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1.
含有钒和钼的化合物在催化、抗病毒药物、功能材料等领域具有广阔的应用前景 [1~ 4 ] .近年来 ,钒取代的杂多化合物或金属 -氧簇的合成与表征已引起人们的广泛关注 ,许多新的化合物已被合成 ,如含五价钒的化合物 K7[Mo8V5O4 0 ]· 8H2 O和 Na3[VMo12 O4 0 ]· 1 9H2 O[5,6 ] ,含有混合价态钒的簇阴离子[( V V Mo10 ) VO4 0 ]6 - 和 [Mo8V V4 O4 0 ]8- 的化合物 [7,8] ,含双帽 Keggin 结构的簇阴离子[PMo6 VMo6 O4 0 ( V O) 2 ]5- 和 [PMo8V 4 V 2 O4 2 ]5- 的化合物 [9,10 ] 等 ,但所报道的含混合价态钒的 V- Mo化合物中含…  相似文献   

2.
合成了一种新的砷-钒-氧簇合物[Co(enMe)3]2[As8V14O42(H2O)]10H2O(enMe为1,2-丙二胺),用元素分析、IR和TGA-DTA等进行了表征,并用X射线衍射法测定了晶体结构。结果表明,该晶体属单斜晶系,C2/c空间群,晶胞参数a=28.990(7),b=15.540(6),c=22.77(1),b=131.24(4),Mr=2744.68,V=7714(7)3,Z=4,F(000)=5232,m(MoKa)=7.239mm-1,Dc=2.363g/cm3,R=0.069,Rw=0.073。结构测定表明,结构中簇阴离子[As8V14O42(H2O)]4-与配位阳离子[Co(enMe)3]2+之间靠静电作用相结合,同时通过氢键构成无限的三维骨架结构。  相似文献   

3.
合成了一种新的砷-钒-氧簇合物(H2en)6[As8V14O42(SO4)]28H2O(en为乙二胺),用元素分析、IR和TG-DTA等手段进行了表征,并用X射线衍射法测定了晶体结构。结果表明, 该晶体属单斜晶系,P21/c空间群,晶胞参数a = 20.9235(4),b = 11.9382(2),c = 43.5783(6) 牛琤 = 102.13,V = 10642.1(3) ?,Z = 4,Mr = 4678.01,Dc = 2.920 g/cm3,F(000) = 8944,m = 7.437 mm-1,R = 0.0735,wR = 0.1361。结构测定表明,结构中2个簇阴离子{[As8V14O42(SO4)]6-}与有机铵阳离子[H2en]2+之间靠静电作用相结合,同时与H2O通过氢键构成无限的三维骨架结构。  相似文献   

4.
金属 -氧簇合物在催化、医药和材料等方面的应用越来越成为无机化学研究的热点 [1~ 4 ] .在众多的金属 -氧簇合物中 ,只有几种双帽及四帽 Keggin结构被合成出来 [5~ 12 ] ,而含有四帽假 Keggin结构的钼 -钒 -氧簇合物尚未见报道 .我们用水热合成方法合成了第一个具有四帽假 Keggin结构“簇阴离子对”{Mo10 V6 O4 0 ( PO4 ) }2 的多金属氧簇 [Co( 2 ,2 - bipy) 3]4 [Mo10 V6 O4 0 ( PO4 ) ]2 · 4H2 O.该化合物是由四帽假Keggin结构“簇阴离子对”{Mo10 V6 O4 0 ( PO4 ) }2 和 4个配位阳离子 [Co( 2 ,2 - bipy) 3]2 +通过阴阳离…  相似文献   

