Cu[CC6H11O)2PS2]2配合物单晶的电子顺磁共振

本文报道了Cu[(C6H11O)2PS2]2配合物单晶在X波段室温下的电子顺磁共振研究. 电子顺磁共振谱显示出由^6^3Cu和^6^5Cu的磁性核引起的超精细结构以及由配体^3^1P的磁性核引起的配体超精细结构. 用非同轴的g张量和A张量系统的最小二乘拟合技术, 严格地计算了自旋Hamiltonian参数. g张量的主值表征, Cu^2^+处在由四个配体S形成的平行四方形的中心, 具有四角对称性, 但是由于配体中两个P的影响, 在CuS4平面上A张量的主值出现较大的各向异性. g张量和A张量有一个主轴是共轴的, 它们与CuS4平面垂直. 实验上观察到电子自旋与配体中^3^1P的相互作用是各向同性的, 并获得相应的配体超精细耦合常数A^p值.     

(NH4)2(15-crown-5)3[Cu(mnt)2]及(NH4)2(benzo-15-crown-5)4[Cu(mnt)2]·0.5H2O配合物单晶的结构和电子顺磁共振

用X射线衍射法测定了配合物(NH4)2(15-crown-5)3[Cu(mnt)2](1)及(NH4)2(benzo-15-crown-5)4[Cu(mnt)2]·0.5H2O(2)的晶体结构,两种配合物单晶分别由不同结构的冠醚超分子阳离子与[Cu(mnt)2]2-阴离子组成,配合物1呈三层夹心(triple-decker)双阳离子结构,配合物2的阳离子为三明治二聚物结构.两种配合物在X波段、室温下作了单晶电子顺磁共振(EPR)研究,配合物1没有检测到超精细结构,配合物2的EPR谱显示出Cu磁性核引起的超精细结构.用适于求非同轴的g和A张量的最小二乘法拟合技术严格计算了g张量和A张量的主值及其主轴的方向余弦,并计算了配合物2的Cu(Ⅱ)上的电子自旋密度分布,结果与用密度泛函理论(DFT)计算的值吻合.     

三核钼簇合物H[H2O]3[Mo3O(OAc)I3Cl6]的合成分子结构及红外光谱归属的研究

本文报道MoCl3.3H2O与乙酸作用生成三核钼簇合物H[H2O]3[Mo3O(OAc)3Cl6]的反应, 并用X射线单晶结构分析方法测定了簇合物的晶体结构, 结晶学参数. 结构分析结果表明该化合物阴离子为单氧帽等边三角形三核钼簇合阴离子, Mo-Mo平均距离2.569埃.对簇骼单元[Mo3O(μ-Cl)3Cl3]^2^+进行简正坐标分析. 从理论上对振动光谱谱带进行了归属. 10条IR谱带的观测和计算频率的平均偏差为1.15%. 本文讨论了特征谱带(包括金属键)的归属和力常数的合理性.     

多钼酸盐[4,4''-H2 bipy]2[β-Mo8O26]的水热合成和晶体结构

利用水热合成方法制备了化合物[4,4'-H2bipy]2[β-Mo8O26],用元素分析、X射线单晶衍射和电子顺磁共振对其结构进行了表征.结构解析表明标题化合物是由β型[Mo8O26]4-多阴离子与质子化的4,4'-联吡啶通过氢键作用形成的三维结构超分子化合物.     

双2:17钼磷系列稀土杂多蓝的合成和性质研究

首次合成和离析了八种以缺位型Dawson结构钼磷杂多阴离子为配体的稀土杂多蓝K17H2[Ln-(P2Mo17O61)2].nH2O和K17H4[Ln(P2Mo17O61)2].nH2O(Ln=La, Pr, Sm,Yb)。通过元素分析、电位滴定、红外光谱、紫外光谱、极谱、循环伏安、X射线光电子能谱、热重-差热分析和电子顺磁共振对杂多蓝进行了表征。实验结果表明,杂多阴离子还原为杂多蓝后, 性质发生了某些变化, 但结构基本不变, 配体P2Mo17O^1^061仍为α2型。     

