,providing a new avenue for the low-cost and large-scale synthesis of high-density USCAD metal/g-C3N4 catalysts.展开更多
The title compound 〔(PPh 3)(CH 3COS) 2NiB 10 H 10 〕·0.4(C 5H 12 ) has been synthesized by the reaction of 〔NiCl 2(PPh 3) 2〕, closo 〔B 10 H 10 〕 2- and CH 3COSH in CH 2Cl 2 solution. It was recrystallized fr...The title compound 〔(PPh 3)(CH 3COS) 2NiB 10 H 10 〕·0.4(C 5H 12 ) has been synthesized by the reaction of 〔NiCl 2(PPh 3) 2〕, closo 〔B 10 H 10 〕 2- and CH 3COSH in CH 2Cl 2 solution. It was recrystallized from n pentane/CH 2Cl 2 solution and its structure was determined by X ray diffraction analysis. The crystal is triclinic, space group P1, M r= 618.23, with a=10.049(1), b=12.638(2), c=14.077(2) , α=110.13(1), β=87.65(1), γ=96.01(1)°, V=1669.3(4) 3, D c =1.230 g/cm 3, Z=2, λ (Mo Kα )=0.71073 , μ =7.76 cm -1 , F (000)=642. The final refinement is converged with R =0.042 (5986 observed reflections with I≥2σ(I)), wR 2 =0.151. The cluster is a nido eleven vertex {NiB 10 } cage with the Ni atom in the open NiB 4 face. Cyclizations resulting in two five membered rings, Ni(7)-S(1)-C(1)-O(1)-B(2) and Ni(7)-S(2)-C(2)-O(2)-B(3), have occurred.展开更多
A new mixed-metal sulfido incomplete cubane cluster [(MoCuS3) (O) (μ-dtp) (PPh3)3] Cdtp = S2P (OC2H5)2] has been prepared by reaction of (NH4)2MoOS3 with Cu(dtp) (PPh3)2 in dimethylformamide solution. It crystallizes...A new mixed-metal sulfido incomplete cubane cluster [(MoCuS3) (O) (μ-dtp) (PPh3)3] Cdtp = S2P (OC2H5)2] has been prepared by reaction of (NH4)2MoOS3 with Cu(dtp) (PPh3)2 in dimethylformamide solution. It crystallizes in the triclinic space group P1, a = 13.810(5), b = 19. 753(5), c=11. 719(4) A. α=99. 42(2), β=107. 24(3),γ=88. 05(3)°, V = 3012(2)A3, Dc = l. 51g/cm3and Z = 2. Final R=0. 046, Rw = 0. 056 for 7700 unique intensity data(I≥3σ(I)). The central unit [MoCu3S3]3+ can be described as a distorted incomplete cube with one missing corner. The Mo atom is tetrahedrally coordinated by three μ3-S atoms and one terminal O atom. Two Cu atoms are tetrahedrally coordinated whereas the third Cu atom has a highly distorted trigonal environment. The mean Mo - Cu bond length is 2. 752A. The Cu...Cu distances are in the range of 3. 200(1) -3. 740(1) A which are too long to form bonds.展开更多
The reaction of μ alkyne bridged dimolybdenum compound 〔Mo 2( μ C 2HPh)(CO) 4( η 5 C 5H 4C(O)Me) 2〕 1 with Co 2(CO) 8 in refluxing toluene gave a new butterfly compound 〔Co 2Mo 2( μ 4 C 2HPh)( μ CO) 4(CO) 4( ...The reaction of μ alkyne bridged dimolybdenum compound 〔Mo 2( μ C 2HPh)(CO) 4( η 5 C 5H 4C(O)Me) 2〕 1 with Co 2(CO) 8 in refluxing toluene gave a new butterfly compound 〔Co 2Mo 2( μ 4 C 2HPh)( μ CO) 4(CO) 4( η 5 C 5H 4C(O)Me) 2〕 2 which was fully characterized by elemental analysis, IR, 1H NMR and X ray single crystal diffraction techniques. 2 crystallized in monoclinic system, C 30 H 20 Co 2Mo 2O 10 , M r =850.23, space group P2 1/a(#14), a=14.165(5), b=12.498(2), c=16.204(2) , β = 96 50(2)°, V = 2850(1) 3, Z = 4, D c = 1.981 g cm -3 , F(000)=1672, μ (Mo Kα )=20.41 cm -1 , final R=0.030, R w =0.039 for 4831 observable reflections with I>2σ(I ). The structure contains a Co 2Mo 2 butterfly core, and each Mo-Co bond is spanned by an asymmetric semi bridging carbonyl ligand.展开更多
