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
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
(Et4N)[Mo3(μ3-O)(μ-Cl)3(μ-OAc)3Cl3], C14H29Cl6Mo3NO7, Mr = 823.92, triclinic, P1, a = 17. 508(4), b = 19. 602(3), c=8. 091(2)A, α=91. 25(2)°, β= 96. 56(2)°,γ= 83. 61(2)°, V = 2741(1)A3, Z = 4, Dc ...(Et4N)[Mo3(μ3-O)(μ-Cl)3(μ-OAc)3Cl3], C14H29Cl6Mo3NO7, Mr = 823.92, triclinic, P1, a = 17. 508(4), b = 19. 602(3), c=8. 091(2)A, α=91. 25(2)°, β= 96. 56(2)°,γ= 83. 61(2)°, V = 2741(1)A3, Z = 4, Dc = 2.00g/cm3, MoKa (λ=0. 71069A), μ= 19. 44cm-1, F(000) = 1616, T = 23℃, final R = 0. 055, Rw = 0. 068 for 5728 unique intensity data (I≥3σ(I)).The molecule consists of cluster aniorn [Mo3(μ3-O) (μ-Cl)3(μ-OAc)3Cl3]- and cation (Et4N) + . There are two independent molecules in an asymmetric unit whose cluster anions A and B have the same configuration except for some bonding parameters. The cluster core may be described as an equilateral {Mo3} triangle with a capping O atom and three bridging Cl atoms below and above it respectively. In addition, each pair of Mo atoms is bridged by an acetate group and each Mo atom is further coordinated to a terminal chlorine atom. The three Mo - Mo bonds are 2. 587 (2), 2.587(2), 2. 582(2) A for cluster anion A and 2. 587(2), 2.595(2), 2.577 (2) A for cluster anion B. Altogether eight, d electrons occupy the {Mo3} cluster bonding orbitals.展开更多
Magnetic susceptibility of a series of dinuclear Ⅴ(Ⅳ) . Co(Ⅱ) and Mn(Ⅲ) complexes has been measured in the temperature range of 1. 5 ～300K. The isotropic Heisenberg theory has been applied to study the temperatur...Magnetic susceptibility of a series of dinuclear Ⅴ(Ⅳ) . Co(Ⅱ) and Mn(Ⅲ) complexes has been measured in the temperature range of 1. 5 ～300K. The isotropic Heisenberg theory has been applied to study the temperature-dependent behaviour of the magnetic susceptibility of these complexes and a corresponding program for fitting the experimental results has been set up on a VAX 11/785 computer. Conclusions can be drawn that the three complexes studied are all anti-ferromagnetically coupled with coupling constants -4. 4 , -115. 2 , and - 8. 4 cm￣(-1) for Ⅴ(Ⅳ) . Co(Ⅱ) ,and Mn(Ⅲ) complexes, respectively.展开更多
The title compound [Cu(dtp) PPh3]2 (dtp=S2,P(OEt)2) was prepared by heating the mononuclear compound Cu(dtp)(PPh3)2 in CH3CN solution.It crystallizes in the triclinic space group P1 with parameters a=9.71 6(5),b=11.02...The title compound [Cu(dtp) PPh3]2 (dtp=S2,P(OEt)2) was prepared by heating the mononuclear compound Cu(dtp)(PPh3)2 in CH3CN solution.It crystallizes in the triclinic space group P1 with parameters a=9.71 6(5),b=11.026(5),c=12.475(4) A.α=78.16(3)°,β=102. 64(4), γ=114.34(4)°,V=1178(1)A 3,Z=1,Dc=1.44 g/cm3,MoKα(λ=0.71069 A) μ=12. 48cm-1,F(000)=528.Final R=0.041.Rω= 0. 052 for 3653 unique intensity data(I≥3σ(I)).The molecule of the title compound can be viewed as a centrosymmetric dimer with two[Cu(dtp)(PPh3)] units,which are bridged by two S atoms belonging to the dtp ligands.The exact planar[Cu2S2] core and two[CuS2P] four-membered rings form a chair conformation.The Cu…Cu distance is 2.991(5) A.展开更多
The syntheses and structures of a novel series of polynuclear coinage metal cluster compounds are discussed. The most fascinating structural characteristic of the Au-Ag alloy clusters with Au_18Ag_19 and Au_18Ag_19 co...The syntheses and structures of a novel series of polynuclear coinage metal cluster compounds are discussed. The most fascinating structural characteristic of the Au-Ag alloy clusters with Au_18Ag_19 and Au_18Ag_19 cores and phosphine ligands, which were prepared by the reduction of mononuclear coinage metal complexes R3PAuX and R3PAgX with NaBH4 in organic solution, is their construction from 13-atom gold-centred icosahedral Au_7Ag_6 building blocks. The structures of the polynuclear coinage metal clusters with R2dtc ligands are variable with either unlimited linear chain or triangular M3 units.展开更多