Synthesis and Structure of One Novel Polyoxometalate Compound Connected via Cerium(Ⅲ) Cation with Three-dimensional Framework H2{[K(H2O)2]2[Ce(H2O)5]2(H2Mo1.16W10.84O42)}·8H2O

One novel polyoxometalate compound connected via trivalent cerium cation as bridge H2{[K(H2O)2]2[Ce(H2O)5]2(H2Mo1.16W10.84O42)}·8H2O 1 was designed and synthesized in aqueous solution. X-ray diffraction analysis reveals that the structure of 1 is a three-dimensional framework assembled from the arrangement of H2Mo1.16W10.84O42 (named paradodecmetalate-B) and Ce(H2O)53 containing two planes, which are constructed through the unification of H2Mo1.16W10.84O4210- and Ce(H2O)53 along the [100] and [001] directions. Crystal data H96Ce4K4Mo2.32O128W21.68, Mr = 7074.89, monoclinic, P21/n, a = 12.5037(17), b = 17.002(2), c = 12.7473(17) (A), β = 105.966(2)°, V = 2605.4(6) (A)3, Z = 1, Dc = 4.509 g/cm3, F(000) = 3132, μ = 26.098 mm(1, R = 0.0377 and wR = 0.0789 (I ＞ 2σ(I)).     

Cu[(C_6H_(11)O)_2PS_2]_2配合物单晶的电子顺磁共振

本文报道了 Cu[(C_6H_(11)O)_2PS_2]_2配合物单晶在 X 波段室温下的电子顺磁共振研究.电子顺磁共振谱显示出由~(63)Cu 和~(65)Cu 的磁性核引起的超精细结构以及由配体 ~(31)P 的磁性核引起的配体超精细结构.用非同轴的 g 张量和 A 张量系统的最小二乘拟合技术,严格地计算了自旋 Hamiltonian 参数.g 张量的主值表明,Cu~(2+)处在由四个配体 S 形成的平行四方形的中心,具有四角对称性,但是由于配体中两个 P 的影响,在 CuS_4平面上 A 张量的主值出现较大的各向异性.g 张量和 A 张量有一个主轴是共轴的,它们与 CuS_4平面垂直.实验上观察到电子自旋与配体中~(31)P 的相互作用是各向同性的,并获得相应的配体超精细耦合常数 A~p 值.     

Synthesis and Structure of One Novel Polyoxometalate Compound Connected via Cerium(Ⅲ) Cation with Three-dimensional Framework H2{[K(H2O)2]2[Ce(H2O)5]2(H2Mo1.16W10.84O42)}·8H2O

One novel polyoxometalate compound connected via trivalent cerium cation as bridge H2{[K(H2O)2]2[Ce(H2O)5]2(H2Mo1.16W10.84O42)}·8H2O 1 was designed and synthesized in aqueous solution. X-ray diffraction analysis reveals that the structure of 1 is a three-dimensional framework assembled from the arrangement of H2Mo1.16W10.84O42 (named paradodecmetalate-B) and Ce(H2O)53 containing two planes, which are constructed through the unification of H2Mo1.16W10.84O4210- and Ce(H2O)53 along the [100] and [001] directions. Crystal data: H96Ce4K4Mo2.32O128W21.68, Mr = 7074.89, monoclinic, P21/n, a = 12.5037(17), b = 17.002(2), c = 12.7473(17) (A), β = 105.966(2)°, V = 2605.4(6) (A)3, Z = 1, Dc = 4.509 g/cm3, F(000) = 3132, μ = 26.098 mm(1, R = 0.0377 and wR = 0.0789 (I ＞ 2σ(I)).     

Synthesis and Structural Characterization of a Polyoxomolybdate HNa7[Mo36O112(H2O)16]·47H2O

A new polyoxomolybdate complex HNa7[Mo36O112(H2O)16]·47H2O 1 has been prepared in the beaker solution and characterized by single-crystal X-ray diffraction and elemental analyses. Crystal data: H127Mo36Na7O175, Mr = 6542.79, monoclinic, C2/c, a = 40.891(6), b =17.900(3), c = 25.580(4) (A), β = 125.673(2)°, V = 15210(4)(A)3, Z = 4, Dc = 2.857 g/cm3, F(000) =12464, μ = 3.013 mm-1, R = 0.0633 and wR = 0.1654 (I＞ 2σ(Ⅰ)). With the bridging sodium cations,the [Mo36O112(H2O)16]8- units in compound 1 are linked to form a one-dimensional structure, on the basis of which a three-dimensional architecture is further constructed via other sodium cations and complicated hydrogen bonds.     