The cluster compound [Mo4S4 (μ-O2CC6H5)2(dtp)4] (dtp = S2P (OEt)2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo4S4(μ-dtp)2(dtp)4] in the mixed solvent of acetone, ethanol an...The cluster compound [Mo4S4 (μ-O2CC6H5)2(dtp)4] (dtp = S2P (OEt)2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo4S4(μ-dtp)2(dtp)4] in the mixed solvent of acetone, ethanol and water in the presence of C6H5CO2Na. It is monoclinic and crystallizesin space group C2/c, Mr =1495. 09, a=12. 175 (5) , b=22. 01 (1) , c=20.875(9) ,β=99. 04(4)°; V=5570(5) ; Z=4; Dc= 1. 78g/cm3;μ(MoKα) = 14. 52 cm-1; F(000) =2984. Final R factor is 0. 066. The result reveals that the [Mo4S4] cluster core and t-(dtp)1ligands are retained and onlyμ-bridged (dtp)1- ligands are substituted by (C6H5CO2)1in the substitution reaction, thus producing the title cluster compound,the structure of which contains two species of bidentate ligand.展开更多
The cubane-type mixed Mo W cluster[Mo2W2S4 (OAc)2(dtp)3 (dtpH)]·CH2Cl2 (dtp= (EtO)2PS2, dtpH = (EtO)2PS (SH) has been prepared by reduction and addition reaction between dinuclear W2S4 (dtp)2 and Mo(CO)6 in HOAc...The cubane-type mixed Mo W cluster[Mo2W2S4 (OAc)2(dtp)3 (dtpH)]·CH2Cl2 (dtp= (EtO)2PS2, dtpH = (EtO)2PS (SH) has been prepared by reduction and addition reaction between dinuclear W2S4 (dtp)2 and Mo(CO)6 in HOAc and Ac2O solution in the presence of dtp-ligand. Crystallographic data: Mr=1632. 71,monoclinic, space group P2/n, a=13. 146 (8), b=11. 961 (5),c=17. 157 (9) β =105. 99(8)°, V=2593(8), Z=2, Dc=2. 09 /cm￣3 ,λ(MoKa) =0.71073 ,F (000)=1578, final R=0. 029, Rw = 0. 041 for 3765 unique intensity data [I≥4σ (I)]. The result of X-ray study and elemental analysis indicated that, in the crystal lattice, molybdenum and tungsten are statistically distributed in the metal positions each with 0. 5 fractional occupation.展开更多
The title complex C CrMo3 (μ3-O )3 (μ-O) (μ-O2CCH3 )5 (O2CCH3)3]2Na2 · H2O (Mr=1814. 32) crystallizes in monoclinic, space group P21/ n with a=11.209(5), b=18. 05(1), c=14. 44(1) A , β= 98. 30(5)°. V=289...The title complex C CrMo3 (μ3-O )3 (μ-O) (μ-O2CCH3 )5 (O2CCH3)3]2Na2 · H2O (Mr=1814. 32) crystallizes in monoclinic, space group P21/ n with a=11.209(5), b=18. 05(1), c=14. 44(1) A , β= 98. 30(5)°. V=2890 (3) A3, Z=2, A = 2. 08 g/cm3, F(000) -1780, Final R = 0. 049, Rw = 0. 058 for 2622 independent reflectons with I>3σ(I). The complex anion contains two Mo3O4 cores which connect two chromium atoms through four μ3-O atoms and eight bridging CH3COO- groups. Each of the Cr atoms and the Mo atoms is coordinated by six oxygen atoms. The anions are linked by Na cations to form one-dimensional infinite chain structure.展开更多
A new heterometallic cluster W2Ag2S4(tdt)2(PPh3)2·CH2Cl2(H2tdt=H2CH3C6H3S2)(Ⅱ) has been prepared from the reaction of a well-defined molecular building block W2S4(tdt)22-(I) with Ag complex. The compound has bee...A new heterometallic cluster W2Ag2S4(tdt)2(PPh3)2·CH2Cl2(H2tdt=H2CH3C6H3S2)(Ⅱ) has been prepared from the reaction of a well-defined molecular building block W2S4(tdt)22-(I) with Ag complex. The compound has been characterized by X-ray diffraction study, IR., UV-Vis Spectroscopy and cyclic voltammetry.Crystallographic data for the compound are: space group P21/n,a=17.234(4), b=17.622(4), c=19. 094(4) A,β= 99. 22(2)°,V=5704(2) A3, Z=4,final R=0. 042 and Rw=0. 049 for 5983 independent reflections with I≥3σ(I) The structure analysis reveals that the cluster contains a cubane-like core [W2Ag2S4]4+ . The coordination geometry of each tungsten atom is a square pyramid just as that in the building block. Two types of metal-metal bonds of W-W bond and W-Ag bond exist in the core. The distance between two Ag atoms is out of the range of bonding.展开更多
