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1.
1 INTRODUCTION The transition metal cluster complexes exhi- biting multistep redox processes have attracted more and more attention because of their potential applications in the areas of photonic and electronic devices[1~4]. The oxo-centered carboxyla…  相似文献   

2.
Abstract

[Cu(O2CCH3)2]2, 1, reacts with pyridine to form violet-blue Cu(O2CCH3)2(pyridine)3, 2, in > 90% yield. 2 crystallizes from pyridine with a distorted square-pyramidal geometry around copper with the monodentate acetate ligands located diagonally in the basal positions. 1 reacts with Bi(OCMe3)3 in THF to form blue Cu6(μ-O2CCH3)44-O2CCH3)2(μ-OCMe3)6, 3. 3 crystallizes from THF/hexanes with a hexagon of copper atoms linked by six doubly-bridging tert-butoxide ligands, four doubly-bridging bidentate acetates, and two quadruply-bridging bidentate acetate ligands.  相似文献   

3.
A novel Mg6 cluster molecule with the formula of Mg6( 3-OH)2( 3-Br)2(-Br)8(THF)8 (1) has been isolated in 38% yield from a reaction of the Grignard reagent, 2-naphthyl-Mg-Br with BBr3 in THF. The structure of 1, determined by a single-crystal X-ray diffraction analysis, contains two Mg3 triangles linked together by two bridging bromide ligands. Within each Mg3 triangle, one hydroxide and one bromide ligand function as triply bridging ligands capping both sides of the Mg3 triangle. The coordination geometry around each Mg(II) ion is approximately octahedral. NMR studies revealed that compound 1 is highly fluxional in solution.  相似文献   

4.
从均相Ziegler-Natta催化剂分离出有催化聚合活性的[Al~3Nd~6(μ-Cl~6(μ~2-Cl)~6(μ~2-Et)~9Et~4OPr)~2单晶,并用X光衍射法测得其晶体结构.结果表明,该单晶是由多核Nd-Al双金属配合物的二聚体组成,属三斜晶系;晶体的空间群为PI.晶胞参数α=1.5196(6),b=15.263(5),c=13.749(4)A;α=90.01(2),β=95.12(3),γ =82.65(3);V=3149.5A^3;Z=1.Nd原子的配位数是7,构型为单帽三棱柱.Nd原子由三重和二重氯桥连成分子骨架.本文对双金属配合物的催化活性中心也进行了讨论.  相似文献   

5.
6.
The synthesis and crystal structure of the first example for hybrid Sn-Mo tetranuclear cubane-like cluster compound containing S/O mixed triple capping atom [Mo3(SnBr3)(μ 3-O)(μ 3-S)3(dtp)3(py)3]·(CH2Cl2) (A) (dtp=S2P(OC2H5)2) are reported. The compound is prepared by the reaction of [Mo3(μ 3-O)(μ-S)3(dtp)4·(H2O)] with SnBr 3 ? . The molecular structure of the cluster can be described as a [Mo3OS3] core with the SnBr 3 ? fragment linked to {Mo3} triangle by three (μ 3-S). Three Mo-Mo bond lengths are 2.616(2), 2.620(2), 2.628(2) Å, respectively, and the molecule has approximately C3v symmetry. There is no bonding between Sn and Mo atoms, however, the addition of SnBr 3 ? may cause electron transfer from Sn2+ to [Mo3OS3] core to result in the shortening of Mo-Mo bond distances. The compound crystallizes in the monoclinic space group P21/n with refined lattice parameters ofa=13.012(4),b=22.877(6),c=18.585(6) Å,β=96.34(3)°,V=5498(3)Å3, andZ=4. Full matrix refinement converged with final agreement factor ofR=0.054,R w=0.064.  相似文献   

