Complexes of Zr<Superscript>IV</Superscript> and Hf<Superscript>IV</Superscript> with monolacunary Keggin-and Dawson-type anions

The reactions of the tetranuclear hydroxo complexes [M₄(μ₂-OH)₈(H₂O)₁₆]⁸⁺ (M = Zr or Hf) with the lacunary Keggin-type ([α-PW₁₁O₃₉]⁷⁻) and Dawson-type ([α ₂-P₂W₁₇O₆₁]¹⁰⁻) phosphotungstates in aqueous solutions produce the sandwich polyoxometalate complexes [M(α-PW₁₁O₃₉)₂]¹⁰⁻ (M = Zr (1) or Hf (2)) and [M(α ₂-P₂W₁₇O₆₁)₂]¹⁶⁻ (M = Zr (3) and Hf (4)). The complexes were isolated and structurally characterized as salts with potassium and dimethylammonium cations. The zirconium and hafnium atoms have a square antiprismatic coordination environment (coordination number is 8). In all complexes, the mutual arrangement of the ligands corresponds to the syn isomer. Hafnium complexes 2 and 4 are the first structurally characterized polyoxometalate complexes of this metal. The structures of the resulting compounds were confirmed also by ³¹P NMR spectroscopy in solution. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 214–218, February, 2007.     

钴镍取代杂多酸盐甘氨酸超分子化合物的合成及性质

Supermolecular compounds of glycine monosubstituted heteropolytungstates isomer with Keggin structure β_i-K_6-n(HGly)_n[SiW₁₁M(H₂O)O₃₉]·xH₂O (M=Co²⁺, Ni²⁺； β_i=β₂, β₃) were synthesized and characterized by means of elementary analysis, IR, UV, TG-DTA, X-ray diffraction, polarography and CV. The results indicate that glycin combines the electrostatic effect with heteropolytungstates isomer. The heteropoly anion still remains its Keggin structure in supermolecular compounds. The electrochemical behavior of the compound in 1 mol·L^-1 HAc-NaAc shows that two redox waves correspond to two two-electron processes attributing to the reduction of [SiW₁₁Co(H₂O)O₃₉]^6-. Steady-state fluorescence spectrum shows two intenser fluorescence emission peaks in 447 nm and 486 nm appeared after the supermolecular compound being excited by the excitation wavelength in 274 nm.     

纳米脂质体复合物-包封多酸化合物的合成,表征和生物活性研究

The polyoxometalate K6H[CoW11O39（CpTi）] （abbreviated as CoW11CpTi, Cp=η^5-C5H5） loaded nanosize-liposome complex has been prepared and structurally characterized by elemental analysis, IR and UV spectra. The particle size of the complex was distributed in the range of 100-250 nm with the average diameter of 132.6 nm. The result showed that the polyoxometalate retained the parent structure after being encapsulated by liposome and liposomal encapsulation increased the antitumoral activity of the polyoxometalate.     

[Zn(DMF)6]H2SiW12O40·(CH3)2NH的合成,晶体结构及性质

The title compound [Zn(DMF)₆]H₂SiW₁₂O₄₀·(CH₃)₂NH was synthesized in mixed solvent of aqueous and acetonitrile, and its crystal structure had been determined using single crystal X-ray diffraction. The crystal belongs to monoclinic, space group C2/m, a=2.0654(4)nm, b=1.3306(3)nm, c=1.3194(3)nm, β=119.59(3)°, V=3.1531(11)nm³, D_c=3.606Mg·m^-3, Z=2, R=0.0462, R_w=0.0836. The title compound comprises of a [Zn(DMF)₆]²⁺ unit, a polyanion and a free (CH₃)₂NH molecule. The ESR spectrum of the title compound shows that charge-transfer between organic groups and polyanion takes place under irradiation of the sunlight in solid state. The TG study of the title compound shows that it had four stages of the weight loss, and the increase of the de-composition temperature for the polyanion shows that the stability of the polyanion was enhanced due to the influence of Zn²⁺ ion. CCDC:175866.     

稀土钨青铜K0.71Nd0.028WO3的制备及其电性能

Tetragonal tungsten bronze K_0.71Nd_0.028WO₃ was synthesized by rare earth co-permeation method using Keggin type POMs of α-K₁₀[SiCu₃(OH₂)W₉O₃₇]·6H₂O (abbreviated as SiW₉Cu₃) as precursor. XRD, XPS, XRF, TG-DTA were used to characterize the resulting material. The XPS results indicate that Nd has permeated and diffused into the body of the sample and exists in tungsten bronze in the form of K_0.71Nd_0.028WO₃. The results of TG-DTA show that K_0.71Nd_0.028WO₃ begins to decompose at 320 ℃. The consequence of DC four-probe shows that the conductivity of the sample permeated by rare earth is 10³ times higher than that of the sample only permeated by methanol at room temperature. The conductivity of the sample only permeated by methanol is only 10^-3 S·cm^-1 but the conductivity of the sample permeated by rare earth is 1.65 S·cm^-1.     