The chiral cluster RuCoMo（CO）8 （μ3-Se）C5H4C （O）C6H4C （O）OCH3was synthesizgd by the thermal reaction of the precursor （μ3-Se）RuCo2（Co）9 with ’thefunctionally substituted cyclopentadienyl tricarbonyl meta...The chiral cluster RuCoMo（CO）8 （μ3-Se）C5H4C （O）C6H4C （O）OCH3was synthesizgd by the thermal reaction of the precursor （μ3-Se）RuCo2（Co）9 with ’thefunctionally substituted cyclopentadienyl tricarbonyl metal complex anions [Mo（CO）3（η5-C5H4） C （O）C6H4C （O） OCH3]- in THF. It was characterized by C/H elementalanalysis, IR, 1H/13C-NMR and MS （FAB）, and its crystal structure has also beensolved by single-crystal X-ray diffraction. Crystal data: Mr=786. 23, triclinic, spacegroup P1, a =8. 200（2）, b= 19. 631 （7）, c=7.997（2） , a=92. 50（2）, β=108. 66 （2）, γ=88. 97（2）°, V= 1218. 5（6） , Z=2, Dc=2. 143g/cm3, F（000） =756. 00, μ= 33. 44cm-1, the final R =0. 054 and R.= 0. 077 for 2644 observationswith （I≥3.0σ（I） ）.展开更多
The syntheses and structures of trinuclear Mo (W)-Fe-S cluster[MFe2S2(CO)8 (S,CNSEt2)]- (M=Mo, W), hexanuclear Fe-S cluster [Fe6S6-(CO)12]2- and undecanuclear Cu-Fe-S cluster [Cu5Fe6S6(CO)18(PPh3)2]-, containingFe2S2(...The syntheses and structures of trinuclear Mo (W)-Fe-S cluster[MFe2S2(CO)8 (S,CNSEt2)]- (M=Mo, W), hexanuclear Fe-S cluster [Fe6S6-(CO)12]2- and undecanuclear Cu-Fe-S cluster [Cu5Fe6S6(CO)18(PPh3)2]-, containingFe2S2(CO)6-units bave been summarized and the important vestiges left in their struc-tures reflecting the formation processes of the clusters have been found and discussed.Further inspecting some other typical clusters a regular unit construction in the forma-tion of the metal cluster compounds containing Fe2S2(CO)6-units has been figured outand applied to speculate and predict several new cluster compounds containing Fe2S2(CO)6-units.展开更多
The reaction of dipropargyl phthalate C6H41,2(CO2CH2C2H)2 1 with octacarbonyldicobalt 2 resulted in the formation of red complex C6H41,2(CO2CH2C2H)2Co2(CO)62 3, in which each Co2(CO)6 group coordinates to one of t...The reaction of dipropargyl phthalate C6H41,2(CO2CH2C2H)2 1 with octacarbonyldicobalt 2 resulted in the formation of red complex C6H41,2(CO2CH2C2H)2Co2(CO)62 3, in which each Co2(CO)6 group coordinates to one of the two CC bonds of 1. Molecular structure of complex 3 was determined by single crystal Xray analyses. The crystal belongs to the monoclinic system, space group P21/a with the following crystallographic parameters: a=8.521(2), b=29.143(6), c=12.918(7) , = 100.12(3),V=3158(2) 3, Z=4, Mr=814.09, Dc=1712 g.cm-3, F(000)=1608, (MoK)=21.37 cm-1 and final R=0.044 for 3151 observations.展开更多
The title compound {Mo3 (μ3,-S) (μ-S)3 [μ-SOP (OEt )2] [S2P (OEt)2]3(CH3CN) }. CH3CN, C20H46,Mo3N2O9P4S11, Mr= 1222. 9, has been synthesized bythe reaction of [Mo3 (μ3,-S) (μ-S)3]4+ with Hdtp (hydrogen diethyldit...The title compound {Mo3 (μ3,-S) (μ-S)3 [μ-SOP (OEt )2] [S2P (OEt)2]3(CH3CN) }. CH3CN, C20H46,Mo3N2O9P4S11, Mr= 1222. 9, has been synthesized bythe reaction of [Mo3 (μ3,-S) (μ-S)3]4+ with Hdtp (hydrogen diethyldithiophosphate)and its structures was dctermined by X-ray crystallography. The crystal data for the title compound: triclinic, P1, Z= 2, a= 13. 011 (8), b= 13. 411 (9), c= 14. 385 (5)A, a=76. 59(5), B=78. 09(5), Y=82. 20(3), V= 2382(2) A3, Dc= 1.705 g/cm3, μ (MoKa) = 1. 434 mm-1, F (000) = 1228. The structure was refined to R =0.080 for 5485 observed reflections. Quasi-aromaticity in the puckered-ring of Mo3S3was experimentally probed by 31p NMR spectroscopic measurements. The 31p chemicalshifts of ligand DTP’s (diethyldithiophosphate) were modulated by the substituent effect of the adjacent bridging aromatic carboxylate through the long-distance super-conjugation via the trinuclear Mo cluster core.展开更多