5.
新型化合物[Ni(en)2V6O14]n的水热合成与晶体结构   总被引:1,自引:0,他引:1  
金属 -氧簇合物在催化吸附、医药临床、能量存储和材料科学等方面的应用越来越受到关注 [1~ 3 ] .钒 -氧簇合物的结构新颖 ,在材料领域中具有广泛的应用前景 .采用水热合成技术 ,以简单的无机、有机起始原料在相对低温下制备金属 -氧簇合物晶体是近年来刚刚兴起的研究工作 [4 ] ,并且已经合成出一维链状化合物 Cu(prn) 2 V2 O6[5]、层状结构 Ni(C10 H8N2 ) 2 V3 O8.5[6]及三维网状结构 (H2 en Me)[Ni(en) 2 V12 O2 8][7] .我们采用水热技术合成了由 { V V 2 O7} n 单元层与桥配体 [Ni(en) 2 ]2 +构建的三维无机 -有机化合物 [Ni(en…  相似文献   

6.
孙英华  杨美玲  郭庆芳  陈迪  姜小宇 《应用化学》2014,31(10):1210-1215
用水热方法合成了一个新型的钼钒多金属氧酸盐[PⅤMoⅥ7MoⅤVⅣ8O44][Ni(Phen)2OH]4·3H2O(1),用元素分析、红外光谱和X射线单晶衍射等技术手段对化合物的晶体结构进行了表征。结果表明,该化合物属于三斜晶系,P-1空间群,a=1.51300(11)nm,b=1.74813(15)nm,c=2.58896(18)nm,α=72.842(4)°,β=89.240(5)°,γ=72.627(5)°,V=6.2233(8)nm3,Z=1,R1=0.0962,wR2=0.2572。化合物是高还原态的四帽α-Keggin结构钼钒多金属氧簇,通过簇阴离子4个钒帽上的端氧分别支撑4个镍过渡金属配合物,形成一个中性的多金属氧酸盐。多金属氧簇上的端氧与结晶水分子之间的强烈氢键使化合物形成了三维超分子结构。  相似文献   

7.
以α-H5BW12O40·nH2O,Ce(NO3)3·6H2O和DMF为原料合成了组成为[Ce(DMF)4(H2O)][α-BW12O40]·H2O·(HDMA)2(HDMA:质子化的二甲胺;DMF:N,N-二甲基甲酰胺)的二维网状化合物,并对其进行了IR,UV光谱表征及TG-DTA研究.X射线单晶衍射结果表明,晶体属于单斜晶系,P21/n空间群,晶胞参数:a=1.1983(3),b=2.4216(5),c=1.9517(4)nm,β=92.91(3)°,Z=4,R1=0.07710,wR2=0.1416.结构测定结果表明,每一个[α-BW12O40]5?多阴离子通过端氧与三个[Ce(DMF)4(H2O)]3 单元相连;而每一个[Ce(DMF)4(H2O)]3 单元又通过Ce-Od-W桥与三个[α-BW12O40]5?多阴离子相连,以这种方式连接形成了二维网状结构.热分析结果表明,标题化合物失重分两步进行,阴离子骨架分解温度大约在560℃.电化学研究表明,pH=4~7时化合物存在三步氧化还原过程.  相似文献   

8.
本文采用水热技术合成了一种多钒氧酸盐[NH3(CH2)4NH3][H2pip]2[V10O28].6H2O(1,pip=哌嗪),并且通过元素分析、红外、热重、单晶X-射线衍射对化合物1进行了表征。化合物1为单斜晶系,空间群为P21/n,晶胞参数为a=1.229 85(10)nm,b=1.075 10(9)nm,c=1.496 71(12)nm,β=93.947 0(10)°,V=1.974 3(3)nm3,Z=2。晶体结构分析表明,化合物1是由[V10O28]6-阴离子簇、质子化的1,4-丁二胺和哌嗪阳离子以及结晶水构成。有机阳离子和结晶水通过O-H…O和N-H…O氢键相互作用将阴离子连接形成三维结构。  相似文献   

9.
在水热的条件下合成了1个多聚钒硼酸盐[Ni(en)2]6H2[(VO)12O6B18O42]15H2O,化学式为C24H128B18N24Ni6O75V12(Mr=3111.62),用单晶X射线衍射方法测定了它的结构,该晶体属三方晶系,R-3空间群,晶胞参数为a=13.942(2)?=96.476(2),V=2653.9(5)?,Z=1,Dc=1.947g/cm3,=21.55cm-1,F(000)=1574,2108个可观察衍射点(I>2(I)),最终结构精修到偏离因子R=0.0594,wR=0.1398,S=1.009。在该化合物的结构中,18员环的B18O42通过18个B(3-O)V键被2个V6O15簇夹在中间,6个[Ni(en)2]基团分别通过2个Ni(3-O)B与B18O42环相连。  相似文献   