Synthesis, Crystal Structure, UV-vis and EPR Studies of（ NH3CH2CH2NH2 ） 2.5 [ Mo0.5^（V）W0.5^（VI）O2 （ OC6H4O ） 2]

Cis-dioxo-metal complex ( NH3CH2CH2NH2 ) 2.5 [ Mo0.5^(V)W0.5^(VI)O2 ( OC6H4O ) 2] 1 was obtained by the reaction of tetra-butyl ammonium hexamolybdotungstate with 1, 2-dihydroxybenzene in the mixed solvent of CH3OH, CH3CN and ethylenediamine,and characterized by X-ray diffraction, UV-vis and EPR analysis. Compared with its analogous complexes (NH3CH2CH2NH2)3[Mo^(V)O2(OC6H40)2] 2 and (NH3CH2CH2NH2)2[W^(VI)O2(OC6H4O)2] 3, the results show that tungsten(VI) is less active in redox than molybdenum (VI) and that the change of the valence induced by substitution of W(VI) for Mo(V) in EMO2(OC6H40)2]n- does not influence the coordination geometry of the complex anion in which the metal center exhibits distorted octahedral coordination with cis-dioxo catechol. The responses to EPR of complexes 1 and 2 are active but complex 3 is silent,and the UV-vis spectra exhibited by the three complexes are obvious different because of the different electronic configuration between the central Mo(V) and W(VI) ions in the complexes.It is noteworthy that complexes 1 and 2 have the similar EPR signal to flavoenzyme, suggesting that the three complexes have the same coordination geometry feature with the co-factor of flavoenzyme.     

Polyoxometalate-supported transition metal complexes and their charge complementarity: synthesis and characterization of [M(OH)6Mo6O18[Cu(Phen)(H2O)2]2][M(OH)6Mo6O18[Cu(Phen)(H2O)Cl]2].5H2O (M = Al(+, Cr3+)

Two Anderson-type heteropolyanion-supported copper phenanthroline complexes, [Al(OH)6Mo6O18[Cu(phen)(H2O)2]2]1+ (1c) and [Al(OH)6Mo6O18[Cu(phen)(H2O)Cl]2]1- (1a) complement their charges in one of the title compounds [Al(OH)6Mo6O18[Cu(phen)(H2O)2]2][Al(OH)6Mo6O18[Cu(phen)(H2O)Cl]2].5H2O [1c][1a].5 H2O 1. Similar charge complementarity exists in the chromium analogue, [Cr(OH)6Mo6O18[Cu(phen)(H2O)2]2][Cr(OH)6Mo6O18[Cu(phen)(H2O)Cl]2].5 H2O [2c][2a].5 H2O 2. The chloride coordination to copper centers of 1a and 2a makes the charge difference. In both compounds, the geometries around copper centers are distorted square pyramidal and those around aluminum/chromium centers are distorted octahedral. Three lattice waters, from the formation of intermolecular O-H.....O hydrogen bonds, have been shown to self-assemble into an "acyclic water trimer" in the crystals of both 1 and 2. The title compounds have been synthesized in a simple one pot aqueous wet-synthesis consisting of aluminum/chromium chloride, sodium molybdate, copper nitrate, phenanthroline, and hydrochloric acid, and characterized by elemental analyses, EDAX, IR, diffuse reflectance, EPR, TGA, and single-crystal X-ray diffraction. Both compounds crystallize in the triclinic space group P. Crystal data for 1: a = 10.7618(6), b = 15.0238(8), c = 15.6648(8) angstroms, alpha = 65.4570(10), beta = 83.4420(10), gamma = 71.3230(10), V = 2182.1(2) angstroms3. Crystal data for 2: a = 10.8867(5), b = 15.2504(7), c = 15.7022(7) angstroms, alpha = 64.9850(10), beta = 83.0430(10), gamma = 71.1570(10), V = 2235.47(18) angstroms3. In the electronic reflectance spectra, compounds 1 and 2 exhibit a broad d-d band at approximately 700 nm, which is a considerable shift with respect to the value of 650-660 nm for a square-pyramidal [Cu(phen)2L] complex, indicating the coordination of [M(OH)6Mo6O18]3- POM anions (as a ligand) to the monophenanthroline copper complexes to form POM-supported copper complexes 1c, 1a, 2c, and 2a. The ESR spectrum of compound 1 shows a typical axial signal for a Cu2+ (d9) system, and that of compound 2, containing both chromium(III) and copper(II) ions, may reveal a zero-field-splitting of the central Cr3+ ion of the Anderson anion, [Cr(OH)6Mo6O18]3-, with an intense peak for the Cu2+ ion.     