round-the-clock solar observations with full-disk coverage of vector magnetograms and multi-wavelength images demonstrate that solar active regions(ARs) are ultimately connected with magnetic field. Often two or more ...round-the-clock solar observations with full-disk coverage of vector magnetograms and multi-wavelength images demonstrate that solar active regions(ARs) are ultimately connected with magnetic field. Often two or more ARs are clustered, creating a favorable magnetic environment for the onset of coronal mass ejections(CMEs). In this work, we describe a new type of magnetic complex: cluster of solar ARs. An AR cluster is referred to as the close connection of two or more ARs which are located in nearly the same latitude and a narrow span of longitude. We illustrate three examples of AR clusters, each of which has two ARs connected and formed a common dome of magnetic flux system. They are clusters of NOAA(i.e., National Oceanic and Atmospheric Administration) ARs 11226 & 11227, 11429 & 11430, and 11525 & 11524. In these AR clusters, CME initiations were often tied to the instability of the magnetic structures connecting two partner ARs, in the form of inter-connecting loops and/or channeling filaments between the two ARs. We show the evidence that, at least, some of the flare/CMEs in an AR cluster are not a phenomenon of a single AR, but the result of magnetic interaction in the whole AR cluster. The observations shed new light on understanding the mechanism(s) of solar activity. Instead of the simple bipolar topology as suggested by the so-called standard flare model, a multi-bipolar magnetic topology is more common to host the violent solar activity in solar atmosphere.展开更多
Based on the short-range order,it is found that the abundance of the P-centered P-transition-metal clusters are the common feature among the liquid Pd-Cu-Ni-P alloys,and hence this feature alone could not uncover the ...Based on the short-range order,it is found that the abundance of the P-centered P-transition-metal clusters are the common feature among the liquid Pd-Cu-Ni-P alloys,and hence this feature alone could not uncover the underlying mechanisms of the variation of glass forming ability among the liquid alloys.For the so called similar elements such as Cu and Ni,their behaviors are significantly different when interacting with Pd or P atoms.Cu has weak bonding with both Pd and P while Ni has very strong bonding with P but nearly no bonding with Pd.The different bonding characters thus underlie the phenomenon that in the best glass formers the ratio of the two similar elements often deviates from 1:1.Only if the parameters of chemical short-range order of Cu and Ni around P become closest to each other the best glass forming ability is reached.It is also illustrated that the calculated dynamic properties are very helpful to locate the composition of the best glass former.展开更多
基金Project(51074087)supported by the National Natural Science Foundation of ChinaProject(201102088)supported by the Natural Science Foundation of Liaoning Province,China+1 种基金Project(LJQ2011065)supported by Liaoning Excellent Talents in University,ChinaProject(2010921096)supported by Liaoning Baiqianwan Talents Program,China
