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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 of f electrons. 相似文献
2.
The reaction of AgNO 3 with [(“Bu 4N 2 i-MNT)] 3 in CH 3CN produces a new silver cluster anion [Ag 4( i-MNT) 4] 4? , 3, a species having a tetrahedral arrangement of silver atoms bridged by four i-MNT ligands which has been isolated and characterized by X-ray crystallography as [Bu 4N] 2[(PPh 3) 2] 2 [Ag 4( i-MNT) 4], 4. The reaction of two or three equivalents of Ag(PPh 3) 2NO 3 with [BzEt 3N] 6[Ag 6( i-MNT) 6] in CH 3CN produces two new clusters, [BzEt 3N] 4[Ag 8( i-MNT) 6(PPh 3) 4], 6, and [BzEt 3N] 3[Ag 4( i-MNT) 6(PPh 3) 6], 7, having the common structural feature of an octahedral Ag 6S 12 core. The octanuclear Ag 8 cluster also can be synthesized from the reaction of 4 and PPh 3 in CH 2Ck 2 and compound 5 has been structurally characterized as [Bu 4N] 2[(PPh 3) 2N] 2[Ag 8( i-MNT) 6(PPh 3) 4]. The 31P{ 1H} NMR spectrum of 6 in CD 3CN 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, with a=18.668(3)A, b=36.793(4) A, c=17.836(3)A, Z=4, and V= 12250(3)A 3. Compound 5 crystallizes in the triclinic space group P1, with a=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, and V = 5164(2)A 3. Compound 6 crystallizes in the monoclinic space group C2/m, with a= 25.341(9)A, b= 25.289(9)A, c= 15.076(7)A, β= 107.19(5)°, Z=2, and V=9230(6)A 3. Compound 7 crystallizes in the monoclinic space group C2/c, with a=25.872(6)A, b=21.288(4) A, c=35,928(5), β=100.98(1)°, Z-4, and V=19426(6)A 3. 相似文献
3.
The complex ion [Fe(CN) 6SO 3] 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 SO 3 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(H 3O) 2[Mo(CN) 8]·0.5pz·3H 2O and (pzH) 2K(H 3O)[W(CN) 8]·H 2O 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 (D 4d), 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 K 3[Mo(CN) 8] · H 2O and MnCl 2 · 4H 2O in different reaction conditions have obtained three new bimetallic cyanide-bridged compounds, namely, {(tetrenH 2) 0.5[Mn(H 2O) 2][Mo V(CN) 8] · 2H 2O} n ( 1) (where, tetren is tetraethylenepentamine), {[Mn 2(H 2O) 4][Mo IV(CN) 8] · 3H 2O} n ( 2), and {[Mn 2(H 2O) 4][Mo IV(CN) 8] · 4H 2O} 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 Mn II centers in the extended structure adopt distorted octahedron geometry. For 1, each Mo V coordinated via four cyanide groups to four Mn II ions, and the other four cyanide groups are terminal, forming a two-dimensional framework. For 2, the Mo IV 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 [Mo IV(CN) 8] 4? building block is linked to Mn II ions through its eight CN ligands, and each Mn II 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 [Ph 3AmP] 2 + [Sb 2I 8 · 2DMSO] 2?, [Ph 3PrP] 2 + [Sb 2I 8 · C 4H 8O 2] 2?, and [(HOCH 2CH 2) 3NH] 4 + [Sb 4I 16] 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, -[SiW 9O 34] 10– with UO 2(NO 3) 2 leads to Na 14[Na 2(UO 2) 2(SiW 9O 34) 2]38H 2O ( 1, Monoclinic, P2 1/c, a=16.5719(8) Å, b=14.1689(7) Å, c=21.2528(10) Å, =111.6670(10)°, V=4786.6(4) Å 3, Z=2) which proves to be isostructural with the analogous derivative of [PW 9O 34] 9– reported previously. Solutions of 1 exhibit the 5-line W-NMR spectrum expected for the structure of C
i
point symmetry. The salt (NH 4) 17[(UO 2) 3(H 2O) 4As 3W 26O 94]16H 2O ( 2, Orthorhombic, Pnma, a=40.1747(2) Å, b=18.25840(10) Å, c=18.0817(2) Å, V=13263.4(2) Å 3, Z=4) was isolated in 64% yield from a reaction of UO 2(NO 3) 2 with B, -[AsW 9O 33] 9–. The structure of the anion in 2 has C
s
symmetry and contains one -AsW 9O 33 and two novel -AsW 8O 30 units linked by the UO 2+
2 groups; an additional WO 6 links the two AsW 8 fragments. Spectrophotometric titration of UCl 4 with the sodium salt of [As 4W 40O 140] 28– indicated the formation of a 4:1 U:As 4W 40 complex. During attempts to isolate a crystalline product from this reaction the uranium became oxidized and a guanidinium salt of [Na(UO 2) 3(OH)(H 2O) 6As 4W 40O 140(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 S 2 and adjacent sites of the lacunary As 4W 40 anion to be occupied by three UO 5 and one WO 5 polyhedra. A tetrameric assembly of -SiW 10 units linked by UO 2+
2 groups occurs in [{M(OH 2)} 4(UO 2) 4(OH) 2(SiW 10O 36) 4] 22– (lithium salt, M=Na, 4a, tetragonal, P4 2/nmc, a= b=26.5285(2) Å, c=15.0463(2) Å, V=10589.0(2) Å 3, 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) Å 3, 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.
