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1.
New synthesis procedures are described to tetranuclear manganese carboxylate complexes containing the [Mn(4)O(2)](8+) or [Mn(4)O(3)X](6+) (X(-) = MeCO(2)(-), F(-), Cl(-), Br(-), NO(3)(-)) core. These involve acidolysis reactions of [Mn(4)O(3)(O(2)CMe)(4)(dbm)(3)] (1; dbm is the anion of dibenzoylmethane) or [Mn(4)O(2)(O(2)CEt)(6)(dbm)(2)] (8) with HX (X(-) = F(-), Cl(-), Br(-), NO(3)(-)); high-yield routes to 1 and 8 are also described. The X(-) = NO(3)(-) complexes [Mn(4)O(3)(NO(3))(O(2)CR)(3)(R'(2)dbm)(3)] (R = Me, R' = H (6); R = Me, R' = Et (7); R = Et, R' = H (12)) represent the first synthesis of the [Mn(4)O(3)(NO(3))](6+) core, which contains an unusual eta(1):mu(3)-NO(3)(-) group. Treatment of known [Mn(4)O(2)(O(2)CEt)(7)(bpy)(2)](ClO(4)) with HNO(3) gives [Mn(4)O(2)(NO(3))(O(2)CEt)(6)(bpy)(2)](ClO(4)) (15) containing a eta(1):eta(1):mu-NO(3)(-) group bridging the two body Mn(III) ions of the [Mn(4)O(2)](8+) butterfly core. Complex 7 x 4CH(2)Cl(2) crystallizes in space group P2(1)2(1)2(1) with (at -168 degrees C) a = 21.110(3) A, b = 22.183(3) A, c = 15.958(2) A, Z = 4, and V = 7472.4(3) A(3). Complex 15 x (3)/(2)CH(2)Cl(2) crystallizes in space group P2(1)/c with (at -165 degrees C) a = 26.025(4) A, b = 13.488(2) A, c = 32.102(6) A, beta = 97.27(1) degrees, Z = 8, and V = 11178(5) A(3). Complex 7 contains a [Mn(4)(mu(3)-O)(3)(mu(3)-NO(3))](6+) core (3Mn(III), Mn(IV)) as seen for previous [Mn(4)O(3)X](6+) complexes. Complex 15 contains a butterfly [Mn(4)(mu(3)-O)(2)](8+) core. (1)H NMR spectra have been recorded for all complexes reported in this work and the various resonances assigned. All complexes retain their structural integrity on dissolution in chloroform and dichloromethane. Magnetic susceptibility (chi(M)) data were collected on 12 in the 5-300 K range in a 10.0 kG (1 T) field. Fitting of the data to the theoretical chi(M) vs T expression appropriate for a [Mn(4)O(3)X](6+) complex of C(3)(v)() symmetry gave J(34) = -23.9 cm(-)(1), J(33) = 4.9 cm(-)(1), and g = 1.98, where J(34) and J(33) refer to the Mn(III)Mn(IV) and Mn(III)Mn(III) pairwise exchange interactions, respectively. The ground state of the molecule is S = 9/2, as found previously for other [Mn(4)O(3)X](6+) complexes. This was confirmed by magnetization data collected at various fields and temperatures. Fitting of the data gave S = 9/2, D = -0.45 cm(-1), and g = 1.96, where D is the axial zero-field splitting parameter.  相似文献   

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Bi(5)(GaCl(4))(3) sample has been synthesized through the oxidation of Bi metal by gallium chloride (GaCl(3)) salt. Powder X-ray diffraction as well as micro-Raman scattering results revealed that, in addition to crystalline Bi(5)(GaCl(4))(3) in the product, an amorphous phase containing [GaCl(4)](-) and [Ga(2)Cl(7)](-) units also exists. The thorough comparison of steady-state and time-resolved photoluminescent behaviors between the Bi(5)(GaCl(4))(3) product and Bi(5)(AlCl(4))(3) crystal leads us to conclude that Bi(5)(3+) is the dominant emitter in the product, which gives rise to the ultrabroad emission ranging from 1 to 2.7 μm. Detailed quantum chemistry calculation helps us assign the observed excitations to some electronic transitions of the Bi(5)(3+) polycation, especially at shorter wavelengths. It is believed that our work shown here is not only helpful to solve the confusions on the luminescent origin of bismuth in other material systems, but also serves to develop novel broadband tunable laser materials.  相似文献   