(H_2en)_2[Se_2Mo_5O_(21)]2H_2O的水热合成、晶体结构与光谱研究

在水热条件下, 以SeO2、V2O5、MoO3、K2CO3、en(乙二胺)作为起始原料, 得到了标题化合物(H2en)2[Se2Mo5O21]2H2O, 利用IR、UV、荧光光谱、单晶-X射线衍射等方法对其进行了表征。结构测定表明, 该化合物属于正交晶系, 空间群: P212121, 化学式: C4H24- Mo5N4O23Se2, 晶胞参数: a = 12.1386(7), b = 17.7118(8), c =11.7092(5) ? V = 2517.4(2) ?, Z = 4, Dc = 2.987 g/cm3, Mr = 1133.89, m = 5.419 mm-1, F(000) = 2144, 最终结构偏离因子R = 0.0285, wR = 0.0400, S = 0.904。该化合物由2个双质子化的en、2个H2O分子以及杂多阴离子[Se2Mo5O21]4-组成。其中,杂多阴离子由5个畸变的MoO6八面体以共边或共顶点形式连接构成一个平面骨架; 2个畸变的SeO3四面体和MoO6八面体以共顶点形式连接, 且位于平面的两侧;质子化的en位于4个[Se2Mo5O21]4-离子围成的四面体空位中, 与杂多阴离子和水分子通过氢键连接成无限三维结构。最后我们用B3LYP方法研究了阴离子簇的电子结构。     

4:2钼、钨过氧配合物的制备、结构及其氧化还原分解行为

本文作者曾在用过钨酸分解法制备钨酸的过程中发现, 溶液中W与O2^2^-之比始终为2:1, 这一事实说明溶液中有2:1金属过氧配合物形成, 2:1铂过氧络合物[Mo4O12(O2)2]^4^-文献上已有记载, 但类似的钨配合物尚未见报道。本文制备了这二种配合物, 对比它们的红外和Raman光谱, 并用循环伏安法, 恒电位电解法探讨它们的氧化还原分解体系。     

Experimental and theoretical investigations of the sulfite-based polyoxometalate cluster redox series: alpha- and beta-[Mo(18)O(54)(SO(3))(2)](4-/5-/6-)