7.
8.
In this study we report about the aromaticity of the prototypical [(H(t)Ac)(3)(μ(2)-H)(6)], [(H(t)Th)(3)(μ(2)-H)(6)](+), and [(H(t)Pa)(3)(μ(2)-H)(6)] clusters via two magnetic criteria: nucleus-independent chemical shifts (NICS) and the magnetically induced current density. All-electron density functional theory calculations were carried out using the two-component zeroth-order regular approach and the four-component Dirac-Coulomb Hamiltonian, including scalar and spin-orbit relativistic effects. Four-component current density maps and the integration of induced ring-current susceptibilities clearly show that the clusters [(H(t)Ac)(3)(μ(2)-H)(6)] and [(H(t)Th)(3)(μ(2)-H)(6)](+) are non-aromatic whereas [(H(t)Pa)(3)(μ(2)-H)(6)] is anti-aromatic. However, for the thorium cluster we find a discrepancy between the current density plots and the classification through the NICS index. Our results also demonstrate the increasing influence of f orbitals, on bonding and magnetic properties, with increasing atomic number in these clusters. We think that the enhanced electron mobility in [(H(t)Pa)(3)(μ(2)-H)(6)] is due the significant 5f character of its valence shell. Also the participation of f orbitals in bonding is the reason why the protactinium cluster has the shortest bond lengths of the three clusters. This study provides another example showing that the magnetically induced current density approach can give more reliable results than the NICS index.  相似文献   

9.
The preparation and structural characterization of two trinuclear vanadium complexes, (V(3)(μ(3)-O)O(2))(μ(2)-O(2)P(CH(2)C(6)H(5))(2))(6)(H(2)O), 1, and (V(3)(μ(3)-O)O(2))(μ(2)-O(2)P(CH(2)C(6)H(5))(2))(6)(py), 2, are reported. In these nonclassical structures, the planar central core consists of the three vanadium atoms arranged in the form of an acute quasi-isosceles triangle with the central oxygen atom multiply bonded to the vanadium atom at the center of the vertex angle and weakly interacting with the two other vanadium atoms on the base sites, each of which contain one external multiply bonded oxygen atom. Reacting VO(acac)(2)in the presence of diphenylphosphinic acid affords (VO(O(2)PPh(2))(2))(∞), 3, while 2-hydroxyisophosphindoline-2-oxide at room temperature in CH(2)Cl(2) affords ((H(2)O)VO(O(2)Po-(CH(2))(2)C(6)H(4))(2))(∞), 4, and at 120 °C in EtOH yields (VO(O(2)P(o-(CH(2))(2)(C(6)H(4)))(∞), 5 on the basis of elemental analyses. The thermal and chemical stability of the complexes were assessed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements. The bond strengths of the vanadium atoms to the OH(2) ligand in 1 and to the NC(5)H(5) ligand in 2 were assessed at 10.7 and 42.0 kJ/mol respectively. Room temperature magnetic susceptibility measurements reveal magnetic moments for trinuclear 1 and 2 at 3.02(1) and 3.05(1) μ(B/mol), and also close to spin only values (1.73 μ(B)) values for 3, 4, and 5 at 1.77(2), 1.758(7), and 1.77(3) μ(B), respectively. Variable-temperature, solid-state magnetic susceptibility measurements were conducted on complex 2 in the temperature range of 2.0-298 K and at an applied field of 0.5 T. Magnetization measurements at 2 and 4 K confirmed a very weak magnetic interaction between the vanadyl centers.  相似文献   

10.
从均相Ziegler-Natta催化剂分离出有催化聚合活性的[Al_3Nd_6(μ_2-Cl)_6(μ_3-Cl)_6(μ_2-Et)_9Et_5OPr~i)_2单晶,并用X光衍射法测得其晶体结构.结果表明,该单晶是由多核Nd-Al双金属配合物的二聚体组成,属三斜晶系;晶体的空间群为PI.晶胞参数α=15.196(6),b=15.263(5),c=13.749(4)A;α=90.01(2),β=95.12(3),γ=82.65(3)°;V=3149.5A~3;Z=1.Nd原子的配位数是7,构型为单帽三棱柱.Nd原子由三重和二重氯桥连成分子骨架.本文对双金属配合物的催化活性中心也进行了讨论.  相似文献   

11.
<正> The title compound was prepared by reaction of Mo3(μ3-O) (μ-S)3-(dtp)4 (H2O) with C6H5COONa and pyridine. C27 H35 Mo3NO9P2S7, Mr = 1091.76, monoclinic, space group P21/c, a = 15. 057(5), b = 13. 052(5), c = 21. 662(6)(?), β=105.97(2)°, V = 4093(2) (?)3, Z = 4, Dc= 1. 77gcm-3, F(000) = 2176, μ(MoKα)=13.50cm-1, final R =0. 068 for 2835 observations. The molecular configuration is new and of approximate C, symmetry, and there are two C6H5COO bridging groups in the structure. The three Mo atoms form an isosceles triangle with three sides of 2. 567(3), 2. 576(3), and 2. 649(3)(?), where the two Mo-Mo bonds bridged by C6H5COO group are much shorter than that without. Something about the reactivity of Mo clusters is discussed.  相似文献   