The title complex, was pre-pared by using (NH4)2MoS4 as a starting material. X-ray crystal structural analysis ofthe complex gave the following parameters: In this complex, weak bond-ing of Cl- to three axial sulfur ...The title complex, was pre-pared by using (NH4)2MoS4 as a starting material. X-ray crystal structural analysis ofthe complex gave the following parameters: In this complex, weak bond-ing of Cl- to three axial sulfur atoms was found with average distance of 2. 717 TheCl atom locates at a special position and is bonded weakly by two cluster cations, indi-cating the oxidation number of + 1/2 for the cluster cation.展开更多
In this paper, single crystal EPR study of a new binuclear copper (Ⅱ) cluster compound-[Cu2(α-C(10) H7CH2CO2)4 (DMF)2]·[DMF]2·H2O](DMF= (CH3)2NCOH) at room temperature is reported. The lines of △Ms=±...In this paper, single crystal EPR study of a new binuclear copper (Ⅱ) cluster compound-[Cu2(α-C(10) H7CH2CO2)4 (DMF)2]·[DMF]2·H2O](DMF= (CH3)2NCOH) at room temperature is reported. The lines of △Ms=±1 allowing transition and △M=2 forbiding transition are shown in EPR spectra. The experimental data are consistent with the calculated results by the leastsquares fitting prograrn in three principal planes of g and D tensors. The spin Hamiltonian parameters are as follows: gx=2. 1482, gy=2. 0529 ,gz=2. 3905, D= 0. 348 cm￣(-1) and E =0. 01 cm-1. The diagrams of the energy levels have been obtained when the magnetic field is oriented to three principal axes. The polycrystal EPR spectra have been measured at room temperature and 77K, respectively.and the parameters of these spectra are given (g∥= 2. 094, g⊥= 2. 425, D= 0. 37 cm-1,E=0). The parameter of the isotropic magnetic exchange interaction J=-254cm-1 is determined, and that of the anisotropic magnetic exchange J1=-153 cm-1 is calculated. The average magnetic susceptibility of the polycrystal sample χ= 1. 39 ×10-6 (c. g. s) has been measured by Faraday powder method. Thus the average magnetic mornent μ=1. 43 B. M. can be calculated. It is shown that the exchange interactions between the metal ions of the binuclear copper(Ⅱ) cluster compound are confirmed antiferromagnetic In nature.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 localized molecular orbitals and energy levels for [Co_6 (μ_3-S)_8 (PH_3)_6]￣(n+)(n=0, 1) as model molecules of the electron-rich [Co_6 (μ_3-S)_8 (PPh_3)_6]￣(n+) (n=0,1) cluster compounds have been calculated ...The localized molecular orbitals and energy levels for [Co_6 (μ_3-S)_8 (PH_3)_6]￣(n+)(n=0, 1) as model molecules of the electron-rich [Co_6 (μ_3-S)_8 (PPh_3)_6]￣(n+) (n=0,1) cluster compounds have been calculated by using Edmiston-Ruedenberg energy localization scheme under the spin-unrestricted CNDO/2 approximation. It is shown that the cluster skeletons of these two isostructural molecules consist of the edge-localized two-centered two-electron (Co-S) bonds plus a pair of the skeleton electrons delocalized on the whole cluster core,leading an extra stability of the cluster core.The one-electron oxidation for the neutral molecule gives rise to a one-electron σ (Co-Co) bond.which further resonates among the three diagonal lines of the {Co_6} octahedron. The comparison between [Co_6 (μ_3-S)_8(PPh_3)_6] and [Co_6(μ_3-CO)_8(CO)_6]￣(4-) indicates that the latter possesses face-localized bridging-bonds which are further delocalized on the whole surface of the cluster octahedron by the back-donation bonds from the lone electron pairs on the Co atoms to the capping carbonyl CO ligands. The structural features of the series of the [Co6(μ_3-X)_8L_6]￣(n+)(X =S, Se; L=PPh_3,PEt_3, CO;n=0, 1) cluster compounds are briefly rationalized on the basis of the localization description as well.展开更多