The synthesis, isolation and structural characterization of the sulfite polyoxomolybdate clusters alpha-(D(3h))(C(20)H(44)N)(4){alpha-[Mo(18)O(54)(SO(3))(2)]}CH(3)CN and beta-(D(3d))(C(20)H(44)N)(4){beta-[Mo(18)O(54)(SO(3))(2)]}CH(3)CN is presented. Voltammetric studies in acetonitrile (0.1 M Hx(4)NClO(4), Hx(4)N=tetra-n-hexylammonium) reveal the presence of an extensive series of six one-electron reduction processes for both isomers. Under conditions of bulk electrolysis, the initial [Mo(18)O(54)(SO(3))(2)](4-/5-) and [Mo(18)O(54)(SO(3))(2)](5-/6-) processes produce stable [Mo(18)O(54)(SO(3))(2)](5-) and [Mo(18)O(54)(SO(3))(2)](6-) species, respectively, and the same reduced species may be produced by photochemical reduction. Spectroelectrochemical data imply that retention of structural form results upon reduction, so that both alpha and beta isomers are available at each of the 4-, 5-, and 6-redox levels. However, the alpha isomer is the thermodynamically favored species in both the one- and two-electron-reduced states, with beta-->alpha isomerization being detected in both cases on long time scales (days). EPR spectra also imply that increasing localization of the unpaired electron occurs over the alpha- and beta-[Mo(18)O(54)(SO(3))(2)](5-) frameworks as the temperature approaches 2 K where the EPR spectra show orthorhombic symmetry with different g and hyperfine values for the alpha and beta isomers. Theoretical studies support the observation that it is easier to reduce the alpha cluster than the beta form and also provide insight into the driving force for beta-->alpha isomerization in the reduced state. Data are compared with that obtained for the well studied alpha-[Mo(18)O(54)(SO(4))(2))](4-) sulfate cluster.     

Synthesis, crystal structure and properties of a new organic-inorganic hybrid Dawson-like polyoxotungstate [Co(2,2''-bpy)3]2[Co(2,2''-bpy)2Cl][Co(2,2''-bpy)2]H2-[SbW18O60]·4H2O

A new organic-inorganic hybrid polyoxometalate based on Dawson-like polyoxotungstate anion [SbW18O60]9-, formulated [Co(2,2'-bpy)3]2[Co(2,2'-bpy)2Cl][Co(2,2'-bpy)2]H2[SbW18O60]·4H2O (2,2'-bpy= 2,2(-bipyridine) has been synthesized from Sb2O3, Na2WO4, CoCl2, and 2,2'-bipyridine materials by hydrothermal method, and which was characterized by elemental analyses, IR, XPS, EPR, TG, and X-ray single crystal diffraction. Structure analysis shows that the polyoxoanion self-assembled under hydrothermal conditions consists of a Dawson-like polyoxotungstate cluster anion [SbW18O60]9- encapsulating a pyramidal {SbO3} group within the {W18} cluster cage. EPR spectra show that the high-spin octahedral CoⅡ and low-spin CoⅡ ions coexist in the title compound. Magnetic properties indicate that the compound is antiferromagnetic.     

Cations M2(O2CtBu)4+, where M = Mo and W, and MoW(O2CtBu)4+. Theoretical, spectroscopic, and structural investigations

With the aid of density function theory, the molecular and electronic structures of the molecules Mo2(O2CMe)4, MoW(O2CMe)4, and W2(O2CMe)4 and their single-electron oxidized radical cations have been determined; this includes calculated observables such as v(MM) and the delta --> delta* electronic transition energies. The calculated properties are compared with those for the corresponding pivalates, M2(O2CtBu)4 (M = Mo or W) and MoW(O2CtBu)4 and their radical cations prepared in situ by oxidation with Cp2FePF6. The EPR spectra of the radical cations are also reported. The EPR spectrum of the MoW(O2CtBu)4+ cation reveals that the unpaired electron is in a polarized MM delta orbital having 70% Mo and 30% W character. The MM stretching frequencies show good correlation with the MM bond lengths obtained from single-crystal X-ray diffraction studies of MoW(O2CtBu)4, W2(O2CtBu)4, and W2(O2CtBu)4+PF6- compounds, along with previously reported structures. These data provide benchmark parameters for valence trapped dicarboxylate bridged radical cations of the type [(tBuCO2)3M2]2(micro-O2C-X-CO2)+ (X = conjugated spacer).     

[C6N2H18]2[Mo5O15(HPO4)2]·H2O的水热合成与结构表征

通过水热法合成了一个新化合物[C6N2H18]2[Mo5O15(HPO4)2]·H2O,并通过IR光谱、ICP、元素分析、差热与热重分析和X射线单晶衍射分析等手段进行了表征.结果表明,晶体属三方晶系,P3(2)21空间群,a=1.1231(1)nm,c=2.2802(5)nm,V=2.4911(7)nm3,Dx=2.835Mg/m3,Z=6,最后的一致性因子R=0.0227,wR=0.0675.阴离子中Mo5O15构成一环状结构,2个HPO4一个连在环的下方,一个连在环的上方,形成类似于“飞碟”状的结构,阳离子为2个质子化的四甲基乙二胺.     