4.
A new μ3-O triiron(III) complex [Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2 (HOBZ = benzoic acid) has been synthesized, its structure has been determined and variable temperature magnetic susceptility has also been measured. In the molecule, three iron atoms formed an equilateral triangle with μ3-O in center. The fitting to the magnetic susceptibility showed that an intramolecular antiferromagnetic exchange interaction occurred between iron atoms with J=-25.51 cm?1, and a weaker intermolecular autiferromagnetic exchange interaction occurred with zJ' = ?2.30 cm?1.  相似文献   

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An Anionic Oxohydroxo Complex with Bismuth(III): Na6[Bi2O2(OH)6](OH)2 · 4H2O Colourless, plate‐like, air sensitive crystals of Na6[Bi2O2(OH)6](OH)2 · 4H2O are obtained by reaction of Bi2O3 or Bi(NO3)3 · 5H2O in conc. NaOH (58 wt %) at 200 °C followed by slow cooling to room temperature. The crystal structure (triclinic, P 1¯, a = 684.0(2), b = 759.8(2), c = 822.7(2) pm, α = 92.45(3)°, ß = 90.40(3)°, γ = 115.60(2)°, Z = 1, R1, wR2 (all data), 0, 042, 0, 076) contains dimeric, anionic complexes [Bi2O2(OH)6]4— with bismuth in an ψ1‐octahedral coordination of two oxo‐ and three hydroxo‐ligands. The thermal decomposition was investigated by DSC/TG or DTA/TG and high temperature X‐ray powder diffraction measurements. In the final of three steps the decomposition product is Na3BiO3.  相似文献   

7.
New stereoregular cyclic polysilanols of the general formula [PhSi(O)OH]n (n = 6 and 12) have been selectively obtained in high yields by the reaction of cagelike oligophenylmetallasiloxanes with dilute solutions of hydrochloric acid at low temperatures. An alternative method was used to prepare cis-[PhSi(O)OH](4) from sodium phenylsiloxanolate, cis-[(Na(+))(4)[PhSi(O)O(-)](4)].(1-butanol)(x). All compounds were fully characterized by NMR and IR spectroscopy and molecular weight determinations. The structure of cis-[PhSi(O)OH](6) was confirmed by single-crystal X-ray analysis. Furthermore, a series of stereoregular cyclosiloxanes containing triorganylsiloxy groups at each silicon atom was prepared by the reactions of the cyclic polysilanols with triorganylchlorosilanes Me(3)SiCl, Me(2)ViSiCl, and Me(2)(CH(2)Cl)SiCl.  相似文献   

8.
The discrete heteropolyaurate [Au(III)(4)O(4)(Se(IV)O(3))(4)](4-) () represents only the second member of this class ever reported, and was synthesized via one-pot room temperature condensation in aqueous medium. was structurally characterized in the solid state and in solution by single-crystal XRD, TGA, FT-IR, (77)Se NMR, mass spectrometry and electrochemistry.  相似文献   

9.
测定了三核苯甲酸铁配合物[Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2(OBz-=苯甲酸根)的电子光谱,应用配体场理论和T-S图求得配体场参数10Dq=12457cm-1.用CNDO/2方法对其简化模型进行了计算。  相似文献   

10.
Iron was inserted into the known crystal structure of the bismuth phosphate oxide Bi6.67(PO4)4O4 to ascertain its location in the vacancies associated with the bismuth ion located at the origin of the unit cell. Single‐crystal X‐ray diffraction refinements converged to a model of composition Bi6(Bi0.32Fe0.68)(PO4)4O4 (hexabismuth iron tetraphosphate tetraoxide), in which Bi and Fe are displaced from the origin giving rise to a random distribution over the 2i sites instead of 1a, the origin of space group P. The isotropic displacement parameter for Bi/Fe has a reasonable value in this model. This structure establishes for the first time that Fe substitutes in the Bi‐deficient site in this series of materials and that Fe and Bi are disordered around the center of symmetry. These results enhance understanding of the crystal chemistry of these main group phosphates that are of interest in ion transport.  相似文献   