The self-assembly of [M(CN) 8] 3− (M=Mo, W) anion and polyamine complexes of Cu II[Cu(tetren)] 2+ and [Cu(dien)(H 2O) 2] 2+ (tetren=tetraethylenepentamine, dien=diethylenetriamine) in acidic aqueous solution gives (tetrenH 5) 0.8{Cu II 4[W V(CN) 8] 4}·7.2H 2O 1, (tetrenH 5) 0.8{Cu II 4[Mo V(CN) 8] 4}·7.2H 2O 2, (dienH 3){Cu II 3[W V(CN) 8] 3}·4H 2O 3 and (dienH 3){Cu II 3[Mo V(CN) 8] 3}·4H 2O 4 2D coordination polymers. All compounds are structure-related: the crystal structures of isomorphous 1– 2 and 3– 4, respectively, consist of double-layered cyano-bridged {Cu II[W V(CN) 8] −} n square grid backbones and non-coordinated fully protonated polyamine countercations as well as H 2O 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.
Synthesis and characterisation of [tris(1,3-dithiole-2-thione-4,5-dithiolato)-stannate]2−, [Q]2[Sn(dmit)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(dmio)3] and [tris(1,3-dithiole-2-thione-4,5-selenolato)stannate]2−, [Q]2[Sn(dsit)3], complexes: Analysis of the structural variations of the [Sn(dmit)3]2− and [Sn(dmio)3]2− dianions
[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate] 2−, [Q] 2[Sn(C 3S 5) 3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate] 2−, [Q] 2[Sn(C 3S 4O) 3], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate] 2− [Q] 2[Sn(C 3S 3Se 2) 3], complexes, have been synthesised and characterised. Crystal structure determinations of [Q] 2[Sn(C 3S 5) 3] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe 4, NEt 4, and PPh 4) and [NEt 4] 2[Sn(C 3S 4O) 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 NMe 4, in chains for the somewhat larger cation, NEt 4 and is absent for the still larger, PPh 4 cation. 相似文献
11.
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 [Ti 8(C 2O 4) 8P 2W 18O 76(H 2O) 4] 18? ( 1) and the 32-tungsto-4-phosphate [Ti 6(C 2O 4) 4P 4W 32O 124] 20? ( 2) are formed upon reaction of the oxalato-titanium complex [TiO(C 2O 4) 2] 2? with the trilacunary Keggin precursor [ A-α-PW 9O 34] 9? and the hexalacunary Wells–Dawson precursor [H 2P 2W 12O 48] 12?, respectively. Polyanion 1 consists of two {PW 9} 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 {P 2W 16} 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 [Re 6S 8(CN) 6] 4−, [Re 5MoS 8(CN) 6] 5−, [Re 4Mo 2S 8(CN) 6] 5−, [Re 3Mo 3S 8(CN) 6] 5−, [Re 2Mo 4S 8(CN) 6] 5−, [ReMo 5S 8(CN) 6] 5− and [Mo 6S 8(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 [Re 3Mo 3S 8(CN) 6] 5−, [Re 2Mo 4S 8(CN) 6] 5− and [ReMo 5S 8(CN) 6] 5− clusters is similar to the calculated and observed gap of the superconducting PbMo 6S 8 Chevrel phases. The current calculations also indicates that the electronic similarities of the lowest excited states of
the semiconducting 24e [Re 5MoS 8(CN) 6] 5− and 23e [Re 4Mo 2S 8(CN) 6] 5− clusters with the strongly luminescent 24e [Re 6S 8(CN) 6] 4− cluster, suggest that these mixed metal clusters might be luminescent. 相似文献
16.
The mononuclear complex (NMe 4) 3[Re( 2-CS 3) 4] has been prepared by adding CS 2 to ReS –
4 in a mixture of MeOH and NH 3. During the reaction, Re VII is reduced to Re V, the measured diamagnetism ( X = –3.04 × 10 –4cm 3mol –1) of the complex showing that the two added electrons are coupled. (NMe 4) 3[Re( 2-CS 3) 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) Å 3. The reaction of CS 2 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 [Cu II(dipn)Ni II(CN) 4], and 3 [Cu(dipn)] 6[Co(CN) 6] 4?·?4H 2O (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][Cu 6] 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 Cu II and Cu II 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 K 5[MnMo 6Se 8(CN) 6] · 8H 2O ( 1), (Me 4N) 4[{Mn(H 2O) 2} 1.5Mo 6Se 8(CN) 6] · 4H 2O ( 2), and K 3[{Mn 2(H 2O) 4}Mo 6Se 8(CN) 6] · 7H 2O ( 3) have been synthesized by layering of a methanol solution of [Mn(salen)]CH 3COO (salen– N, N′-bis(salicylidene)ethylenediamine) on an aqueous solution of K 7[Mo 6Se 8(CN) 6] · 8H 2O. 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 [Mo 6Se 8(CN) 6] 7− cluster complexes are coordinated to Mn 2+ cations. Cavities in the frameworks are filled by additional cations and solvate water molecules. 相似文献
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