10.
在水热的条件下合成了多钒硼酸盐(enH2)4Na4H3[(VO)12O6B18O42]8H2O, 化学式为C8H59B18N8Na4O68V12 (Mr=2253.45), 用单晶X射线衍射方法测定了它的结构, 该晶体属单斜晶系, P21/n空间群, 晶胞参数为a = 13.8989(4), b = 16.1954(5), c = 14.4520(4) ?β = 94.7490(5), V= 3241.95(16) ?, Z = 2, Dc = 2.308 g/cm3, ?= 1.819mm-1, F(000) = 2234, 4798个可观察衍射点(I > 2s(I)), 最终结构精修到偏离因子R = 0.0449, wR = 0.1163, S = 0.996。在该化合物的结构中, V12B18簇是由环状的B18O42通过18个B(μ3-O)V键被2个V6O18环夹在中间组成的, V12B18簇通过4个Na+与相邻的簇相连, 形成二维网状结构, 孔道尺寸为6.109×10.562 拧?  相似文献   

11.
Ferdov S  Reis MS  Lin Z  Ferreira RA 《Inorganic chemistry》2008,47(21):10062-10066
A new vanadium(III) phosphate, Na3V(OH)(HPO4)(PO4), has been synthesized by using mild hydrothermal conditions under autogeneous pressure. This material represents a very rare example of sodium vanadium(III) phosphate with a chain structure. The crystal structure has been determined by refinement of powder X-ray diffraction data, starting from the atomic coordinates of an isotypic compound, Na3Al(OH)(HPO4)(PO4), which was obtained under high temperature and high pressure. The phase crystallizes in monoclinic space group C2/m (No. 12) with lattice parameters a = 15.423(9) A, b = 7.280(0) A, c = 7.070(9) A, beta = 96.79(7) degrees, V = 788.3(9) A(3), and Z = 4. The structure consists of one-dimensional chains composed of corner-sharing VO5(OH) octahedra running along the b direction. They are decorated by isolated PO4 and HPO4 tetrahedra sharing two of their corners with the ones of the vanadium octahedra. The interconnection between the chains is assured by three crystallographically distinct Na(+) cations. Magnetic investigation confirms the 3+ oxidation state of the vanadium ions and reveals an antiferromagnetic arrangement between those ions through the chain.  相似文献   

12.
1 INTRODUCTION Current research interest is focused on the designof structures built up from octahedral and tetrahedralbuilding blocks[1]. During the wide investigations intransition-metal phosphates for many years, a num-ber of new mixed transition-metal phosphates havebeen reported[2]. A great number of manganese phos-phates were largely discovered as minerals[1]. On theother hand, many vanadium phosphates have alsobeen prepared recently partly because of their poten-tial applications …  相似文献   

13.
The preparation of oxovanadium(IV, V) coordination compounds with 2‐acetylpyridine‐2‐furanoylhydrazone (Hapf) is described. [VO(apf)(acac)] was prepared from oxovanadium(IV) diacetylacetonate [VO(acac)2] by reaction with Hapf in methanol or dichloromethane. The complex is paramagnetic and its EPR spectrum is consistent with an octahedral coordination for the vanadium(IV) atom. Voltammetry studies of [VO(apf)(acac)] indicate an irreversible oxidation, in agreement with the chemical behavior of the compound in solution. The vanadium(IV) complex undergoes slow oxidation in alcoholic solution, losing the acetylacetonate ligand to form [VO2(apf)] and [V2O2(μ‐O)2(apf)2]. The crystal structures of these last compounds were determined by X‐ray diffraction methods. [V2O2(μ‐O)2(apf)2] crystallizes monoclinic [P21/c, Z = 2, a = 817.400(10), b = 1650.90(3), c = 984.70(2) pm, β = 112.7190(10)°]. The crystal structure consists of dimeric units, in which two μ‐oxo ligands subtend asymmetric bridges between the vanadium atoms in a very distorted octahedral coordination. In the crystal of [VO2(apf)], orthorhombic [Pnma, Z = 4, a = 1630.000(10), b = 675.10(4), c = 1136.40(2) pm], the vanadium(V) atom is pentacoordinated.  相似文献   