Formation of p-phenylenediamine-crown ether-[PMo12O40]4- salts

Electron transfer from the electron donor of p-phenylenediamine (PPD) to the electron acceptor of (H+)3[PMo12O40]3- forms a one-electron-reduced Keggin cluster of [PMo12O40]4-, bearing a S = 1/2 spin, while proton transfer from the proton donor of (H+)3[PMo12O40]3- to the proton acceptor of PPD yielded mono- and diprotonated cations of 4-aminoanilinium (HPPD+) and p-phenylenediammonium (H2PPD2+). By introduction of crown ether receptors during the crystallization process, supramolecular cations of (HPPD+)(crown ethers) and/or (H2PPD2+)(crown ethers) were successfully introduced into three new alpha-[PMo12O40]4- salts of (H2PPD2+)2([12]crown-4)4[PMo12O40]4- (1), (HPPD+)4([15]crown-5)4[PMo12O40]4- (2), and (HPPD+)2(H2PPD2+)([18]crown-6)4[PMo12O40]4- (3) as the countercation. The protonated states of PPD and molecular-assembly structures of the supramolecular cations depended on the size of the crown ethers. In salt 3, a novel mixed-protonated state of HPPD+ and H2PPD2+ was confirmed to be complexed in the cation structure. According to the changes in the cation structures, the anion arrangements were modulated from those of the two-dimensional layer for salt 1 to the isolated cluster for salts 2 and 3. The temperature-dependent magnetic susceptibilities of salts 1-3 were consistent with the isolated spin arrangements of [PMo12O40]4-. The electronic spectra of salts 1-3 indicated the intervalence optical transition from pentavalent Mo(V) to hexavalent Mo(VI) ions within the [PMo12O40]4- cluster. Temperature-dependent electron spin resonance spectra of salt 2 revealed the delocalization-localization transition of the S = 1/2 spin at 60 K. The spin on the [PMo12O40]4- cluster was localized on a specific Mo(V) site below 60 K, which was thermally activated with an activation energy of 0.015 eV.     

Structural, electrochemical and oxygen atom transfer properties of a molybdenum selenoether complex [Mo2O4(OC3H6SeC3H6O)2] and its thioether analogue [Mo2O4(OC3H6SC3H6O)2

The first crystallographically characterized molybdenum(vi) selenoether complex [Mo(2)O(4)(OC(3)H(6)SeC(3)H(6)O)(2)] and its thioether analogue [Mo(2)O(4)(OC(3)H(6)SC(3)H(6)O)(2)] were synthesised. Their structural, electrochemical and oxygen atom transfer properties are compared. This is relevant for the molybdenum cofactors of the DMSO reductase family where the coordination of the active site metal occurs through O (serine/aspartate), S (cysteine) or Se (selenocysteine). Both structures are almost identical except for those parameters that are directly derived from the different sizes of the varied ligand atoms (Se and S). No trans influence was observed. The metal centered redox process (Mo(V)<-->Mo(VI)) is at slightly lower voltage for the sulfur than for the selenium complex. The selenium compound catalyses the oxygen atom transfer from DMSO to PPh(3) by a different mechanism and at a higher rate than the sulfur compound, which is an indication that cysteine and selenocysteine might be used for a purpose in the different molybdenum and tungsten cofactors.     

有机-无机杂化材料[Na2(H2O)4]2[γ-Mo8O26·(Gly-Gly)2]·4H2O的合成及晶体结构

多金属氧酸盐因其独特的结构而具有较高的抗肿瘤及抗病毒活性,蛋白质和肽是氨基酸的聚合体,氨基酸侧链官能团能与多金属氧酸盐形成新型配合物.了解氨基酸和肽与多金属氧酸盐的相互作用对于深入研究多金属氧酸盐抗肿瘤及抗病毒机理很有意义.我们曾报道了赖氨酸、丙氨酸及甘氨酸二肽与钼磷酸所形成化合物的晶体结构.