银配合物[Ag_(10)(NCA)_4(PW_9~ⅥW_3~ⅤO_(40))(H_2O)_4]的合成、结构与性质

在水热条件下,制备了一种基于Keggin型多金属氧酸盐的银配合物[Ag_(10)(NCA)_4(PW_9~ⅥW_3~ⅤO_(40))(H_2O)_4].通过元素分析、红外光谱和X-射线单晶衍射方法确定了该配合物的晶体结构.在合成过程中,3-(2-吡啶羧酸)酰胺-吡嗪配体(L)分解成烟酸NCA.结构分析表明:该化合物属于三斜晶系,P_1空间群,晶胞参数a=1.188 74(9)nm,b=1.249 50nm,c=1.411 03(10)nm,α=73.712(2)°,β=66.720(2)°,γ=83.467(2)°,V=1.847 9(2)nm~3,Z=1,R_1=0.073 1,ωR_2=0.197 4.配合物中含有一种六核银亚单元[Ag_6(NCA)_4]~(2+),不同亚单元间通过配位水的氧原子连接形成一维双链结构,而一维双链进一步通过Ag—N键连接形成二维层状结构,二维层则通过[PW_9~ⅥW_3~ⅤO_(40)]~(6-)多阴离子形成最终的三维金属有机框架.标题配合物修饰的碳糊电极对H_2O_2和KNO_2还原有好的电催化活性,而且该配合物对降解亚甲基蓝、罗丹明B分子有较高的光催化效率.     

以[As_2W_(19)O_(67)(H_2O)]~(14-)单元和Ce~(3+)构筑的二聚的砷钨酸盐的合成、结构及表征

以介稳态的K_(1 4)[As_2W_(19)O_(67)(H_2O)]为多酸前驱体与Ce Cl_3·6H_2O和2,6-吡啶二羧酸反应,采用常规水溶液合成法制得了二聚的且保持多酸前驱体[As_2W_(19)O_(67)(H_2O)]~(14-)结构骨架的多酸基稀土衍生物K_(14)H_8{Ce(H_2O)_3[As_2W_(19)O_(67)(H_2O)]}_2·48H_2O(1),并测定了其晶体结构.同时,通过红外光谱以及热分析对其进行了表征.X射线单晶结构分析表明,化合物1属于三斜晶系,P-1空间群,晶胞参数为a=1.241 13(5)nm,b=1.842 15(8)nm,c=2.193 97(9)nm,α=69.966 0(10)°,β=77.803 0(10)°,γ=77.926 0(10)°,Z=1,M_r=11 125.90,V=4.554 9(3)nm~3,μ=25.519 mm~(-1),R_1=0.045 9,wR_2=0.117 2[I2σ(I)].化合物1是二聚结构,其中Ce~(3+)离子采用八配位畸变的双加冠三棱柱配位构型.     

基于一维[H_2Mo_4O_(14)]_n~(2n-)链和双吡啶双酰胺配体的三维锌配合物的合成、结构与性能

选择柔性的双吡啶双酰胺配体N,N'-双(3-吡啶甲酰胺基)-1,2-乙烷(3-bpye)、钼酸铵和氯化锌在水热条件下自组装制备了一个基于一维[H_2Mo_4O_(14)]_n~(2n-)链的三维锌配合物[Zn(3-bpye)(H_2Mo_4O_(14))(H_2O)_2],并通过元素分析、红外光谱、热重分析等技术手段研究了配合物的结构,并利用X射线单晶衍射分析进行了晶体结构表征。结构解析揭示标题配合物是三斜晶系,P-1空间群,晶胞参数a=0.61310(3)nm,b=1.04750(6)nm,c=1.06540(6)nm,α=78.5540(10)°,β=77.5350(10)°,γ=89.9050(10)°,V=0.65420(6)nm~3,M_r=981.47,D_c=2.491 g/cm~3,Z=1,F(000)=468,R_1=0.0290,ωR_2=0.1068。标题配合物中,金属锌离子连接一维[H_2Mo_4O_(14)]_n~(2n-)链形成一种二维无机双金属层[Zn(H_2Mo_4O_(14))]_n,相邻的层间又通过双齿配体3-bpye连接形成三维CdSO_4拓扑的骨架结构。配合物表现出强的荧光发射特性,而且其在紫外光照下对亚甲基蓝和罗丹明B均有明显的催化降解活性。     