14.
1INTRODUCTION Coordination chemistry of vanadium is of current interest since it is found to be beneficial to various biological systems[1,2].Pentavalent vanadium is also known to inhibit the functions of phosphate metabo-lizing enzymes by forming the analogue of trigonal-bipyramidal phosphorus(V)intermediate[3,4].In previous papers,some mono-and binuclear cis-dio-xovanadium(V)complexes with tridentate ligands were reported[5~8].On the other hand,hydrazones are important polydentate lig…  相似文献   

15.
The first quaternary vanadium niobium compounds containing triangular Nb(3) clusters corresponding to the general formula, AVNb(3)Cl(11) (A = K, Rb, Cs, Tl), have been prepared in sealed quartz tubes from stoichiometric amounts of ACl (A = K, Rb, Cs), or Tl metal, VCl(3), Nb powder, and NbCl(5) heated at 740 degrees C. The compounds crystallize in the orthorhombic space group Pnma (No. 62). The crystal structures of the Rb and Tl members were determined by single-crystal X-ray diffraction techniques. Crystal data: a = 12.771(3) A, b = 6.811(2) A, c = 17.183(3) A, V = 1494.6(1) A(3), and Z = 4 for A = Rb; and a = 12.698(5) A, b = 6.798(3) A, c = 17.145(10) A, V = 1480.0(13) A(3), and Z = 4 for A = Tl. The crystal structure of AVNb(3)Cl(11) consists of triangular Nb(3)Cl(13) clusters (Nb-Nb = 2.826 A) connected to each other via four outer ligands to form infinite chains along the b-axis. The chains are connected by vanadium atoms located in an octahedral environment to form puckered sheets. The A(+) counterions are located between adjacent sheets and coordinate to twelve chlorine ligands in anticubeoctahedral geometry. Electronic structure calculations show bonding orbitals similar to those in Nb(3)Cl(8). Magnetic susceptibility measurements show paramagnetic Curie Weiss behavior.  相似文献   

16.
Two different monoanionic O,N-chelating ligand systems, i.e., [OC6H2(CH2NMe2)-2-Me2-4,6]- (1) and [OCMe2([2]-Py)]- (2), have been applied in the synthesis of vanadium(V) complexes. The tertiary amine functionality in 1 caused reduction of the vanadium nucleus to the 4+ oxidation state with either [VOCl3], [V(=NR)Cl3], or [V(=NR)(NEt2)3] (R = Ph, (3a, 5a), R = p-Tol (3b, 5b)), and applying 1 as a reducing agent resulted in the synthesis of the vanadium(IV) complexes [VO(OC6H2(CH2NMe2)-2-Me2-4,6)2] (4) and [V(=NPh)(OC6H2(CH2NMe2)-2-Me2-4,6)2] (6). In the case of [V(=N-p-Tol)(NEt2)(OC6H2(CH2NMe2)-2-Me2-4,6)2] (7b), the reduction was sufficiently slow to allow its characterization by 1H NMR and variable-temperature studies showed it to be a five-coordinate species in solution. Although the reaction of 1 with [V(=N-p-Tol)(O-i-Pr)3] (9b) did not result in reduction of the vanadium nucleus, vanadium(V) compounds could not be isolated. Mixtures of the vanadium(V) (mono)phenolate, [V(=N-p-Tol)(O-i-Pr)2(OC6H2(CH2NMe2)-2-Me2-4,6)] (10), and the vanadium(V) (bis)phenolate, [V(=N-p-Tol)(O-i-Pr)(OC6H2(CH2NMe2)-2-Me2-4,6)2] (11), were obtained. With the pyridylalkoxide 2, no reduction was observed and the vanadium(V) compounds [VOCl2(OCMe2([2]-Py))] (12) and [V(=N-p-Tol)Cl2(OCMe2([2]-Py)] (13) were obtained. 51V NMR showed 7b and 12 to be five-coordinate in solution, whereas for 10, 11, and 13 a coordination number of 6 was found. Compounds 12 and 13 showed decreased activity compared to their nonchelated vanadium(V) analogues when applied as catalysts in ethene polymerization. Two polymorphic forms with a difference in the V-N-C angle of 12.5 degrees have been found for 6. Crystal data: 6.Et2O, triclinic, P1, a = 11.1557(6) A, b = 12.5744(12) A, c = 13.1051(14) A, alpha = 64.244(8) degrees, beta = 70.472(7) degrees, gamma = 87.950(6) degrees, V = 1547(3) A3, Z = 2; 6.C6H6, triclinic, P1, a = 8.6034(3) A, b = 13.3614(4) A, c = 15.1044(5) A, alpha = 98.182(3) degrees, beta = 105.618(2) degrees, gamma = 107.130(2) degrees, V = 1551.00(10) A3, Z = 2; 12, orthorhombic, Pbca, a = 11.8576(12) A, b = 12.6710(13) A, c = 14.722(2) A, V = 2211.9(4) A3, Z = 8.  相似文献   