12.
Reacting VO(acac)2 with six equivalents of dibenzylphosphinic acid in the presence of 4,4′-bipyridine or μ2-N1,N2-di(pyridin-4-yl)oxalamide leads to trimeric (V3(μ3-O)O2)(μ2-O2P(CH2C6H5)2)6(4,4′-bipyridine) or the hexamer [(V3(μ3-O)O2)(μ2-O2P(CH2C6H5)2)6]2(μ2-N1,N2-di(pyridin-4-yl)oxalamide). The complexes were characterized by spectroscopic (FTIR and 1H NMR spectroscopies), TGA, and by single crystal X-ray diffraction measurements. The structures consist of a planar central core where three vanadium ions are arranged in the form of a quasi-isosceles triangle and contain an interstitial O which is multiply bonded to one V and weakly interacting at different bond distances to the remaining two V ions.  相似文献   

13.
<正> [Mo3S4(μ-CH3COO)[S2P(OEt)2]3(py)]·(CH3COOCH2CH3) , Mr = 1197. 96,monoclinic,P21/n,a=13. 158(2),b=23. 153(5), c=16. 175(3) A,β = 112. 79(1)°,V=4543. 1(7)A3,Z=4, Dc= 1. 751g/cm-3,λ(MoKa) = 0. 71073A ,μ= 13. 799cm-1,F(000) = 2408. Final R=0. 067 for 4000 reflections. The structure consists of the neutral cluster molecule [Mo3S4(μ-OAc) (dtp)3(py)] (dtp = [S2P(OEt)2]) and the solvent ethyl acetate (AcOEt). The three Mo-Mo bond lengths in the title compound are 2. 691(2) ,2. 747(2) ,2. 762(2) A ,whereas the Mo-N bond length in Mo(3) position is 2. 36(2)A. The important bond lengths of these Mo clusters with (py) ring at the loose coordination site are listed for comparison.  相似文献   

14.
The synthesis and molecular structures of tris(pentamethylphenyl)aluminum, (C6Me5)3Al, (I), and the magnesium cluster [Mg6( 3-OH)2( 3-Br)2( 2-Br)8(OEt2)8] (II), are reported. Both compounds were isolated from the same system. The aluminum atom in (I) resides in an almost idealized trigonal planar environment. The dihedral angles of the pentamethylphenyl rings relative to the AlC3plane in (I) are 67.2, 62.4, and 61.2°. The neutral magnesium cluster, (II), is interesting in that contains six magnesium atoms each of which resides in octahedral environments.  相似文献   

15.
<正> Mr=963.9, monoclinic, P21/c, a=11.379(3), b=20.766(2), c=14.487(3) A,β=91.49(2)°, V=3518.9A3, Z=4, Dm=1.81, Dx=1.819 g·cm-3, MoKα radiation, λ=0.71073A, μ=18.167, F(000)=1916, T=293 K, R=0.040 for 3261 reflections. The structure consists of two sets of tetraethylammonium cations and trinuclear Mo cluster anions. The cluster skeleton is formed by three Mo atoms arranged in an isosceles triangle with a Cl and an O atoms as capping ligands.  相似文献   

16.
A new and facile method is presented for the synthesis of zirconocene carboxylate compounds, in which zirconocene dichloride (Cp2ZrCl2) is dissolved in 1 M aqueous HCl solution and the requisite ligand is dissolved in an organic solvent. Five such compounds [Cp2ZrCl(μ2-O′,O′′C-C6H5)] (1), [Cp2ZrCl(μ2-O′,O′′C-C6H3Cl2)] (2), [Cp2Zr(μ2-O′,O′′C-C6H3(OH)Cl)2] (3), [Cp2Zr(μ2-O′,O′′C-C6H3(OH)(NO2))2] (4), and [Cp2Zr(μ2-O′,O′′C-C6H(OH)Cl3)2] (5) have been obtained by this method. The effect of pH on the stability of Cp2ZrCl2 in 1 M HCl solution has been investigated by UV/vis spectrophotometry and 1H NMR spectrometry. The results showed that the aqueous Cp2ZrCl2 solutions became less stable with increasing pH, liberating cyclopentadiene. Accordingly, at higher pH (~7), two trinuclear zirconium monocyclopentadienyl compounds, [(CpZr)32-O′,O′′C-C6H3Cl2)33-OH)(μ2-OH)3](Cl2C6H3COO)2 (6) and [(CpZr)32-O′,O′′C-C6H4Cl)33-OH)(μ2-OH)3]Cl2·CH2Cl2 (7), were obtained. All compounds 17 have been characterized by FT-IR, 1H NMR spectra and elemental analysis. In all of the compounds, the aromatic acid acts as a bidentate ligand in coordinating to the zirconium; both chelating and bridging modes are observed. X-ray crystallographic studies on 1, 6, and 7 have revealed that the geometries at zirconium are distorted octahedral in 6 and 7, and distorted trigonal-bipyramidal in 1.  相似文献   