新型仲钨酸盐-B化合物[Na_2(H_2O)_(10)][Cu_4(H_2O)_(12)(H_2W_(12)O_(42))]·15H_2O体外抗肿瘤活性研究

对化合物[Na_2(H_2O)_(10)][Cu_4(H_2O)_(12)(H_2W_(12)O_(42))]·15H_2O(简称Na_2Cu_4W_(12))进行了体外抗肿瘤活性研究.应用四甲基偶氮唑盐(3-[4,5-dimethylthiazo-2-y]-2,5-diphenyltetrazolium bromide,MTT)比色法分析Na_2Cu_4W_(12)对人肝癌细胞(Hep G2)、人神经母细胞瘤细胞(SHY5Y)增殖抑制活性.采用光学显微镜观察肿瘤细胞的凋亡形态变化,用流式细胞术分析细胞周期和细胞凋亡,计算各期细胞比例及细胞凋亡率.结果表明,Na_2Cu_4W_(12)对Hep G2和SHY5Y 2种肿瘤细胞增殖半数抑制浓度IC_(50)值分别为5.3和10.2μmol·L~(-1),且呈剂量依赖性.光学显微镜下处理组细胞出现皱缩、变圆、缩小等形态变化,不同浓度Na_2Cu_4W_(12)处理12h早期凋亡细胞所占的百分比显著增加且呈剂量依赖性.综上所述,Na_2Cu_4W_(12)能够抑制胞瘤细胞增殖,诱导细胞凋亡.     

[Ho_2(phen)_4(H_2O)_4(OH)_2](phen)_2(NO_3)_4的合成、晶体结构及磁性

在甲醇与水的混合溶剂中,经浓硝酸硝化的Ho_2O_3与1,10-邻菲啰啉反应形 成氢氧根桥联的双核钬配合物[Ho_2(phen)_4(H_2O)_4(OH)_2] (phen)_2(NO_3)_4 （phen = 1,10-邻菲啰啉）。单晶X射线衍射晶体结构测定表明晶体属三斜晶系, P1-bar (no. 2)空间群,晶胞参数a = 1.1241(1) nm, b = 1.1439(1) nm, c = 1. 4058 (1) nm, α = 93.989(7)°, β = 98.173(7)°, γ = 108.19(1)°, V = 1.6874(4) nm~3, Z = 1, D_c = 1.737 g/cm~3, F(000) = 880,7752个独立衍射 点中,5702个可观测点满足F_o~2 ≥ 2σ (F_o~2),R_1 = 0.0499, wR_2 = 0. 858。标题配合物由中心对称的双核[Ho_2(phen)_4(H_2O)_4-(OH)_2]~(4+)配阳离 子,邻菲啰啉phen分子及硝酸根NO_3~-阴离子组成。敏个稀土原子与2个邻菲啰啉 配体,2相水分子和2个氢氧根配位形成配位数为8的[HoN_4O_4]四方反棱柱。配位 多面体通过两氢氧根基团形成共棱的[Ho_2N_8O_6]双四方反棱柱[d(Ho-N) = 0. 2549～0.2565 nm, d(Ho-O_(H_2O) = 0.2356, 0.2366 nm, d(Ho-O_(OH)) = 0. 2223, 0.2240 nm]。通过氢键和芳环堆积作用,配阳离子和邻菲啰啉分子排列形成 平行于（10 1-bar）的两维层结构,NO_3~-阴离子位于层之间。标题配合物为顺磁 物质,在5 ～300K区间内遵循Curie-Weiss定律X_m (T + 4.43) = 14.72 cm~3·K ·mol~(-1)(X_m为每摩尔Ho~(3+)离子磁化率）,其Ho~(3+)离子的室温有效磁矩为 10.76 B. M.,与Ho~(3+)自由离子的磁矩基本相同,表明稀土离子间不存在磁交换 作用。     

