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1.
Summary The question of the hybridization of the atomic orbitals of Mo in the Mo(CN)8 4– ion is examined, and it is shown that the dodecahedral structure can exist without the participation off electrons.  相似文献   

2.
The reaction of AgNO3 with [(“Bu4N2 i-MNT)]3 in CH3CN produces a new silver cluster anion [Ag4(i-MNT)4]4? ,3, a species having a tetrahedral arrangement of silver atoms bridged by fouri-MNT ligands which has been isolated and characterized by X-ray crystallography as [Bu4N]2[(PPh3)2]2 [Ag4(i-MNT)4],4. The reaction of two or three equivalents of Ag(PPh3)2NO3 with [BzEt3N]6[Ag6(i-MNT)6] in CH3CN produces two new clusters, [BzEt3N]4[Ag8(i-MNT)6(PPh3)4],6, and [BzEt3N]3[Ag4(i-MNT)6(PPh3)6], 7, having the common structural feature of an octahedral Ag6S12 core. The octanuclear Ag8 cluster also can be synthesized from the reaction of 4 and PPh3 in CH2Ck2 and compound 5 has been structurally characterized as [Bu4N]2[(PPh3)2N]2[Ag8(i-MNT)6(PPh3)4]. The31P{1H} NMR spectrum of 6 in CD3CN at ?43° shows two sets of two doublets. The corresponding chemical shift and coupling constant of each species is 9.32 ppm (354, 408.8 Hz) and 9.45 ppm (346.7, 401.7 Hz), respectively. Pertinent crystallographic data are as follows: Compound 4 crystallizes in the orthorhombic space group Cc2a, witha=18.668(3)A,b=36.793(4) A,c=17.836(3)A, Z=4, andV= 12250(3)A3. Compound 5 crystallizes in the triclinic space group P1, witha=16.506(3)A,b=17.280(3)A,c=19.144(4) A,x=98.485(14)°, β= 105.44(2)°.y=94.63(2),Z= 1, andV = 5164(2)A3. Compound6 crystallizes in the monoclinic space group C2/m, witha= 25.341(9)A,b= 25.289(9)A,c= 15.076(7)A, β= 107.19(5)°,Z=2, and V=9230(6)A3. Compound7 crystallizes in the monoclinic space group C2/c, witha=25.872(6)A,b=21.288(4) A,c=35,928(5), β=100.98(1)°,Z-4, andV=19426(6)A3.  相似文献   

3.
The complex ion [Fe(CN)6SO3]4− has been prepared in aqueous solution and as the zinc salt in the solid state. The electronic and IR spectra of the complex ion (I) have been recorded. MO calculations have been performed to understand the electronic structure of complex I. The electronic spectra of I and hexacyanoferrate(II) [HCF(II)] have been calculated and compared with the experimental results for I, HCF(II) and HCF(III). The experimental and theoretical results suggest that the oxidation state of Fe in I is + 3 and not +2 and the SO3 moiety is bonded to one of the nitrogen atoms of the cyano group.  相似文献   

4.
The interactions between [M(CN)8]4– (M = Mo or W) and pyrazine (pz) in the solid state and in aqueous solutions have been analysed. In strongly acidic solutions {pzH+, [M(CN)8]4–} ion pair formation is observed; the pyrazinium salts (pzH)2(H3O)2[Mo(CN)8]·0.5pz·3H2O and (pzH)2K(H3O)[W(CN)8]·H2O have been isolated. The X-ray crystal structure of the latter, and the spectroscopic properties of both, are described. The [W(CN)8]4– anion is approximately square antiprismatic (D4d), with different H-bond environments around the N atoms. The ligand-field photolysis of [M(CN)8]4– in the presence of pyrazine in neutral and alkaline solution results in the formation of tetracyanooxometallates(IV) in equilibrium with pentacyanooxometallates(IV) through the [M(CN)7(pz)]3– anions as intermediates. The formation of the [M(CN)6(pz)2]2– ion, postulated in the literature to be the final product of the alkaline photolysis, has definitively been excluded.  相似文献   

5.