复盐法制备无水氯化镁的热解机理及动力学研究

The complex compound (MgCl₂·C₆H₅NH₂·HCl·6H2O) was prepared by reaction of C₆H₅NH₂·HCl with MgCl₂·6H₂O. Reaction mechanism and kinetics of the compounds decomposition were studied by means of the TG-DTA-MS coupling technique and the TG-DTA technique. The results show that there are four steps in the complex′s thermal decomposition, the first two steps correspond to the loss of six crystal waters and the last two steps loss one Aniline hydrochloride. The first three steps belong to the R2 mechanism with 2-dimentional phase boundary reaction as the control step, and the last step belongs to the D3 with 3-dimensional diffusion (sphere Jander equ.) as the control step. The apparent active energy of four steps are, 127.4 kJ·mol^-1, 124.8 kJ·mol^-1, 142.3 kJ·mol^-1 and 329.0 kJ·mol^-1, respectively and the frequency factor are 1.28 × 10¹⁸ s^-1, 7.94 × 10¹⁵ s^-1, 5.98 × 10¹⁶ s^-1 and 4.39 × 10³⁴ s^-1, respectively.     

离子层气相反应法(ILGAR)制备CuInS2薄膜的研究

CuInS₂ thin films have been prepared by ion layer gas reaction (ILGAR) using C₂H₅OH as solvent, CuCl and InCl₃ as reagents and H₂S gas as sulfuration source. The effects of cationic concentrations and numbers of cycle on the properties of CuInS₂ film were investigated. The chemical composition, crystalline structure, surface topography, deposited rate, optical and electronic properties of the films were characterized by X-ray diffractrometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), ultraviolet-visible spectrometry (UV-Vis) and Hall System. The results show that the crystalline of CuInS₂ thin films and the deposition rate have been improved with the increase of cationic concentration, while CuxS segregation phases appear with further increasing cationic concentration. The deposition rate is close to constant as cationic concentration is fixed. CuInS₂ thin film derived form lower cationic concentration is uniform, compact and good in adhesion to the substrates. The absorption coefficient of CuInS₂ thin films is larger than 10⁴ cm^-1, and the band gap E_g is in the range of 1.30～1.40 eV. The dark resisitivity of the thin film decreases from 50 to 10 Ω·cm and the carrier concentration ranges are over 10¹⁶ cm^-3.     

Synthesis of a New Polyoxometalate Loaded Stearic Acid Nanoparticles

The stearic acid nanoparticles loaded polyoxometalate K6[γ-(CpTi)2SiW10O38][(CpTi)2SiW10] have been prepared and structurally characterized by elemental analysis, IR spectra.The particle size was estimated by transition electron microscope and zatesizer instrument. The result showed that the polyoxometalate retained the parent structure after encapsulation by stearic acid nanoparticles.     

Cu2(μ-dppb)2(μ-Cl)2的合成、晶体结构及非线性光学性质

The complex Cu₂(μ-dppb)₂(μ-Cl)₂ has been synthesized from the reaction of CuCl， dppb and (n-Bu)₄NCl. The crystal belongs to the triclinic with space group P1. The unit cell parameters are: a=9.939(4)?， b=10.083(6)?， c=14.104(5)?， α=76.46(3)°， β=71.02(2)°， γ=70.87(5)°. The single crystal X-ray diffraction analysis reveals that it has a bi-ring structure with a symmetry center at the middle of two Copper atoms. The outer ring is a 14-membered ring of Cu-dppb-Cu-dppb， and the inner ring is a 4-membered ring composed of two Cl^- and two Cu(Ⅰ). Investigation of third-order optical nonlinearity shows that it exhibits considerable nonlinear absorptive and self-defocusing effect with α₂=1.75×10^-13m·W^-1 and n₂=3.19×10^-18m²·W^-1. CCDC: 193113.     