九配位K_3[Ho(nta)_2(H_2O)]·5H_2O和八配位NH_4[Ho(cdta)(H_2O)_2]·4.5H_2O配合物的合成及结构

报道了稀土金属Ho~(III)离子氨基多羧酸（nta=氨基三乙酸,cdta=反式-1, 2-环乙二氨四乙酸）配合物的合成及分子结构和晶体结构的测定。具体结果如下： （a)分子式K_3[Ho(nta)_2(H_2O)]·5H_2O,单斜晶系,C2/c空间群,a = 1.5364 (8) nm, b = 1.2881(7) nm,c = 2.6163(13) nm, β = 96.140(9)°, V = 5. 416(5) nm~3,Z = 8,D_c = 1.932 g/cm~3, μ = 3.635 nm~(-1)和F(000) = 2944。其R和R_w值分别为0.0310和0.0675(对4509个独立的衍射点）,R和R_w值分 别为0.0442和0.0707（对所有10336个衍射点）。K_3[Ho(nta)_2(H_2O)]·5H_2O配 合物中,Ho~(III)N_2O_7部分是一个九配位单帽四方反棱柱体结构。(b)分子式 NH_4[Ho(cdta)(H_2O)_2]·4.5H_2O,三斜晶系,P1,空间群,a = 0.8636(3) nm, b = 1.0072(3) nm, c = 1.4457(5) nm, α = 88.382(5)°, β = 75.275(5)°, γ = 88.382(5)°, V = 1.2154(7) nm~3, Z = 2, D_c = 1.657 g/cm~3, μ = 3.315 nm~(-1)和F(000) = 606。其R和R_w值分别为0.0283和0.0708（对4203个独 立的衍射点）,R和R_w值分别为0.0325和0.0730(对所有4595个衍射点）。NH_4 [Ho(cdta)(H_2O)_2]·4.5H_2O配合物中Ho~(III)N_2O_6部分是一个八配位四方反 棱柱体结构。     

基于[As_2W_(19)O_(67)(H_2O)]~(14-)构筑的含镧砷钨酸盐的合成和结构表征

通过水热法合成了一例[As_2W_(19)O_(67)(H_2O)]~(14-)({As_2W_(19)})构型保持的稀土衍生物K_(14)H_8[La(H_2O)_3As_2W_(19)O_(67)(H_2O)]_2·53H_2O(1),并测定了其晶体结构.同时,通过红外光谱、粉末衍射(XRPD)以及热分析对其进行了表征.X射线单晶结构分析表明,化合物1属于三斜晶系,P-1空间群,晶胞参数为a=1.239 5(10)nm,b=1.847 8(16)nm,c=2.268 5(19)nm,α=68.366(12)°,β=78.215(13)°,γ=78.406(12)°,Z=1,Mr=11 351.63,V=4.683(7)nm3,μ=24.794mm-1,R1=0.056 4,wR2=0.150 8[I2σ(I)].化合物1是二聚结构,其中LaIII离子采用九配位畸变的单加冠四方反棱柱配位构型.     

基于{PMo_(12)O_(40)(VO)_(0.5)}的Cu(Ⅰ)配合物的合成及荧光性质研究

利用磷钼十二酸、偏钒酸铵、CuCl_2·2H_2O和3,3′,5,5′-四甲基-4,4′-联邻二氮杂茂(H_2X)在水热条件下反应,合成出了1个新的多酸基杂化化合物Cu_4(H_2X)_4[(PMo_(12)O_(40)(VO)_(0.5))].通过X射线单晶衍射、红外光谱和热重分析等测试手段对该化合物进行了结构表征.单晶结构解析表明该化合物为2D层状化合物,属于单斜晶系,C2/c空间群,晶胞参数a=2.637 6(5)nm,b=1.542 2(5)nm,c=2.057 0(5)nm,α=90.000(5)°,β=112.677(5)°,γ=90.000(5)°,V=7.720(3)nm~3,Z=4,R_1=0.061 5,wR_2=0.164 6.     