文摘The electric pulse modification （EP, EPM） of liquid metal is a novel method for grain refinement. The structure of EP-modified Al-5%Cu melt was characterized by high-temperature X-ray diffractometry. The results show that the Cu-containing Al clusters remarkably increase in the EP-modified melt, furthermore, these clusters in that case tend to contract due to the decrease of relevant atomic radius and the co-ordination number. This kind of liquid-phase structure leads to a more homogeneous Cu-rich phase distribution in the final solidification structure. Differential scanning calorimetry （DSC） tests indicate that the solidification super-cooling degree of the EP-modified liquid phase is 2.36 times that of the unmodified. These facts suggest that the atom cluster changes in EP-modified Al-5%Cu melt would disagree with that by EPM model previously proposed in liquid pure metal.
文摘The heterotrinuclear cluster compound [MoW_2O_2 (O_2CC_2H_5 )_6-( H_2O)_3] ZnBr4·4H_2O was prepared by the redox reaction of Mo (CO)_6 with Na_2W_O4 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_c=2. 30 g/cm￣3 μ(MoKa) =106. 6 cm￣(-1) ,F(000)=1176 ,final R=0. 065 and R_ω=0. 072 for 1964 reflections with I≥3σ(I). In the structure of cation [MoW_2O_2 (O_2CC_2H_5 )_6 (H_2O)_3]￣(2+) molybdenum and tungsten atoms are statistically disordered. Three metal atoms form an equilateral triangle with the distance of M-M being 2. 735.
文摘Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent years.However,developing USCAD catalysts with high-density metal sites anchored in porous nanomaterials is still challenging.Here,through the template-free S-assisted pyrolysis of low-cost Fe-salts with melamine(MA),porous alveolate Fe/g-C3N4 catalysts with high-density(Fe loading up to 17.7 wt%)and increased USCAD Fe sites were synthesized.The presence of a certain amount of S species in the Fe-salts/MA system plays an important role in the formation of USCAD S-Fe-salt/CN catalysts;the S species act as a"sacrificial carrier"to increase the dispersion of Fe species through Fe-S coordination and generate porous alveolate structure by escaping in the form of SO2 during pyrolysis.The S-Fe-salt/CN catalysts exhibit greatly promoted activity and reusability for degrading various organic pollutants in advanced oxidation processes compared to the corresponding Fe-salt/CN catalysts,due to the promoted accessibility of USCAD Fe sites by the porous alveolate structure.This S-assisted method exhibits good feasibility in a large variety of S species(thiourea,S powder,and NH4SCN)and Fe salts,providing a new avenue for the low-cost and large-scale synthesis of high-density USCAD metal/g-C3N4 catalysts.
文摘The title compound 〔(PPh 3)(CH 3COS) 2NiB 10 H 10 〕·0.4(C 5H 12 ) has been synthesized by the reaction of 〔NiCl 2(PPh 3) 2〕, closo 〔B 10 H 10 〕 2- and CH 3COSH in CH 2Cl 2 solution. It was recrystallized from n pentane/CH 2Cl 2 solution and its structure was determined by X ray diffraction analysis. The crystal is triclinic, space group P1, M r= 618.23, with a=10.049(1), b=12.638(2), c=14.077(2) , α=110.13(1), β=87.65(1), γ=96.01(1)°, V=1669.3(4) 3, D c =1.230 g/cm 3, Z=2, λ (Mo Kα )=0.71073 , μ =7.76 cm -1 , F (000)=642. The final refinement is converged with R =0.042 (5986 observed reflections with I≥2σ(I)), wR 2 =0.151. The cluster is a nido eleven vertex {NiB 10 } cage with the Ni atom in the open NiB 4 face. Cyclizations resulting in two five membered rings, Ni(7)-S(1)-C(1)-O(1)-B(2) and Ni(7)-S(2)-C(2)-O(2)-B(3), have occurred.