不同配体对钌多吡啶配合物与DNA的作用和荧光性质的影响

Two polypyridyl ligands DCHIP (2-hydro-3，5-dichlorophenyl-imidazo[4，5-f][1，10] phenanthroline)，MDHIP(2，4-dihydrophenyl-imidazo[4，5-f][1，10]phenanthroline) and their ruthenium(Ⅱ) complexes [Ru(phen)₂MDHIP]²⁺ and [Ru(phen)₂DCHIP]²⁺ were prepared. Their DNA-binding properties were studied by spectroscopic methods and viscosity measurements. The results indicated that the complexes both bound to DNA by partial intercalation mode， but [Ru(phen)₂DCHIP]²⁺ exhibited stronger binding affinity for DNA than [Ru(phen)₂MDHIP]²⁺ due to the different planarities and steric effects of ligands. On the other hand， after binding to DNA， the fluorescence intensity of [Ru(phen)₂MDHIP]²⁺ decreased， while the fluorescence intensity of [Ru(phen)₂ DCHIP]²⁺ increased.     

β-K4H3[SiW9O37(CpTi)3]·11H2O环戊二烯钛多酸衍生物与DNA作用研究

某些过渡金属配合物具有特异性催化DNA和RNA断裂的功能, 因而研究过渡金属配合物对DNA和RNA的断链反应对新型抗肿瘤、抗艾滋病化学药物的定向设计及其基因治疗和分子生物学中DNA和RNA的高度专一性定点断裂、 DNA定位诱变和构象识别具有重要意义和应用前景[1,2]. 我们对二茂钛多酸有机金属衍生物合成及抗肿瘤活性研究表明, 环戊二烯钛多氧金属酸盐衍生物具有很高的抗肿瘤活性和较好的水溶性及稳定性, 有潜在的抗肿瘤药用价值[3].     

含硅多金属氧酸盐的抑菌作用

本文按文献方法合成了α-1,2,3-K6H[SiW9V3O40]、α-1,2-K6[SiW10V2O40]和α-K5[SiW11VO40](以下分别简写为α-SiW9V3,α-SiW10V2,α-SiW11V)3种多金属氧酸盐,并通过紫外和红外光谱对3种多金属氧酸盐化合物结构进行了表征。利用纸片法研究了3种钒取代的硅钨酸盐及硅钨酸（H4SiW12O40?xH2O,简写为SiW12）对大肠杆菌、枯草芽孢杆菌、酵母菌、黑曲霉和青霉的抑菌活性。结果表明：4种物质对大肠杆菌、枯草芽孢杆菌、酵母菌和黑曲霉均有不同程度的抑菌效果,但对青霉的抑菌效果较差。由于引起果蔬腐败的微生物主要有细菌、杆菌、霉菌和酵母菌等,本实验将为多金属氧酸盐作为广谱高效果蔬保鲜剂提供理论依据。     

Si取代Keggin型多酸催化光解水产氢机理

本文采用DFT和TD-DFT方法研究了Keggin型多酸[SiW12O40]4-光催化劈裂水产氢气机理。计算结果显示反应主要包括四个步骤：(i) 光激发,(ii) 电荷转移和生成单电子还原(OER)中间体,(iii) 生成双电子还原(TER)中间体,(iv)氢气从多酸表面解离和催化剂重生。当第一个电子从甲醇转移到多酸后,后续反应存在均为热力学上有利的放热途径,并推动第二个电子从甲醇自由基,H[SiW12O40]4-或[SiW12O40]5-转移到OER中间体H[SiW12O40]4-或[SiW12O40]5-生成TER中间体[SiW12O40]6-,H[SiW12O40]5-或H2[SiW12O40]4-,并伴随着H2产生。耦合的电子和质子转移路径在能量上最有利。甲醇和水分子的参与有利于H2产生。多酸在整个催化循环中,扮演了光敏剂、催化剂、电子的受体和给体。     

Layered assemblies of a dialuminum-substituted silicotungstate trimer and the reversible interlayer cation-exchange properties

Two polyoxometalate assemblies, TBA(9)[{γ-H(2)SiW(10)O(36)Al(2)(μ-OH)(2)(μ-OH)}(3)] (1; TBA = tetra-n-butylammonium) and TBA(6)Li(3)[{γ-H(2)SiW(10)O(36)Al(2)(μ-OH)(2)(μ-OH)}(3)]·18H(2)O (2), were synthesized by trimerization of a dialuminum-substituted silicotungstate monomer. Both 1 and 2 possessed a layered structure composed of a basal sheet unit [TBA(3){γ-H(2)SiW(10)O(36)Al(2)(μ-OH)(2)(μ-OH)}(3)](6-) and interlayer cations. The interconversion between 1 and 2 reversibly took place through interlayer cation exchange.     