基于[As_2W_(19)O_(67)(H_2O)]~(14-)构筑块的单核铥夹心型化合物的合成、结构及热稳定性

以缺位结构钨酸盐K_(14)[As_2W_(19)O_(67)(H_2O)]为多酸前驱体与TmCl_3·7H_2O和2,6-吡啶二羧酸反应,采用常规水溶液合成法制得了一例单核铥夹心的多酸基稀土衍生物K_8H_3[Tm(H_2O)_2(As_2W_(19)O_(67))(H_2O)]·15H_2O(1),并通过X射线单晶衍射、红外光谱、变温红外光谱、紫外光谱、热重分析等方法对该化合物进行了测试和表征.X射线单晶衍射分析表明,化合物1属于单斜晶系,P-1空间群,晶胞参数a=1.253 44(6)nm,b=1.761 45(9)nm,c=2.114 66(11)nm,α=73.300 0(10)°,β=85.771 0(10)°,γ=89.948 0(10)°.该聚阴离子是由两个{AsW9}构筑块与{WO(H_2O)}片段和铥离子相连形成的夹心结构;用热重分析和变温红外光谱对化合物1的热性质进行了研究,结果表明,化合物1阴离子结构在400℃以内是对热稳定的.     

单核镥取代的砷钨酸盐的合成、结构及表征

以双缺位结构钨酸盐K_(14)[As_2W_(19)O_(67)(H_2O)]为多酸前驱体与LuCl_3·6H_2O和2,6-吡啶二羧酸在常规水溶液中反应,制得了一例单核镥夹心的砷钨酸盐稀土衍生物K_8H_3[Lu(H_2O)_2(As_2W_(19)O_(67))(H_2O)]·39H_2O(1),并通过X射线单晶衍射、红外光谱、热重分析等方法对该化合物进行了测试和表征.X射线单晶衍射分析表明,化合物1属于单斜晶系,P-1空间群,晶胞参数a=1.253 54(9)nm,b=1.757 83(13)nm,c=2.111 40(16)nm,α=73.326 0(10)°,β=85.721 0(10)°,γ=89.856 0(10)°.该聚阴离子是由一个镥离子镶嵌在[As_2W_(19)O_(67)(H_2O)]~(14-)({As_2W_(19)})阴离子的缺位处构成的;热重分析结果表明,化合物1阴离子结构在400℃以内是对热稳定的.     

Dielectric characteristics of O2(H2O)i and (O2)2(H2O)i clusters. Computer-aided experiment

Absorption of oxygen molecules by water clusters with sizes of 10 ≤ i ≤ 50 is studied by the molecular dynamics method using the modified TIP4P model. It is revealed that the total dipole moment of the clusters nonmonotonically increases with their sizes. Absorption of O₂ molecules tends to raise the static permittivity of the ultradispersed medium formed by the clusters. The real and imaginary parts of the permittivity of water clusters with absorbed O₂ molecules are aperiodic functions of frequency. The permittivity components turn out to be nonmonotonic functions of cluster sizes. The IR absorption and reflectance spectra are calculated for clusters of pure water and aggregates with absorbed O₂ molecules. After the addition of oxygen molecules, the absorption coefficient of the clusters decreases, while the reflection coefficient increases. It is concluded that the capture of oxygen molecules by atmospheric moisture may reduce the greenhouse effect. Original Russian Text ? A.E. Galashev, V.N. Chukanov, O.A. Galasheva, 2006, published in Kolloidnyi Zhurnal, 2006, Vol. 68, No. 2, pp. 155–160.     

Diffusivity fractionations of H2(16)O/H2(17)O and H2(16)O/H2(18)O in air and their implications for isotope hydrology

We have determined the isotope effects of (17)O and (18)O substitution of (16)O in H(2)O on molecular diffusivities of water vapor in air by the use of evaporation experiments. The derived diffusion fractionation coefficients (17)alpha(diff) and (18)alpha(diff) are 1.0146 +/- 0.0002 and 1.0283 +/- 0.0003, respectively. We also determined, for the first time, the ratio ln((17)alpha(diff))/ln((18)alpha(diff)) as 0.5185 +/- 0.0002. This ratio, which is in excellent agreement with the theoretical value of 0.5184, is significantly smaller than the ratio in vapor-liquid equilibrium (0.529). We show how this new experimental information gives rise to (17)O excess in meteoric water, and how it can be applied in isotope hydrology.     