17.
Vanadium interactions with low molecular mass binders in biological fluids entail the existence of vanadium species with variable chemical and biological properties. In the course of efforts to elucidate the chemistry related to such interactions, we have explored the oxidative chemistry of vanadium(III) with the physiologically relevant tricarboxylic citric acid. Aqueous reactions involving VCl(3) and anhydrous citric acid, at pH approximately 7, resulted in blue solutions. Investigation into the nature of the species arising in those solutions revealed, through UV/visible and EPR spectroscopies, oxidation of vanadium(III) to vanadium(IV). Further addition of H(2)O(2) resulted in the oxidation of vanadium(IV) to vanadium(V), and the isolation of a new vanadium(V)-citrate complex in the form of its potassium salt. Analogous reactions with K(4)[V(2)O(2)(C(6)H(4)O(7))(2)].6H(2)O and H(2)O(2) or V(2)O(5) and citrate at pH approximately 5.5 afforded the same material. Elemental analysis pointed to the molecular formulation K(4)[V(2)O(4)(C(6)H(5)O(7))(2)].5.6H(2)O (1). Complex 1 was further characterized by FT-IR and X-ray crystallography. 1 crystallizes in the triclinic space group P(-)1, with a = 11.093(4) A, b = 9.186(3) A, c = 15.503(5) A, alpha = 78.60(1) degrees, beta = 86.16(1) degrees, gamma = 69.87(1) degrees, V = 1454.0(8) A(3), and Z = 2. The X-ray structure of 1 reveals the presence of a dinuclear vanadium(V)-citrate complex containing a V(V)(2)O(2) core. The citrate ligands are triply deprotonated, and as such they bind to vanadium(V) ions, thus generating a distorted trigonal bipyramidal geometry. Binding occurs through the central alkoxide and carboxylate groups, with the remaining two terminal carboxylates being uncoordinated. One of those carboxylates is protonated and contributes to hydrogen bond formation with the deprotonated terminal carboxylate of an adjacent molecule. Therefore, an extended network of hydrogen-bonded V(V)(2)O(2)-core-containing dimers is created in the lattice of 1. pH-dependent transformations of 1 in aqueous media suggest its involvement in a web of vanadium(V)-citrate dinuclear species, consistent with past solution speciation studies investigating biologically relevant forms of vanadium.  相似文献   