This paper presents a versatile method for synthesizing electron-rich polynuclear transition metal clusters with chalcogen bridges and phosphine ligands.The reactions of transition metal complexes(R3P)2MX2(M=Co,Ni;R=P...This paper presents a versatile method for synthesizing electron-rich polynuclear transition metal clusters with chalcogen bridges and phosphine ligands.The reactions of transition metal complexes(R3P)2MX2(M=Co,Ni;R=Ph,Bu,Et;X=Cl,Br) with bridging reagents Na2Ex (E=S,Se;x=1.2) are described.The geometric and electronic structures of a series of polynuclear transition metal clusters with trianglar M3 units are also discussed.展开更多
The title compound (Mo 4XS 15 P 6O 12 C 24 H 30 ), α Mo 4XS 3( μ dtp) 3(dtp) 3 (X=0.6S+0.4O; dtp= -S 2P〔OEt〕 2), isolated as a prismatic black crystal, was prepared from ethanolic solution of Mo(CO) 6, MoCl 5 and ...The title compound (Mo 4XS 15 P 6O 12 C 24 H 30 ), α Mo 4XS 3( μ dtp) 3(dtp) 3 (X=0.6S+0.4O; dtp= -S 2P〔OEt〕 2), isolated as a prismatic black crystal, was prepared from ethanolic solution of Mo(CO) 6, MoCl 5 and P 2S 5. It crystallizes in triclinic system, space group P1 with a=14.031(4), b=13.372(2), c=16.270(8), α=92.15(2), β = 72.91(3), γ = 95.20(2)°, V = 2905.4(2) 3, Z = 2, D c = 1.82 g/cm 3, M r=1598.93, F(000)=1564.8, λ =0.71069 (Mo Kα ), μ =1.584 mm -1 . The final R=0.058, R w =0.057 for 5016 observed reflections with I≥3.0σ(I ). The structure analysis reveals that the title compound has a 〔Mo 4XS 3〕 core, belonging to the cubane type tetranuclear molybdenum clusters family, with one of its four μ 3 caps being statistically occupied by S and O. Three dtp ligands chelated three μ X capped Mo atoms as terminal ligands, while another three dtp bridged these three Mo atoms and the fourth one, forming an α type cluster compound.展开更多
A binuclear silver complex,Ag2Br2(PPh3)3·CH2Cl2,Mr=1247.4,monoclinic P21/c,a=16.306(3).b=18.444(3),c=18.807(3),β=111.21(2)°,V=5274.1(4).,Z=4,Dc=1.575 g/cm3,λ(MoKα)=0.71073,μ(MoKα)=24.7cm(-1),F(000)=2480...A binuclear silver complex,Ag2Br2(PPh3)3·CH2Cl2,Mr=1247.4,monoclinic P21/c,a=16.306(3).b=18.444(3),c=18.807(3),β=111.21(2)°,V=5274.1(4).,Z=4,Dc=1.575 g/cm3,λ(MoKα)=0.71073,μ(MoKα)=24.7cm(-1),F(000)=2480,final R=0.071,Rw=0.075 for 5007observed reflections.In the complex,Ag(1)and Ag(2)are bridged by two bromineatoms and coordinated in tetrahedral and trigonal geometries,respectively.展开更多
The heteroleptic dmit complex Et 4N 2 Ni 2(C 2S 4)(C 3S 5) 2 has been prepared by the reaction of NiCl 2·H 2O with Na 2dmit, NaSC 2H 4OH in the MeOH solution. The compound has been characteriz...The heteroleptic dmit complex Et 4N 2 Ni 2(C 2S 4)(C 3S 5) 2 has been prepared by the reaction of NiCl 2·H 2O with Na 2dmit, NaSC 2H 4OH in the MeOH solution. The compound has been characterized by X ray diffraction study, IR and UV Vis spectroscopy. Crystallographic data : space group: P2 1/n, a=11.843(2), b=11 079(1), c = 15.404(1) , β=110.33(1)°, V = 1895.1 3, Z=2, D c =1.62 g/cm 3 , μ =17.6 cm -1 , F (000)=956, R=0.052, R w =0.061. In the structure of the title complex, the tto (tto=tetrathioxalato) ligand in bridging form is chelated to two nickel atoms and dmit (dmit=1,3 dithiole 2 thione 4,5 dithiolate) ligands coordinated to nickel atoms.展开更多