The electrophoretic behavior of twenty anions has been studied on silica gel-G, titanium (IV) tungstate and silica gel-G- titanium (IV) tungstate admixture layers using 0.1 M solutions of oxalic acid, citric acid, tartaric acid, succinic acid and acetic acid as background electrolyte. The mechanism of migration is explained in terms of adsorption and the solubility of various sodium or potassium salts of the anions in water. Titanium (IV) tungstate behaves only as an adsorbent and not as an ion exchanger. Being a cation exchanger, there is no exchange phenomenon occurring with anions. The migration of halides increase linearly with an increase in the bare ion radii of these ions. Differential migration of the anions on silica gel-G layers led to binary, ternary and quaternary separations of similar anions such as F – Cl – Br – I, I – IO3 – IO4, BrO3 – IO3 and Fe(CN)63− – Fe(CN)64−. The two cyanoferrate ions are separated from industrial waste water and from fixer and bleach solutions. The migration of anions has also been found to be in accordance with their lyotropic numbers.

  相似文献   

6.
The reaction between K3[Mo(CN)8] · H2O and MnCl2 · 4H2O in different reaction conditions have obtained three new bimetallic cyanide-bridged compounds, namely, {(tetrenH2)0.5[Mn(H2O)2][MoV(CN)8] · 2H2O} n (1) (where, tetren is tetraethylenepentamine), {[Mn2(H2O)4][MoIV(CN)8] · 3H2O} n (2), and {[Mn2(H2O)4][MoIV(CN)8] · 4H2O} n (3). Compound 1 crystallizes in the orthorhombic system with space group Cmc21 and unit cell constants a = 7.8234(15), b = 26.013(5), c = 10.021(2) Å, β = 90°, and Z = 4. Compound 2 crystallizes in the monoclinic system with space group P21/n and unit cell constants a = 7.3329(11), b = 14.372(2), c = 18.070(3) Å, β = 90.869(2)°, and Z = 4. Compound 3 crystallizes in the tetragonal system with space group I4/m and unit cell constants a = b = 11.9371(8), c = 13.2930(18) Å, β = 90°, and Z = 4. X-ray single-crystal structures reveal that the Mo centers adopt a distorted square antiprism coordination environment for 1 and 3, while 2 closed to a bicapped trigonal prism. For these complexes, all the MnII centers in the extended structure adopt distorted octahedron geometry. For 1, each MoV coordinated via four cyanide groups to four MnII ions, and the other four cyanide groups are terminal, forming a two-dimensional framework. For 2, the MoIV center of structural unit coordinated via four cyanide groups to four Mn(1), and the other four cyanide groups coordinated to four Mn(2), forming a three-dimensional framework. For 3, each [MoIV(CN)8]4? building block is linked to MnII ions through its eight CN ligands, and each MnII center is connected to four Mo units forming a three-dimensional framework. In addition, magnetic studies of these complexes have also been presented.  相似文献   

7.
The reaction of equimolar amounts of triphenylamyl- and triphenylpropylphosphonium iodides and triethanolammonium iodide with antimony iodide in dimethyl sulfoxide, dioxane, or acetone gave complexes [Ph3AmP] 2 + [Sb2I8 · 2DMSO]2?, [Ph3PrP] 2 + [Sb2I8 · C4H8O2]2?, and [(HOCH2CH2)3NH] 4 + [Sb4I16]4?, the structure of which was established by X-ray diffraction analysis. The cations of all complexes have slightly distorted tetrahedral structure, and the antimony atoms in the anions are hexacoordinated. The crystals of the complexes have intra- and intermolecular contacts, which form the structure.  相似文献   