18.
The reaction of VO(acac)2 with 2-hydroxyl-1-naphthaldehyde isonicotinyl hydrazone and amines (ethylenediamine or diethylenetriamine) in CH3OH yields crystals of novel vanadium compounds characterized by IR, NMR spectroscopic methods and X-ray single-crystal structure determination. Two different vanadium units exist in the crystal cell of [VO2(C17H11N3O2)][VO- (C4H13N3)(C6H5N3O)](C2H5OH) which crystallizes in the triclinic system, space group P1 with a = 8.0104(17), b = 13.898(3), c = 14.955(3)A, α = 89.103(4), β = 79.551(4), γ = 78.352(4)°, V = 1603.3(6)A^3, Mr = 723.54, Dc = 1.499 g/cm^3, Z = 2, λ(MoKα) = 0.71073 ]A,μ= 0.644 mm^-1, F(000) = 748, the final R = 0.0547 and wR = 0.0997 for 8920 observed reflections with I 〉 2σ(I). According to structure analysis, two different molecules are arranged in the lattice and the two vanadium atoms adopt octahedral and square pyramidal coordination geometries, respectively. The interactions between DNA and vanadium complexes have been investigated by UV-Vis absorption spectro- photometry.  相似文献   

19.
The hydrothermal syntheses of a family of new alkali-metal/ammonium vanadium(V) methylphosphonates, M(VO(2))(3)(PO(3)CH(3))(2) (M = K, NH(4), Rb, Tl), are described. The crystal structures of K(VO(2))(3)(PO(3)CH(3))(2) and NH(4)(VO(2))(3)(PO(3)CH(3))(2) have been determined from single-crystal X-ray data. Crystal data: K(VO(2))(3)(PO(3)CH(3))(2), M(r) = 475.93, trigonal, R32 (No. 155), a = 7.139(3) ?, c = 19.109(5) ?, Z = 3; NH(4)(VO(2))(3)(PO(3)CH(3))(2), M(r) = 454.87, trigonal, R32 (No. 155), a = 7.150(3) ?, c = 19.459(5) ?, Z = 3. These isostructural, noncentrosymmetric phases are built up from hexagonal tungsten oxide (HTO) like sheets of vertex-sharing VO(6) octahedra, capped on both sides of the V/O sheets by PCH(3) entities (as [PO(3)CH(3)](2-) methylphosphonate groups). In both phases, the vanadium octahedra display a distinctive two short + two intermediate + two long V-O bond distance distribution within the VO(6) unit. Interlayer potassium or ammonium cations provide charge balance for the anionic (VO(2))(3)(PO(3)CH(3))(2) sheets. Powder X-ray, TGA, IR, and Raman data for these phases are reported and discussed. The structures of K(VO(2))(3)(PO(3)CH(3))(2) and NH(4)(VO(2))(3)(PO(3)CH(3))(2) are compared and contrasted with related layered phases based on the HTO motif.  相似文献   

20.
The reaction of vanadium(III) acetylacetonate with HBF4 in acetonitrile yields [(CH3CN)5V-O-V(CH3CN)5][BF4]4, a material that serves as a convenient precursor to other [V-O-V]4+ species such as [(bipy)2(CH3CN)V-O-V(CH3CN)(bipy)2][BF4]4 (bipy=2,2'-bipyridine). Single-crystal X-ray diffraction shows that the V-O-V linkage of [(CH3CN)5V-O-V(CH3CN)5]4+ is linear. An Evans method measurement of the solution-phase magnetic susceptibility indicates strong ferromagnetic coupling between the vanadium centers. Magnetic susceptibility (chi) and magnetization (M(H)) data for a powdered sample and for a single crystal oriented with its V-O-V axis parallel to the applied field were measured over 1.8-300 K. The results suggest that the V(III) centers are ferromagnetically coupled with J approximately 72 K (approximately 50 cm(-1)) yielding a ground state with a total spin Stotal=2. Theoretical fit to the M(H) plot for the single crystal yielded g||=2.01+/-0.01 and the zero-field splitting parameter D=0.60+/-0.04 K (0.42+/-0.03 cm(-1)). EPR measurements at 34 and 101.6 GHz are consistent with the Stotal=2 ground state and yield g||=1.9825, g perpendicular=1.9725 and D=0.57+/-0.03 K.  相似文献   

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