11.
In the present paper we report combined experimental and theoretical studies of the UV-vis-NIR spectra of the mineral compounds malachite, rosasite, and aurichalcite and of the precursor compounds for Cu/ZnO catalysts. For the copper species in the minerals the crystal field splitting and the vibronic coupling constants are estimated using the exchange charge model of the crystal field accounting for the exchange and covalence effects. On this basis the transitions responsible for the formation of the optical bands arising from the copper centers in minerals are determined and the profiles of the absorption bands corresponding to these centers are calculated. The profiles of the absorption bands calculated as a sum of bands of their respective Cu species are in quite good agreement with the experimental data. In agreement with crystal chemical considerations, the Zn ions were found to be preferentially located on the more regular, i.e., less distorted, octahedral sites in zincian malachite and rosasite, suggesting a high degree of metal ordering in these phases. This concept also applies for the mineral aurichalcite, but not for synthetic aurichalcite, which seems to exhibit a lower degree of metal ordering. The catalyst precursor was found to be a mixture of zincian malachite and a minor amount of aurichalcite. The best fit of the optical spectrum is obtained assuming a mixture of contributions from malachite (0% Zn) and rosasite (38% Zn of [Zn + Cu]), which is probably due to the intermediate Zn content of the precursor (30%).  相似文献   

12.
Yeh CY  Chiang YL  Lee GH  Peng SM 《Inorganic chemistry》2002,41(16):4096-4098
The one-electron oxidized linear pentanuclear nickel complexes [Ni(5)(tpda)(4)(H(2)O)(BF(4))](BF(4))(2) (1) and [Ni(5)(tpda)(4)(SO(3)CF(3))(2)](SO(3)CF(3)) (2) have been synthesized by reacting the neutral compound [Ni(5)(tpda)(4)Cl(2)] with the corresponding silver salts. These compounds have been characterized by various spectroscopic techniques. Compound 1 crystallizes in the monoclinic space group P2(1)/n with a = 15.3022(1) A, b = 31.0705(3) A, c = 15.8109(2) A, beta = 92.2425(4) degrees, V = 7511.49(13) A(3), Z = 4, and compound 2 crystallizes in the monoclinic space group C2/c with a = 42.1894(7) A, b = 17.0770(3) A, c = 21.2117(4) A, beta = 102.5688(8) degrees, V = 14916.1(5) A(3), Z = 8. X-ray structural studies reveal an unsymmetrical Ni(5) unit for both compounds 1 and 2. Compounds 1 and 2 show stronger Ni-Ni interactions as compared to those of the neutral compounds.  相似文献   

13.
Law GL  Wong KL  Zhou X  Wong WT  Tanner PA 《Inorganic chemistry》2005,44(12):4142-4144
New eight- and nine-coordinate luminescent europium(III) and terbium(III) complexes 1-4 with carbonyl group coordination have been prepared using the monodentate ligand (L) 2,4-diamino-6-hydroxy pyrimidine and characterized by X-ray and spectroscopic methods.  相似文献   

14.
The reactions of the singly deprotonated di-2-pyridylmethanediol ligand (dpmdH(-)) with copper(II) and bismuth(III) have been investigated. A new dinuclear bismuth(III) complex Bi(2)(dpmdH)(2)(O(2)CCF(3))(4)(THF)(2), 1, has been obtained by the reaction of BiPh(3) with di-2-pyridyl ketone in the presence of HO(2)CCF(3) in tetrahydrofuran (THF). The reaction of Cu(OCH(3))(2) with di-2-pyridyl ketone, H(2)O, and acetic acid in a 1:2:2:2 ratio yielded a mononuclear complex Cu[(2-Py)(2)CO(OH)](2)(HO(2)CCH(3))(2), 2, while the reaction of Cu(OAC)(2)(H(2)O) with di-2-pyridyl ketone and acetic acid in a 2:1:1 ratio yielded a tetranuclear complex Cu(4)[(2-Py)(2)CO(OH)](2)(O(2)CCH(3))(6)(H(2)O)(2), 3. The structures of these complexes were determined by single-crystal X-ray diffraction analyses. Three different bonding modes of the dpmdH(-) ligand were observed in compounds 1-3. In 2, the dpmdH(-) ligand functions as a tridentate chelate to the copper center and forms a hydrogen bond between the OH group and the noncoordinating HO(2)CCH(3) molecule. In 1 and 3, the dpmdH(-) ligand functions as a bridging ligand to two metal centers through the oxygen atom. The two pyridyl groups of the dpmdH(-) ligand are bound to one bismuth(III) center in 1, while in 3 they are bound two copper(II) centers, respectively. Compound 3 has an unusual one dimensional hydrogen bonded extended structure. The intramolecular magnetic interaction in 3 has been found to be dominated by ferromagnetism. Crystal data: 1, C(38)H(34)N(4)O(14)F(12)Bi(2), triclinic P&onemacr;, a = 11.764(3) ?, b = 11.949(3) ?, c = 9.737(1) ?, alpha =101.36(2) degrees, beta = 105.64(2) degrees, gamma = 63.79(2) degrees, Z = 1; 2, C(26)H(26)N(4)O(8)Cu/CH(2)Cl(2), monoclinic C2/c, a = 25.51(3) ?, b = 7.861(7) ?, c = 16.24(2) ?, beta = 113.08(9) degrees, Z = 4; 3, C(34)H(40)N(4)O(18)Cu(4)/CH(2)Cl(2), triclinic P&onemacr;, a = 10.494(2) ?, b = 13.885(2) ?, c = 7.900(4) ?, alpha =106.52(2) degrees, beta = 90.85(3) degrees, gamma = 94.12(1) degrees, Z = 1.  相似文献   