8.
Reaction of uranium salts with several lacunary polyoxotungstate anions yields four new heteropolyanion assemblies in which the uranium atoms occupy pentagonal bipyramidal coordination polyhedra. Treatment of A,-[SiW9O34]10– with UO2(NO3)2 leads to Na14[Na2(UO2)2(SiW9O34)2]38H2O (1, Monoclinic, P21/c, a=16.5719(8) Å, b=14.1689(7) Å, c=21.2528(10) Å, =111.6670(10)°, V=4786.6(4) Å3, Z=2) which proves to be isostructural with the analogous derivative of [PW9O34]9– reported previously. Solutions of 1 exhibit the 5-line W-NMR spectrum expected for the structure of C i point symmetry. The salt (NH4)17[(UO2)3(H2O)4As3W26O94]16H2O (2, Orthorhombic, Pnma, a=40.1747(2) Å, b=18.25840(10) Å, c=18.0817(2) Å, V=13263.4(2) Å3, Z=4) was isolated in 64% yield from a reaction of UO2(NO3)2 with B,-[AsW9O33]9–. The structure of the anion in 2 has C s symmetry and contains one -AsW9O33 and two novel -AsW8O30 units linked by the UO2+ 2 groups; an additional WO6 links the two AsW8 fragments. Spectrophotometric titration of UCl4 with the sodium salt of [As4W40O140]28– indicated the formation of a 4:1 U:As4W40 complex. During attempts to isolate a crystalline product from this reaction the uranium became oxidized and a guanidinium salt of [Na(UO2)3(OH)(H2O)6As4W40O140(WO)]18– (3, Orthorhombic, Fdd2, a=54.848(3) Å, b=80.809(4) Å, c=20.2874(2) Å, V=89919(7), Z=16) was isolated. The partially disordered structure of 3 shows the S2 and adjacent sites of the lacunary As4W40 anion to be occupied by three UO5 and one WO5 polyhedra. A tetrameric assembly of -SiW10 units linked by UO2+ 2 groups occurs in [{M(OH2)}4(UO2)4(OH)2(SiW10O36)4]22– (lithium salt, M=Na, 4a, tetragonal, P42/nmc, a=b=26.5285(2) Å, c=15.0463(2) Å, V=10589.0(2) Å3, Z=2; sodium-potassium salt, M=K, 4b, orthorhombic, Fddd, a=24.180(5) Å, b=31.696(6) Å, c=58.012(12) Å, V=44460(15) Å3, Z=8). Tungsten-183 NMR spectra show the slow transformation of the expected 5-line (1:1:1:1:1) spectrum of 4a to a new species giving a 6-line spectrum (2:2:2:1:2:1). The latter complex has not been successfully isolated.  相似文献   

9.
《Polyhedron》2003,22(14-17):2183-2190
The self-assembly of [M(CN)8]3− (M=Mo, W) anion and polyamine complexes of CuII[Cu(tetren)]2+ and [Cu(dien)(H2O)2]2+ (tetren=tetraethylenepentamine, dien=diethylenetriamine) in acidic aqueous solution gives (tetrenH5)0.8{CuII 4[WV(CN)8]4}·7.2H2O 1, (tetrenH5)0.8{CuII 4[MoV(CN)8]4}·7.2H2O 2, (dienH3){CuII 3[WV(CN)8]3}·4H2O 3 and (dienH3){CuII 3[MoV(CN)8]3}·4H2O 4 2D coordination polymers. All compounds are structure-related: the crystal structures of isomorphous 12 and 34, respectively, consist of double-layered cyano-bridged {CuII[WV(CN)8]}n square grid backbones and non-coordinated fully protonated polyamine countercations as well as H2O molecules located between the sheets. The magnetic measurements reveal long range ferromagnetic ordering with sharp phase transitions at TC in range 28–37 K and coercivity in range 30–225 Oe at liquid helium temperature, T=4.3 K.  相似文献   

10.
《Polyhedron》1999,18(26):3533-3544
[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S5)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S4O)3], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]2− [Q]2[Sn(C3S3Se2)3], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]2[Sn(C3S5)3] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe4, NEt4, and PPh4) and [NEt4]2[Sn(C3S4O)3] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe4, in chains for the somewhat larger cation, NEt4 and is absent for the still larger, PPh4 cation.  相似文献   

11.
K4[Fe(CN)6]-K3[Fe(CN)6]体系催化分光光度法测定痕量汞   总被引:1,自引:0,他引:1  
建立了一种测定痕量汞的催化分光光度新方法,它是基于汞能催化亚铁氰化钾分解生成Fe2 ,生成的Fe2 又与铁氰化钾反应生成兰色胶体溶液.方法的相对标准偏差≤5.3%,回收率为98.8%~104.8%之间,检出限为9.8×10-7 g/L;线性范围为0~0.050 μg/mL.  相似文献   