文摘A new mixed-metal sulfido incomplete cubane cluster [(MoCuS3) (O) (μ-dtp) (PPh3)3] Cdtp = S2P (OC2H5)2] has been prepared by reaction of (NH4)2MoOS3 with Cu(dtp) (PPh3)2 in dimethylformamide solution. It crystallizes in the triclinic space group P1, a = 13.810(5), b = 19. 753(5), c=11. 719(4) A. α=99. 42(2), β=107. 24(3),γ=88. 05(3)°, V = 3012(2)A3, Dc = l. 51g/cm3and Z = 2. Final R=0. 046, Rw = 0. 056 for 7700 unique intensity data(I≥3σ(I)). The central unit [MoCu3S3]3+ can be described as a distorted incomplete cube with one missing corner. The Mo atom is tetrahedrally coordinated by three μ3-S atoms and one terminal O atom. Two Cu atoms are tetrahedrally coordinated whereas the third Cu atom has a highly distorted trigonal environment. The mean Mo - Cu bond length is 2. 752A. The Cu...Cu distances are in the range of 3. 200(1) -3. 740(1) A which are too long to form bonds.
文摘The reaction of μ alkyne bridged dimolybdenum compound 〔Mo 2( μ C 2HPh)(CO) 4( η 5 C 5H 4C(O)Me) 2〕 1 with Co 2(CO) 8 in refluxing toluene gave a new butterfly compound 〔Co 2Mo 2( μ 4 C 2HPh)( μ CO) 4(CO) 4( η 5 C 5H 4C(O)Me) 2〕 2 which was fully characterized by elemental analysis, IR, 1H NMR and X ray single crystal diffraction techniques. 2 crystallized in monoclinic system, C 30 H 20 Co 2Mo 2O 10 , M r =850.23, space group P2 1/a(#14), a=14.165(5), b=12.498(2), c=16.204(2) , β = 96 50(2)°, V = 2850(1) 3, Z = 4, D c = 1.981 g cm -3 , F(000)=1672, μ (Mo Kα )=20.41 cm -1 , final R=0.030, R w =0.039 for 4831 observable reflections with I>2σ(I ). The structure contains a Co 2Mo 2 butterfly core, and each Mo-Co bond is spanned by an asymmetric semi bridging carbonyl ligand.
文摘The cluster compound [Mo4S4 (μ-O2CC6H5)2(dtp)4] (dtp = S2P (OEt)2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo4S4(μ-dtp)2(dtp)4] in the mixed solvent of acetone, ethanol and water in the presence of C6H5CO2Na. It is monoclinic and crystallizesin space group C2/c, Mr =1495. 09, a=12. 175 (5) , b=22. 01 (1) , c=20.875(9) ,β=99. 04(4)°; V=5570(5) ; Z=4; Dc= 1. 78g/cm3;μ(MoKα) = 14. 52 cm-1; F(000) =2984. Final R factor is 0. 066. The result reveals that the [Mo4S4] cluster core and t-(dtp)1ligands are retained and onlyμ-bridged (dtp)1- ligands are substituted by (C6H5CO2)1in the substitution reaction, thus producing the title cluster compound,the structure of which contains two species of bidentate ligand.
文摘The cubane-type mixed Mo W cluster[Mo2W2S4 (OAc)2(dtp)3 (dtpH)]·CH2Cl2 (dtp= (EtO)2PS2, dtpH = (EtO)2PS (SH) has been prepared by reduction and addition reaction between dinuclear W2S4 (dtp)2 and Mo(CO)6 in HOAc and Ac2O solution in the presence of dtp-ligand. Crystallographic data: Mr=1632. 71,monoclinic, space group P2/n, a=13. 146 (8), b=11. 961 (5),c=17. 157 (9) β =105. 99(8)°, V=2593(8), Z=2, Dc=2. 09 /cm￣3 ,λ(MoKa) =0.71073 ,F (000)=1578, final R=0. 029, Rw = 0. 041 for 3765 unique intensity data [I≥4σ (I)]. The result of X-ray study and elemental analysis indicated that, in the crystal lattice, molybdenum and tungsten are statistically distributed in the metal positions each with 0. 5 fractional occupation.