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A general synthetic approach to rationalize the solution preparative chemistry of oxovanadium phosphates containing organic species as structural directing agents is presented. Careful attention is payed to the hydrolysis and condensation processes involving the ionic species in solution, and a simple restatement of the partial charge model (PCM) has been used in order to organize the experimental results. The structure of a new V(IV)-Fe(III) bimetallic oxovanadium phosphate, [H(3)N(CH(2))(2)NH(3)](2)[H(3)N(CH(2))(2)NH(2)] [Fe(III)(H(2)O)(2)(V(IV)O)(8)(OH)(4)(HPO(4))(4)(PO(4))(4)].4H(2)O, has been determined by X-ray single crystal diffraction methods. This compound crystallizes in the monoclinic system, space group P2(1)/n and the cell dimensions are as follows: a = 14.383(3) ?, b = 10.150(2) ?, c = 18.355(4) ?, and beta = 90.39(3) degrees (Z = 2). The existence of a complex intercrossing channel system, including a very large channel of 18.4 ? of diameter (in which both water molecules and ethylenediamine species are located), is the more interesting feature of this structure. Thermal decomposition, including the dehydration/rehydration process, has been studied by thermal analysis and variable temperature X-ray powder diffraction techniques. A complementary SEM study of the different intermediate decomposition products is presented.  相似文献   

18.
Original and simple procedures for glassy carbon electrode modification with polyoxometalates (POMs), phosphotungstate [H7P8W48O184]33-, and Co(II)-containing silicotungstates [Co6(H2O)30{Co9Cl2(OH)3(H2O)9(beta-SiW8O31)3}]5- and [{Co3(B-beta-SiW9O33(OH))(B-beta-SiW8O29OH)2}2]22- give stable and very active surfaces for the hydrogen-evolution reaction (HER). For this purpose, the selected POMs fixed on Vulcan XC-72 were adsorbed on the electrode surface or were directly entrapped in polyvinylpyridine films on the electrode. Cyclic voltammetry and confocal microscopy results converge to indicate that the activation is related to the proton and electron reservoir-like behaviors of these molecular oxides and not to any electrode surface area increase. However, the Tafel parameters of the HER process, which are different from one POM to the next, are in the range of those of the best metallic electrodes.  相似文献   

19.
The magnetic property of μ3-oxotriiron(III) complex [Fe3O(OBz)6(CH3OH)3](NP3)-(CH3OH)2 (HOBz? benzoic acid) has been studied. We use isosceles triangle model and molecular field correction to fit the experimental magnetic susceptibility data. It shows that an intramolecular antiferromagnetic exchange interaction occurs with J = -31.27 cm?1, J'= -27.26 cm?1, and a weaker intermolecular antiferromagnetic exchange interaction occurs with zJ' = - 3.76 cm?1. We give the d5-d5-d5 energy level diagram of triiron(III) complex as a function of J'/J. From the diagram we can get the total spin ST of the complex as 1/2 in the ground state.  相似文献   

20.
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