Proton magnetic shielding in H2O and (H2O)2

The proton magnetic shielding constants in the water molecule and its linear perpendicular dimer are computed from SCF-MO-LCGO wave functions by using the uncoupled Hartree-Fock variation-perturbation procedure due to Karplus and Kolker. The convergence of the calculated shielding constants as well as their gauge dependence is studied. The final results for 17-term polynomial variation function indicate that the best choice for the gauge origin corresponds to the molecular electronic centroid.The calculated proton magnetic shielding constant in the water molecule is in remarkable agreement with experimental data and favourably compares with the best coupled Hartree-Fock results. It follows from the calculations for the water dimer that the H-bond NMR-shift amounts in this case —1.0 ppm and qualitatively agrees with the experimental data for the liquid water.     

Ferromagnetism in malonato-bridged copper(II) complexes. Synthesis,crystal structures,and magnetic properties of [[Cu(H2O)3][Cu(mal)2(H2O)]]n and [[Cu(H2O)4]2[Cu(mal)2(H2O)]][Cu(mal)2(H2O)2][[Cu(H2O)4][Cu(mal)2(H2O)2][(H2mal = malonic acid)

Three malonato-bridged copper(II) complexes of the formulas [[Cu(H2O)3][Cu(C3H2O4)2(H2O)]]n (1), [[Cu(H2O)4]2[Cu(C3H2O4)2(H2O)]] [Cu(C3H2O4)2(H2O)2][[Cu(H2O)4][Cu(C3H2O4)2(H2O)2]] (2), and [Cu(H2O)4][Cu(C3H2O4)2(H2O)2] (3) (C3H2O4 = malonate dianion) have been prepared, and the structures of the two former have been solved by X-ray diffraction methods. The structure of compound 3 was already known. Complex 1 crystallizes in the orthorhombic space group Pcab, Z = 8, with unit cell parameters of a = 10.339(1) A, b = 13.222(2) A, and c = 17.394(4) A. Complex 2 crystallizes in the monoclinic space group P2/c, Z = 4, with unit cell parameters of a = 21.100(4) A, b = 21.088(4) A, c = 14.007(2) A, and beta = 115.93(2) degrees. Complex 1 is a chain compound with a regular alternation of aquabis(malonato)copper(II) and triaquacopper(II) units developing along the z axis. The aquabis(malonato)copper(II) unit acts as a bridging ligand through two slightly different trans-carboxylato groups exhibiting an anti-syn coordination mode. The four carboxylate oxygens, in the basal plane, and the one water molecule, in the apical position, describe a distorted square pyramid around Cu1, whereas the same metal surroundings are observed around Cu2 but with three water molecules and one carboxylate oxygen building the equatorial plane and a carboxylate oxygen from another malonato filling the apical site. Complex 2 is made up of discrete mono-, di-, and trinuclear copper(II) complexes of the formulas [Cu(C3H2O4)2(H2O)2]2-, [[Cu(H2O)4] [Cu(C3H2O4)2(H2O)2]], and [[Cu(H2O)4]2[Cu(C3H2O4)2(H2O)]]2+, respectively, which coexist in a single crystal. The copper environment in the mononuclear unit is that of an elongated octahedron with four carboxylate oxygens building the equatorial plane and two water molecules assuming the axial positions. The neutral dinuclear unit contains two types of copper atoms, one that is six-coordinated, as in the mononuclear entity, and another that is distorted square pyramidal with four water molecules building the basal plane and a carboxylate oxygen in the apical position. The overall structure of this dinuclear entity is nearly identical to that of compound 3. Finally, the cationic trimer consists of an aquabis(malonato)copper(II) complex that acts as a bismonodentate ligand through two cis-carboxylato groups (anti-syn coordination mode) toward two tetraaqua-copper(II) terminal units. The environment of the copper atoms is distorted square pyramidal with four carboxylate oxygens (four water molecules) building the basal plane of the central (terminal) copper atom and a water molecule (a carboxylate oxygen) filling the axial position. The magnetic properties of 1-3 have been investigated in the temperature range 1.9-290 K. Overall, ferromagnetic behavior is observed in the three cases: two weak, alternating intrachain ferromagnetic interactions (J = 3.0 cm-1 and alpha J = 1.9 cm-1 with H = -J sigma i[S2i.S2i-1 + alpha S2i.S2i+1]) occur in 1, whereas the magnetic behavior of 2 is the sum of a magnetically isolated spin doublet and ferromagnetically coupled di- (J3 = 1.8 cm-1 from the magnetic study of the model complex 3) and trinuclear (J = 1.2 cm-1 with H = -J (S1.S2 + S1.S3) copper(II) units. The exchange pathway that accounts for the ferromagnetic coupling, through an anti-syn carboxylato bridge, is discussed in the light of the available magneto-structural data.     