文摘The title complex C CrMo3 (μ3-O )3 (μ-O) (μ-O2CCH3 )5 (O2CCH3)3]2Na2 · H2O (Mr=1814. 32) crystallizes in monoclinic, space group P21/ n with a=11.209(5), b=18. 05(1), c=14. 44(1) A , β= 98. 30(5)°. V=2890 (3) A3, Z=2, A = 2. 08 g/cm3, F(000) -1780, Final R = 0. 049, Rw = 0. 058 for 2622 independent reflectons with I>3σ(I). The complex anion contains two Mo3O4 cores which connect two chromium atoms through four μ3-O atoms and eight bridging CH3COO- groups. Each of the Cr atoms and the Mo atoms is coordinated by six oxygen atoms. The anions are linked by Na cations to form one-dimensional infinite chain structure.
文摘A new heterometallic cluster W2Ag2S4(tdt)2(PPh3)2·CH2Cl2(H2tdt=H2CH3C6H3S2)(Ⅱ) has been prepared from the reaction of a well-defined molecular building block W2S4(tdt)22-(I) with Ag complex. The compound has been characterized by X-ray diffraction study, IR., UV-Vis Spectroscopy and cyclic voltammetry.Crystallographic data for the compound are: space group P21/n,a=17.234(4), b=17.622(4), c=19. 094(4) A,β= 99. 22(2)°,V=5704(2) A3, Z=4,final R=0. 042 and Rw=0. 049 for 5983 independent reflections with I≥3σ(I) The structure analysis reveals that the cluster contains a cubane-like core [W2Ag2S4]4+ . The coordination geometry of each tungsten atom is a square pyramid just as that in the building block. Two types of metal-metal bonds of W-W bond and W-Ag bond exist in the core. The distance between two Ag atoms is out of the range of bonding.
文摘The chiral cluster RuCoMo（CO）8 （μ3-Se）C5H4C （O）C6H4C （O）OCH3was synthesizgd by the thermal reaction of the precursor （μ3-Se）RuCo2（Co）9 with ’thefunctionally substituted cyclopentadienyl tricarbonyl metal complex anions [Mo（CO）3（η5-C5H4） C （O）C6H4C （O） OCH3]- in THF. It was characterized by C/H elementalanalysis, IR, 1H/13C-NMR and MS （FAB）, and its crystal structure has also beensolved by single-crystal X-ray diffraction. Crystal data: Mr=786. 23, triclinic, spacegroup P1, a =8. 200（2）, b= 19. 631 （7）, c=7.997（2） , a=92. 50（2）, β=108. 66 （2）, γ=88. 97（2）°, V= 1218. 5（6） , Z=2, Dc=2. 143g/cm3, F（000） =756. 00, μ= 33. 44cm-1, the final R =0. 054 and R.= 0. 077 for 2644 observationswith （I≥3.0σ（I） ）.
文摘The syntheses and structures of trinuclear Mo (W)-Fe-S cluster[MFe2S2(CO)8 (S,CNSEt2)]- (M=Mo, W), hexanuclear Fe-S cluster [Fe6S6-(CO)12]2- and undecanuclear Cu-Fe-S cluster [Cu5Fe6S6(CO)18(PPh3)2]-, containingFe2S2(CO)6-units bave been summarized and the important vestiges left in their struc-tures reflecting the formation processes of the clusters have been found and discussed.Further inspecting some other typical clusters a regular unit construction in the forma-tion of the metal cluster compounds containing Fe2S2(CO)6-units has been figured outand applied to speculate and predict several new cluster compounds containing Fe2S2(CO)6-units.