17.
Crystal structures of two new compounds containing trigonal tellurium-bridged cluster fragments [Mo3(3-Te)(2-Te2)3]4+ were investigated. Crystal data for K4.5{[Mo3(3-Te)(2-Te2)3(CN)6]I}I1.5·3H2O: space group , Z = 4, a = 13.280(1), c = 23.800(3) , V = 3635.0(6) 3, d calc = 3.432 g/cm3, R 1 = 0.0335, wR2 = 0.0912 for 1378 I hkl > 2 I from 3545 measured I hkl ; for Cs3{[Mo3(3-Te)(2-Te2)3(CN)6]I}·2H2O: space group P2 1 /n, Z = 2, a= 9.650(2) , b = 22.297(5), c = 27.446(7) , = 94.10(2)°, V = 5890(2) 3, d calc = 4.273 g/cm 3, R 1 = 0.0384, wR 2 = 0.0744 for 957 I hkl > 2 I from 3758 measured I hkl (Enraf-Nonius CAD-4 diffractometer, MoK , graphite monochromator). In both compounds, ionic pairs {[Mo3Te7(CN)6]I}3– with Teax...I distances of 3.358-3.676 are formed. In the potassium salt, the {[Mo3Te7(CN)6]I}3– anion pairs are linked by the additional TeeqI short contacts of 3.460 into two-dimensional corrugated layers perpendicular to the c axis of the unit cell. The structure of the cesium salt is ionic with interstitial H2O molecules and double-layer closest packing of anions.  相似文献   

18.
A new cluster compound {[Mo3(μ3-O)(μ-S)3(dtp)3(py)3][CdI(dtp)2]} (dtp=S2P(O-was obtained from the reaction of (Mo3OS3(dtp)4(H2O)] with a CdI2-Bu4NI mixture.The molecular structure is composed of a cluster cation [Mo3OS3(dtp)3(py)3]+ and the complex anion [CdI(dtp)2]-Crystal data:Triclinic,space group P1 with cell parameters a=1.4672(7),b=1.5356(5),c=1.6806(5) nm,α=74.59(3),β=67.89(4),7=78.86(3)°,V=3.364(2) nm3,and Z=2,least-squares refinement of 8941 reflections gives a final agreement factor of R=0.052,Rw=0.065.  相似文献   

19.
20.
The syntheses and structural properties of three dinuclear complexes [L(3)Co(μ(2)-O(2)P(Bn)(2))(3)CoL'][L"] [one ionic L(3) = py(3), L' = py, L" = ClO(4)(-) (1) and two molecular L(3) = py(3), L' = Cl (2) and L(3) = py, μ(2)-NO(3)(-), L' = py (3)] are reported. Complexes feature octahedral Co(II) sites bridged by three dibenzylphosphinate ligands to a tetrahedrally ligated Co(II) site, with the remaining coordination sites occupied by py, nitrato, and Cl ligands. The Co-Co distances are 4.248 ? at 291 K and 4.265 ? at 100 K for 1 and 4.278 and 4.0313(7) ? for 2 and 3, respectively at 100 K. A fit of the low-temperature magnetic susceptibility data was derived for complex 1 with g = 2.25, TIP = 700 × 10(-6) cm(3) mol (-1), λ = -173 cm(-1), κ = 0.93, ν = -3.9, Δ = 630 cm(-1), J = 0.15 cm(-1), and θ = -1.8 resulting in R(χ(M)) = 2.5 × 10(-5) and R(χ(M)T) = 5.8 × 10(-5).  相似文献   

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