Preparation and application of multiple-component-doped keggin polyoxometalate microtubes--towards a component-tunable hollow structure

In this paper, the preparation of ascorbic acid (AA)-doped polyoxometalate (SiW(12)-AA) microtubes is described. The SiW(12)-AA microtubes convert to heteropoly blue microtubes upon exposure to ammonia gas, which is an ammonia-triggered solid-solid redox reaction between AA molecules and polyoxometalates, and can possibly be applied to a chemical sensor for detecting ammonia and volatile organic amines. Furthermore, the SiW(12)-AA microtubes have been applied to the in situ synthesis of Ag nanoparticles (NPs) through the redox reaction between the AA component and Ag(+) ions occurring on the surfaces of the SiW(12)-AA microtubes to give silver NPs immobilized on polyoxometalate microtubes (Ag@SiW(12)).     

A Novel Optical Complex between an Organic Substrate and a Polyoxometalate. Crystal and Molecular Structure of alpha-H(4)SiW(12)O(40).4HMPA.2H(2)O (HMPA = Hexamethylphosphoramide)

A solvated complex of alpha-H(4)SiW(12)O(40).4HMPA.2H(2)O composed the heteropolytungstate alpha-H(4)SiW(12)O(40) and the organic substrate hexamethylphosphoramide (HMPA) has been synthesised, purified, and characterized. The electronic spectra (lambda = 220-500 nm) as well as the (1)H NMR spectra for the title compound dissolved in CD(3)CN establish that this complex dissociates into free SiW(12)O(40)(4)(-) and HMPA moieties in solution unless the organic substrate HMPA is present in very high concentrations. The solid reflectance electronic spectra and IR spectra indicate that there is interaction between the alpha-H(4)SiW(12)O(40) and the organic substrate. The complex has no photosensitivity under irradiation of sunlight, but under the near-UV light result in a charge transfer by oxidation of the HMPA and the reduction of the polyoxometalate. Light yellow polyhedrons of the title compound crystallize from the aqueous solvent of acetonitrile and aqueous solution as the formula of alpha-H(4)SiW(12)O(40).4HMPA.2H(2)O in the monoclinic, space group P2(1). The unit cell has a = 12.791(3) ?, b = 22.103(6) ?, c = 15.532(4) ?, beta = 102.860(10) degrees, and Z = 2. From the bond-valence parameters, it was found that the four hydrogen atoms of the polyoxometalate were combined with the N atoms of the four HMPA respectively. The title compound shows a certain second-order and third-order nonlinear optical response of I(2)(omega) = 0.7I(2)(omega)(KDP) and chi((3)) = 2.63 x 10(-)(11) esu, respectively.     

A discrete conglomerate of a distorted Mo(v)-porphyrin with a directly coordinated Keggin-type polyoxometalate

The reaction of a saddle-distorted Mo(v)-dodecaphenylporphyrin complex and a Keggin-type polyoxometalate gives a discrete and nanosized molecule, [{Mo(DPP)(O)}(2)(H(2)SiW(12)O(40))], which involves direct coordination between the Mo(v) centers and terminal oxo groups of the polyoxometalate and exhibits excellent stability in solution to show reversible multi-redox processes.     

Selective precipitation of prions by polyoxometalate complexes

The efficacy of a variety of polyoxometalate anions in selectively precipitating the infectious isoform of the prion protein (PrPSc) over the normal, cellular protein (PrPC) was tested as a means of improving the sensitivity of a conformation-dependent immunoassay (CDI). Experiments utilizing neutralized aqueous solutions containing MgCl2.6H2O and Na2H[PW12O40] (1) indicated that use of the former is detrimental to selectivity, while use of the latter gives optimal selectivity at a concentration of 2.48% w/v, much higher than the 0.31% w/v employed in the current CDI protocol. Similar experiments using Na4[SiW12O40] (2), K5[BW12O40] (3), and Na6[H2W12O40] (4) were performed to probe the role of charge density in polyoxometalate anions possessing the Keggin structure. These, coupled with assignment of solution structures via NMR and infrared spectroscopy, revealed the following trend in optimal concentrations: [HBW11O39]8- < [SiW11O39]8- < [PW11O39]7- = [H2W12O40]6-. Interestingly, use of the salts K10[Zn4(H2O)2(PW9O34)2] (5), Na16[Zn4(H2O)2(P2W15O56)2] (6), and Na27[NaAs4W40O140] (7), containing larger polyoxometalate anions, was found to suppress PrPSc precipitation in a concentration-dependent manner. Taken together, the results suggest a precipitation mechanism wherein Keggin-type anions link multiple PrPSc moieties by binding a somewhat hindered cleft featuring one or more positively charged residues.