12.
[Mo_2FeS_8O_2][Et_4N]_3·CH_3CN晶体属三斜晶系,PI空间群.α=9.998(1)A,b=13.868(3)A,c=16.796(3)A,α=74.66(2)°,β=85.41(1)°,ν=72.21(1)°,Ζ=2.结构参数经块矩阵最小二乘法精修后,最后的偏离因子R=0.037,R_w=0.034.平均键长Mo—Fe为2.722A,Mo—S为2.358A,Fe—S为2.244A,Mo—O为1.697A.结果表明:标题化合物是一个结构新颖的原子簇化合物.它是由一个三价原子簇阴离子与三个一价的乙基季铵阳离子靠静电引力结合在一起,又溶剂合一个乙氰分子的原子簇化合物而形成.  相似文献   

13.
The oxalato-titanium(IV)-containing, dimeric 18-tungsto-2-phosphate [Ti8(C2O4)8P2W18O76(H2O)4]18? (1) and the 32-tungsto-4-phosphate [Ti6(C2O4)4P4W32O124]20? (2) are formed upon reaction of the oxalato-titanium complex [TiO(C2O4)2]2? with the trilacunary Keggin precursor [A-α-PW9O34]9? and the hexalacunary Wells–Dawson precursor [H2P2W12O48]12?, respectively. Polyanion 1 consists of two {PW9} units encapsulating eight titanium centers and connected to each other via two Ti–O–Ti bridges, and crystallizes as a mixed potassium-sodium-lithium salt in the triclinic space group $P{\bar{1}}$ . Polyanion 2 comprises two {P2W16} units containing each two titanium atoms, and the two half-units are connected via two titanium atoms decorated by two oxalate groups each, and crystallizes as a mixed potassium-lithium salt in the rhombohedral space group $R{\bar{3}}c$ . Polyanions 1 and 2 were characterized in the solid state by single-crystal XRD, FT-IR, and TGA, whereas polyanion 2 was also investigated by 31P and 183W NMR.  相似文献   

14.
Treatment of iodide-bridged dimer [NEt4] 4[Mo2O2S6Cu6I4Br2] 1 with 3, 5-bimethylpyridine or with K[(Ph2PS) 2N] in CH3CN afforded the tetranuclear cluster [MoOS3Cu3I(3,5-diMePy)4]·CH3CN 2 and dodecanuclear cluster (Et4N)4[Mo4Cu8O4S12{(Ph2PS)2N}4] 3. Monomeric 2 possess a nest-shaped skeleton.The structure of oligomeric 3 can be regarded as a tetramer of nest-shaped MoCu3OS3[(Ph2PS)aN]groups co-polymerized by sharing the limbic Cu atoms.  相似文献   

15.
Relativistic density functional calculations including scalar and spin-orbit effects via the ZORA approximation and including solvent effects were carried out on the [Re6S8(CN)6]4−, [Re5MoS8(CN)6]5−, [Re4Mo2S8(CN)6]5−, [Re3Mo3S8(CN)6]5−, [Re2Mo4S8(CN)6]5−, [ReMo5S8(CN)6]5− and [Mo6S8(CN)6]6− clusters. By increasing the replacement of each Re atom with Mo atoms we find that for x > 2 the HOMO–LUMO gap decreases significantly. The calculated gap of the [Re3Mo3S8(CN)6]5−, [Re2Mo4S8(CN)6]5− and [ReMo5S8(CN)6]5− clusters is similar to the calculated and observed gap of the superconducting PbMo6S8 Chevrel phases. The current calculations also indicates that the electronic similarities of the lowest excited states of the semiconducting 24e [Re5MoS8(CN)6]5− and 23e [Re4Mo2S8(CN)6]5− clusters with the strongly luminescent 24e [Re6S8(CN)6]4− cluster, suggest that these mixed metal clusters might be luminescent.  相似文献   

16.
The mononuclear complex (NMe4)3[Re(2-CS3)4] has been prepared by adding CS2 to ReS 4 in a mixture of MeOH and NH3. During the reaction, ReVII is reduced to ReV, the measured diamagnetism (X = –3.04 × 10–4cm3mol–1) of the complex showing that the two added electrons are coupled. (NMe4)3[Re(2-CS3)4] crystallizes in the space group Fddd, a = 11.985(4) Å, b = 23.001(11) Å, c = 47.463(19) Å, V = 13085(9) Å3. The reaction of CS2 results in the formation of trithiocarbonates bonded to the rhenium in a dodecahedral geometry.  相似文献   