The iR and Raman spectra were rrieasured for[Fe_2Cr(μ_3-O)-(glycine)_6 (H_2O)_3] (NO_3)_7. 3H2O in the range of 2000～90 cm￣-1. The assignment of the main skeleton vibrations was made in comparison with related comp...The iR and Raman spectra were rrieasured for[Fe_2Cr(μ_3-O)-(glycine)_6 (H_2O)_3] (NO_3)_7. 3H2O in the range of 2000～90 cm￣-1. The assignment of the main skeleton vibrations was made in comparison with related compounds. A simplified model as well as a simplified general valence force field was used in the normal coordinate analysis of the skeleton and a set of force constants has been obtained. The calculated frequencies agree well with the observed ones, with a mean deviation of 1.8% which confirms the assignn: ient of their vibrational spectra. On the basis of the data obtained some discussions were made.展开更多
The title compound was prepared by solid state reaction of LaCl_3/V inan evacuated silica tube where the silicon came from the reaction tube. The compoundcrystallizes in monoclinic space group C2/m with cell dimension...The title compound was prepared by solid state reaction of LaCl_3/V inan evacuated silica tube where the silicon came from the reaction tube. The compoundcrystallizes in monoclinic space group C2/m with cell dimensions of a=13. 482 (7), b=5. 604(3), c=11. 091(3) A, β=100. 44(3)°, V=824(1) A3, Mr= 1274. 66 , Dc=5. 14 g/cm3, F(000) = 1150, μ- 13. 20 mm-1 and Z=2; final R=0. 061, Rw=0. 054for 1037 observed reflections (Ⅰ>3σ(Ⅰ) ) . It is isostructural with quasi-ZD Pr_4V_5Si_4O_(22)compound with the Ⅴ-Ⅴ distances across the shared VO6 octahedral edges of 2. 802 Aand vanadium ions show mixed-valence(Ⅲ/Ⅳ) with an average value of+ 3. 2.展开更多
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(Et4N)[Mo3(μ3-O)(μ-Cl)3(μ-OAc)3Cl3], C14H29Cl6Mo3NO7, Mr = 823.92, triclinic, P1, a = 17. 508(4), b = 19. 602(3), c=8. 091(2)A, α=91. 25(2)°, β= 96. 56(2)°,γ= 83. 61(2)°, V = 2741(1)A3, Z = 4, Dc = 2.00g/cm3, MoKa (λ=0. 71069A), μ= 19. 44cm-1, F(000) = 1616, T = 23℃, final R = 0. 055, Rw = 0. 068 for 5728 unique intensity data (I≥3σ(I)).The molecule consists of cluster aniorn [Mo3(μ3-O) (μ-Cl)3(μ-OAc)3Cl3]- and cation (Et4N) + . There are two independent molecules in an asymmetric unit whose cluster anions A and B have the same configuration except for some bonding parameters. The cluster core may be described as an equilateral {Mo3} triangle with a capping O atom and three bridging Cl atoms below and above it respectively. In addition, each pair of Mo atoms is bridged by an acetate group and each Mo atom is further coordinated to a terminal chlorine atom. The three Mo - Mo bonds are 2. 587 (2), 2.587(2), 2. 582(2) A for cluster anion A and 2. 587(2), 2.595(2), 2.577 (2) A for cluster anion B. Altogether eight, d electrons occupy the {Mo3} cluster bonding orbitals.
文摘Magnetic susceptibility of a series of dinuclear Ⅴ(Ⅳ) . Co(Ⅱ) and Mn(Ⅲ) complexes has been measured in the temperature range of 1. 5 ～300K. The isotropic Heisenberg theory has been applied to study the temperature-dependent behaviour of the magnetic susceptibility of these complexes and a corresponding program for fitting the experimental results has been set up on a VAX 11/785 computer. Conclusions can be drawn that the three complexes studied are all anti-ferromagnetically coupled with coupling constants -4. 4 , -115. 2 , and - 8. 4 cm￣(-1) for Ⅴ(Ⅳ) . Co(Ⅱ) ,and Mn(Ⅲ) complexes, respectively.