文摘The reaction of dipropargyl phthalate C6H41,2(CO2CH2C2H)2 1 with octacarbonyldicobalt 2 resulted in the formation of red complex C6H41,2(CO2CH2C2H)2Co2(CO)62 3, in which each Co2(CO)6 group coordinates to one of the two CC bonds of 1. Molecular structure of complex 3 was determined by single crystal Xray analyses. The crystal belongs to the monoclinic system, space group P21/a with the following crystallographic parameters: a=8.521(2), b=29.143(6), c=12.918(7) , = 100.12(3),V=3158(2) 3, Z=4, Mr=814.09, Dc=1712 g.cm-3, F(000)=1608, (MoK)=21.37 cm-1 and final R=0.044 for 3151 observations.
文摘The title compound {Mo3 (μ3,-S) (μ-S)3 [μ-SOP (OEt )2] [S2P (OEt)2]3(CH3CN) }. CH3CN, C20H46,Mo3N2O9P4S11, Mr= 1222. 9, has been synthesized bythe reaction of [Mo3 (μ3,-S) (μ-S)3]4+ with Hdtp (hydrogen diethyldithiophosphate)and its structures was dctermined by X-ray crystallography. The crystal data for the title compound: triclinic, P1, Z= 2, a= 13. 011 (8), b= 13. 411 (9), c= 14. 385 (5)A, a=76. 59(5), B=78. 09(5), Y=82. 20(3), V= 2382(2) A3, Dc= 1.705 g/cm3, μ (MoKa) = 1. 434 mm-1, F (000) = 1228. The structure was refined to R =0.080 for 5485 observed reflections. Quasi-aromaticity in the puckered-ring of Mo3S3was experimentally probed by 31p NMR spectroscopic measurements. The 31p chemicalshifts of ligand DTP’s (diethyldithiophosphate) were modulated by the substituent effect of the adjacent bridging aromatic carboxylate through the long-distance super-conjugation via the trinuclear Mo cluster core.
基金supported by the National Natural Science Foundation of China(Grant Nos.11221063,11373004,11322329,41404150,and 11303049)Ministry of Science and Technology(Grant No.2011CB811403)
文摘round-the-clock solar observations with full-disk coverage of vector magnetograms and multi-wavelength images demonstrate that solar active regions(ARs) are ultimately connected with magnetic field. Often two or more ARs are clustered, creating a favorable magnetic environment for the onset of coronal mass ejections(CMEs). In this work, we describe a new type of magnetic complex: cluster of solar ARs. An AR cluster is referred to as the close connection of two or more ARs which are located in nearly the same latitude and a narrow span of longitude. We illustrate three examples of AR clusters, each of which has two ARs connected and formed a common dome of magnetic flux system. They are clusters of NOAA(i.e., National Oceanic and Atmospheric Administration) ARs 11226 & 11227, 11429 & 11430, and 11525 & 11524. In these AR clusters, CME initiations were often tied to the instability of the magnetic structures connecting two partner ARs, in the form of inter-connecting loops and/or channeling filaments between the two ARs. We show the evidence that, at least, some of the flare/CMEs in an AR cluster are not a phenomenon of a single AR, but the result of magnetic interaction in the whole AR cluster. The observations shed new light on understanding the mechanism(s) of solar activity. Instead of the simple bipolar topology as suggested by the so-called standard flare model, a multi-bipolar magnetic topology is more common to host the violent solar activity in solar atmosphere.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50971082 and 50831003)
文摘Based on the short-range order,it is found that the abundance of the P-centered P-transition-metal clusters are the common feature among the liquid Pd-Cu-Ni-P alloys,and hence this feature alone could not uncover the underlying mechanisms of the variation of glass forming ability among the liquid alloys.For the so called similar elements such as Cu and Ni,their behaviors are significantly different when interacting with Pd or P atoms.Cu has weak bonding with both Pd and P while Ni has very strong bonding with P but nearly no bonding with Pd.The different bonding characters thus underlie the phenomenon that in the best glass formers the ratio of the two similar elements often deviates from 1:1.Only if the parameters of chemical short-range order of Cu and Ni around P become closest to each other the best glass forming ability is reached.It is also illustrated that the calculated dynamic properties are very helpful to locate the composition of the best glass former.