17.
关于过渡金属乙腈配合物的合成和催化性能的研究在文献中已有很多报道。但是,含稀土元素的这类配合物的合成及催化性能的研究直到1986年才见报道。Thomas利用金属Eu和NOBF_4在乙腈中的反应制得了配合物[Eu(CH_3CN)_3(BF_4)_3]_x。本文报道了新乙睛稀土配合物[Sm(CH_3CN)_9]·(AlCl_4)_3·CH_3CN的合成及其晶体结构与分子结构。 (一) 实验 所有操作都在氩气保护下进行。无水SmCl_3用NH_4Cl法制得。AlCl_3经升华后使用。CH_3CN经P_2O_5干燥蒸馏。IR用Perkin-Elmer FTS-20红外光谱仪测定。  相似文献   

18.
Three new cyano-bridged complexes 1 [Ni(tn)2Ni(CN)4] (tn?=?1,3-diaminopropane), 2 [CuII(dipn)NiII(CN)4], and 3 [Cu(dipn)]6[Co(CN)6]4?·?4H2O (dipn?=?dipropylenetriamine) have been assembled by the templates [Ni(CN)4]2? and [Co(CN)6]3?. 1 consists of a one-dimensional linear chain–Ni(tn)2–NC–Ni(CN)2–CN–Ni(tn)2? in which the Ni(II) centers are linked by two CN groups. One 1-D zigzag chain of 2 is formed with–Ni(2)–C–N–Cu(1)–N–C–linkages. A 2D structure of 3 is formed by an alternate array of [Co(CN)6]3? and [Co][Cu6] units. For 1, there is an overall weak antiferromagnetic interaction between Ni(II) ions through the–NC–Ni–CN–bridges of the diamagnetic [Ni(CN)4]2? anions. 2 exhibits a weak antiferromagnetic exchange interaction between copper(II) ions mediated by [Ni(CN)4]2? diamagnetic bridges. Complex 3 exhibits a weak ferromagnetic interaction between nearest CuII and CuII atoms through–NC–Co–CN–bridges.  相似文献   

19.
The crystal structures of a new solvate of the ditopic receptor 1,3-calix[4]-bis-crown-6, Bis-C6, and of 1,3-calix[4]-bis-(benzo-crown-6), Bis-benzoC6, are reported. Bis-C6.3 CH3CN (1) crystallizes in the monoclinic space group P21/n, a = 14.388(3), b = 26.947(8), c = 14.707(4) Å, = 113.19(3)°, V = 5241(5) Å3, Z = 4. Refinement led to a final conventional R value of 0.092 for 2723 reflections. The structure of (1) differs from the previously reported structure of Bis-C6.4 CH3CN by the conformation of one crown either chain. Two acetonitrile molecules are in the close neighbourhood of the crown ether cavities. Bis-benzoC6.3 CH3CN (2) crystallizes in the monoclinic space group P21/c, a = 10.391(4), b = 17.264(11), c = 30.426(9) Å, = 94.62(3)°, V = 5440(7) Å3, Z = 4. Refinement led to a final conventional R value of 0.106 for 2965 reflections. Two acetonitrile molecules are located near the crown ether cavities, as in (1). One of the crown ether conformations is the same as in the binuclear caesium complex of Bis-benzoC6, supporting the hypothesis of a preorganization of this ligand towards the complexation of this ion; the second crown ether chain is partially disordered.  相似文献   

20.
Three novel coordination polymers K5[MnMo6Se8(CN)6] · 8H2O (1), (Me4N)4[{Mn(H2O)2}1.5Mo6Se8(CN)6] · 4H2O (2), and K3[{Mn2(H2O)4}Mo6Se8(CN)6] · 7H2O (3) have been synthesized by layering of a methanol solution of [Mn(salen)]CH3COO (salen–N,N′-bis(salicylidene)ethylenediamine) on an aqueous solution of K7[Mo6Se8(CN)6] · 8H2O. The compounds have been characterized by single-crystal X-ray diffraction analysis. All structures are based on negatively charged porous polymer frameworks where CN groups of [Mo6Se8(CN)6]7− cluster complexes are coordinated to Mn2+ cations. Cavities in the frameworks are filled by additional cations and solvate water molecules.  相似文献   

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