文摘The title compound [Cu(dtp) PPh3]2 (dtp=S2,P(OEt)2) was prepared by heating the mononuclear compound Cu(dtp)(PPh3)2 in CH3CN solution.It crystallizes in the triclinic space group P1 with parameters a=9.71 6(5),b=11.026(5),c=12.475(4) A.α=78.16(3)°,β=102. 64(4), γ=114.34(4)°,V=1178(1)A 3,Z=1,Dc=1.44 g/cm3,MoKα(λ=0.71069 A) μ=12. 48cm-1,F(000)=528.Final R=0.041.Rω= 0. 052 for 3653 unique intensity data(I≥3σ(I)).The molecule of the title compound can be viewed as a centrosymmetric dimer with two[Cu(dtp)(PPh3)] units,which are bridged by two S atoms belonging to the dtp ligands.The exact planar[Cu2S2] core and two[CuS2P] four-membered rings form a chair conformation.The Cu…Cu distance is 2.991(5) A.
文摘The syntheses and structures of a novel series of polynuclear coinage metal cluster compounds are discussed. The most fascinating structural characteristic of the Au-Ag alloy clusters with Au_18Ag_19 and Au_18Ag_19 cores and phosphine ligands, which were prepared by the reduction of mononuclear coinage metal complexes R3PAuX and R3PAgX with NaBH4 in organic solution, is their construction from 13-atom gold-centred icosahedral Au_7Ag_6 building blocks. The structures of the polynuclear coinage metal clusters with R2dtc ligands are variable with either unlimited linear chain or triangular M3 units.
文摘The title complex, was pre-pared by using (NH4)2MoS4 as a starting material. X-ray crystal structural analysis ofthe complex gave the following parameters: In this complex, weak bond-ing of Cl- to three axial sulfur atoms was found with average distance of 2. 717 TheCl atom locates at a special position and is bonded weakly by two cluster cations, indi-cating the oxidation number of + 1/2 for the cluster cation.
文摘In this paper, single crystal EPR study of a new binuclear copper (Ⅱ) cluster compound-[Cu2(α-C(10) H7CH2CO2)4 (DMF)2]·[DMF]2·H2O](DMF= (CH3)2NCOH) at room temperature is reported. The lines of △Ms=±1 allowing transition and △M=2 forbiding transition are shown in EPR spectra. The experimental data are consistent with the calculated results by the leastsquares fitting prograrn in three principal planes of g and D tensors. The spin Hamiltonian parameters are as follows: gx=2. 1482, gy=2. 0529 ,gz=2. 3905, D= 0. 348 cm￣(-1) and E =0. 01 cm-1. The diagrams of the energy levels have been obtained when the magnetic field is oriented to three principal axes. The polycrystal EPR spectra have been measured at room temperature and 77K, respectively.and the parameters of these spectra are given (g∥= 2. 094, g⊥= 2. 425, D= 0. 37 cm-1,E=0). The parameter of the isotropic magnetic exchange interaction J=-254cm-1 is determined, and that of the anisotropic magnetic exchange J1=-153 cm-1 is calculated. The average magnetic susceptibility of the polycrystal sample χ= 1. 39 ×10-6 (c. g. s) has been measured by Faraday powder method. Thus the average magnetic mornent μ=1. 43 B. M. can be calculated. It is shown that the exchange interactions between the metal ions of the binuclear copper(Ⅱ) cluster compound are confirmed antiferromagnetic In nature.
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 localized molecular orbitals and energy levels for [Co_6 (μ_3-S)_8 (PH_3)_6]￣(n+)(n=0, 1) as model molecules of the electron-rich [Co_6 (μ_3-S)_8 (PPh_3)_6]￣(n+) (n=0,1) cluster compounds have been calculated by using Edmiston-Ruedenberg energy localization scheme under the spin-unrestricted CNDO/2 approximation. It is shown that the cluster skeletons of these two isostructural molecules consist of the edge-localized two-centered two-electron (Co-S) bonds plus a pair of the skeleton electrons delocalized on the whole cluster core,leading an extra stability of the cluster core.The one-electron oxidation for the neutral molecule gives rise to a one-electron σ (Co-Co) bond.which further resonates among the three diagonal lines of the {Co_6} octahedron. The comparison between [Co_6 (μ_3-S)_8(PPh_3)_6] and [Co_6(μ_3-CO)_8(CO)_6]￣(4-) indicates that the latter possesses face-localized bridging-bonds which are further delocalized on the whole surface of the cluster octahedron by the back-donation bonds from the lone electron pairs on the Co atoms to the capping carbonyl CO ligands. The structural features of the series of the [Co6(μ_3-X)_8L_6]￣(n+)(X =S, Se; L=PPh_3,PEt_3, CO;n=0, 1) cluster compounds are briefly rationalized on the basis of the localization description as well.