One‐dimensional Cadmium(II) Coordination Polymers: Syntheses and Crystal Structures of [Cd(H2O)3(C5H6O4)]·2H2O,Cd(H2O)2(C6H8O4), and Cd(H2O)2(C8H12O4)

[Cd(H₂O)₃(C₅H₆O₄)]·2H₂O ( 1 ) and Cd(H₂O)₂(C₆H₈O₄) ( 2 ) were prepared from reactions of fresh CdCO₃ precipitate with aqueous solutions of glutaric acid and adipic acid, respectively, while Cd(H₂O)₂(C₈H₁₂O₄) ( 3 ) crystallized in a filtrate obtained from the hydrothermal reaction of CdCl₂·2.5H₂O, suberic acid and H₂O. Compound 1 consists of hydrogen bonded water molecules and linear {[Cd(H₂O)₃](C₅H₆O₄)_2/2} chains, which result from the pentagonal bipyramidally coordinated Cd atoms bridged by bis‐chelating glutarato ligands. In 2 and 3 , the six‐coordinate Cd atoms are bridged by bis‐chelating adipato and suberato ligands into zigzag chains according to {[Cd(H₂O)₃](C₅H₆O₄)_2/2} and {[Cd(H₂O)₂](C₈H₁₂O₄)_2/2}, respectively. The hydrogen bonds between water and the carboxylate oxygen atoms are responsible for the supramolecular assemblies of the zigzag chains into 3D networks. Crystallographic data: ( 1 ) P1¯ (no. 2), a = 8.012(1), b = 8.160(1), c = 8.939(1) Å, α = 82.29(1)°, β = 76.69(1)°, γ = 81.68(1)°, U = 559.6(1) ų, Z = 2; ( 2 ) C2/c (no. 15), a = 16.495(1), b = 5.578(1), c = 11.073(1) Å, β = 95.48(1)°, U = 1014.2(1) ų, Z = 4; ( 3 ) P2/c (no. 13), a = 9.407(2), b = 5.491(1), c = 11.317(2) Å, β = 95.93(3)°, U = 581.4(2) ų, Z = 2.     

Fe2P2O7(H2O)2

The compound diiron diphosphate dihydrate, Fe₂P₂O₇(H₂O)₂, was synthesized hydro­thermally and crystallizes in the monoclinic space group P2₁/n. The compound has a somewhat open framework made up of edge‐sharing iron(II) octahedra that form chains connected by five bridging diphosphates. The remaining octahedral site of each iron is occupied by coordinated water. The H atoms of the water molecules all point into a common channel.     

K2[Mo2O4(C2O4)2(H2O)2]·3H2O

The crystal and molecular structure of dipotassium di‐μ‐oxo‐bis[aqua(oxalato‐O¹,O²)oxomolybdenum(III)] trihydrate, K₂­[Mo₂O₄(C₂O₄)₂(H₂O)₂]·3H₂O, has been determined from X‐ray diffraction data. In the dimeric anion, which has approximate twofold symmetry, each Mo atom is in a distorted octahedral coordination, being bonded to one terminal oxo‐O atom, two bridging O atoms, two O atoms from the oxalato ligand and one from the water mol­ecule. Bond lengths trans to the multiple‐bonded terminal oxo ligand are larger than those in the cis position, confirming the trans influence as a generally valid rule.     

Lowest-energy structures of water clusters (H2O)11 and (H2O)13

We employed a four-step searching/screening approach to determine best candidates for the global minima of (H2O)11 and (H2O)13. This approach can be useful when there exist a large number of low-lying and near-isoenergetic isomers, many of which have the same oxygen-skeleton structure. On the two new candidates for the global minimum of (H2O)11, one isomer can be viewed as placing the 11th molecule onto the side of the global minimum of (H2O)10 and the other can be viewed as removing the 12th molecule from the middle layer of the global minimum of (H2O)12. The three leading lowest-energy clusters of (H2O)13 can all be built starting from the global minimum of (H2O)12, with the difference being in the location of the 13th water molecule.