文摘This paper presents a versatile method for synthesizing electron-rich polynuclear transition metal clusters with chalcogen bridges and phosphine ligands.The reactions of transition metal complexes(R3P)2MX2(M=Co,Ni;R=Ph,Bu,Et;X=Cl,Br) with bridging reagents Na2Ex (E=S,Se;x=1.2) are described.The geometric and electronic structures of a series of polynuclear transition metal clusters with trianglar M3 units are also discussed.
文摘The title compound (Mo 4XS 15 P 6O 12 C 24 H 30 ), α Mo 4XS 3( μ dtp) 3(dtp) 3 (X=0.6S+0.4O; dtp= -S 2P〔OEt〕 2), isolated as a prismatic black crystal, was prepared from ethanolic solution of Mo(CO) 6, MoCl 5 and P 2S 5. It crystallizes in triclinic system, space group P1 with a=14.031(4), b=13.372(2), c=16.270(8), α=92.15(2), β = 72.91(3), γ = 95.20(2)°, V = 2905.4(2) 3, Z = 2, D c = 1.82 g/cm 3, M r=1598.93, F(000)=1564.8, λ =0.71069 (Mo Kα ), μ =1.584 mm -1 . The final R=0.058, R w =0.057 for 5016 observed reflections with I≥3.0σ(I ). The structure analysis reveals that the title compound has a 〔Mo 4XS 3〕 core, belonging to the cubane type tetranuclear molybdenum clusters family, with one of its four μ 3 caps being statistically occupied by S and O. Three dtp ligands chelated three μ X capped Mo atoms as terminal ligands, while another three dtp bridged these three Mo atoms and the fourth one, forming an α type cluster compound.
文摘A binuclear silver complex,Ag2Br2(PPh3)3·CH2Cl2,Mr=1247.4,monoclinic P21/c,a=16.306(3).b=18.444(3),c=18.807(3),β=111.21(2)°,V=5274.1(4).,Z=4,Dc=1.575 g/cm3,λ(MoKα)=0.71073,μ(MoKα)=24.7cm(-1),F(000)=2480,final R=0.071,Rw=0.075 for 5007observed reflections.In the complex,Ag(1)and Ag(2)are bridged by two bromineatoms and coordinated in tetrahedral and trigonal geometries,respectively.
文摘The heteroleptic dmit complex Et 4N 2 Ni 2(C 2S 4)(C 3S 5) 2 has been prepared by the reaction of NiCl 2·H 2O with Na 2dmit, NaSC 2H 4OH in the MeOH solution. The compound has been characterized by X ray diffraction study, IR and UV Vis spectroscopy. Crystallographic data : space group: P2 1/n, a=11.843(2), b=11 079(1), c = 15.404(1) , β=110.33(1)°, V = 1895.1 3, Z=2, D c =1.62 g/cm 3 , μ =17.6 cm -1 , F (000)=956, R=0.052, R w =0.061. In the structure of the title complex, the tto (tto=tetrathioxalato) ligand in bridging form is chelated to two nickel atoms and dmit (dmit=1,3 dithiole 2 thione 4,5 dithiolate) ligands coordinated to nickel atoms.
文摘The iR and Raman spectra were rrieasured for[Fe_2Cr(μ_3-O)-(glycine)_6 (H_2O)_3] (NO_3)_7. 3H2O in the range of 2000～90 cm￣-1. The assignment of the main skeleton vibrations was made in comparison with related compounds. A simplified model as well as a simplified general valence force field was used in the normal coordinate analysis of the skeleton and a set of force constants has been obtained. The calculated frequencies agree well with the observed ones, with a mean deviation of 1.8% which confirms the assignn: ient of their vibrational spectra. On the basis of the data obtained some discussions were made.
文摘The title compound was prepared by solid state reaction of LaCl_3/V inan evacuated silica tube where the silicon came from the reaction tube. The compoundcrystallizes in monoclinic space group C2/m with cell dimensions of a=13. 482 (7), b=5. 604(3), c=11. 091(3) A, β=100. 44(3)°, V=824(1) A3, Mr= 1274. 66 , Dc=5. 14 g/cm3, F(000) = 1150, μ- 13. 20 mm-1 and Z=2; final R=0. 061, Rw=0. 054for 1037 observed reflections (Ⅰ>3σ(Ⅰ) ) . It is isostructural with quasi-ZD Pr_4V_5Si_4O_(22)compound with the Ⅴ-Ⅴ distances across the shared VO6 octahedral edges of 2. 802 Aand vanadium ions show mixed-valence(Ⅲ/Ⅳ) with an average value of+ 3. 2.
