[Na(DB18C6)(CH3CN)]2W6O19·(CH3CN)2的合成、晶体结构及谱学表征

A super-molecular complex, [Na(DB18C6)(CH₃CN)]₂W₆O₁₉·(CH₃CN)₂, was obtained by solvothermal reaction and characterized by IR , ¹H NMR, gumbc spectrum single crystal and X-ray diffraction. The compou- nd crystallizes in monoclinic space group P2₁/c with a=1.185 22(4) nm, b=2.091 51(8) nm, c=1.487 19(5) nm, β=117.467(2)° and Z=2. The complex contains four basic units: Na⁺, CH₃CN, DB18C6 and W₆O₁₉^2-. Sodium ions located in the cavity of dibenzo-18-crown-6 with 6 Na-O bonds and the crown ether-sodium ion complex is supported on the terminal oxygen atoms of the typical Lindqvist isopolyanion W₆O₁₉^2- via the coordinative interactions. W₆O₁₉^2- located between two DB18C6 and led to the formation of the “hamburger” structure. Two isolated CH₃CN are included in the complex. The whole title crystal is stabilized by van der waals force. CCDC: 292369.     

Synthesis,Crystal Structure of Cis—dioxo—catecholatotungsten（VI） Complex and Its NMR Studies on the Interaction with ATP

Cis-dioxo-catecholatotungsten(VI) complex anion[W^(VI)O2-(OC6H4O)2]^2- was obtained with discrete protonated ethylenediamine (NH2CH2CH2NH3)^ cations by the reaction of tetrabutyl ammonium decatungstate with catechol in the mixed solvent of CH3OH,CH3CN and ethylenediamine,and compared with its molybdenum anaogue [Mo^(V) O2(OC6H4O)2]^3- by crystal structure,UV,EPR,The results of the UV and EPR spectra show that tungsten is less redox active than molybdenum since the molybdenum is reduced from Mo(VI) to Mo(V) but tungsten stays in the original highest oxidized state Mo(VI) when they are crystallized from the solution above.It is worthy to note that [W^(VI)O2(OC6H4O)]^2- shows the same coordination structure as its molybdenum analogue in which the metal center exhibits distorted octahedral coordination geometry with two cis-dioxocatecholate ligands and might have the related coordination structure feature with the cofactor of flavoenzyme because [Mo^(V)O2(OC6H4O)2]^3- presented essentially the same EPR spectra as flavoenzyme.The NMR studies on the interaction of the title complex with ATP reveal that the reduction of W(VI) to W(V) occurs when the title complex is dissolved in D2O and the W(V) is oxidized again when ATP solution is mixed with original solution and the hydrolysis of the catecholato ligand take places at mean time being monitored by ^1H NMR and ^13C NMR spectra.     

[(NH2CH2CH2NH3)2WⅥO2(NHC6H4NH)2]2(NH2CH2CH2NH2)·H2O配合物的合成与晶体结构

Cis-dioxo-tungsten(Ⅵ) complex, (NH₂CH₂CH₂NH₂)[(NH₂CH₂CH₂NH₃)₂W^ⅥO₂(NHC₆H₄NH)₂]₂·H₂O is synthesized at room temperature by the reaction of sodium tungstate with o-phenylenediamine. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P2₁/ c, a=0.712 8(2) nm, b=3.081 1(10) nm, c=0.981 9(3) nm, β=102.615(4)°, V=2.104 4(11) nm³, Z=2, μ=55.26 cm^-1, F(000)=1 176. Compared the complex with its analogous biomimetic complexes of the cofactor of molybdoenzymes and tungstoenzymses, it is found that the variance of the coordination atoms and the metal ions center have no influence on the coordination feature, and exhibits distored octahedral coordination with cis-dioxo o-phenylenediamine. CCDC: 252834.     

苯并15冠5与钼多酸的组装

以苯并15冠5和钼多酸为原料, 用水热法合成了两个新颖的超分子配合物[Na(B30C10)][Mo₆O₁₉] (1)和[NaL(CH₃CN)][NaL][α-PMo₁₂O₄₀][NaL₂] (L＝B15C5) (2), 并用单晶X射线衍射测定了它们的晶体结构. 配合物1属单斜晶系, 空间群为C2/m, 它包含三个基本单元: Na^＋, B15C5和Mo₆O , 冠醚分子和Na^＋配位, 并通过静电作用力和多酸分子相连. 配合物2属三斜晶系, 空间群为P-1, 它包含一个[α-PMo₁₂O₄₀]^3－离子和三个钠离子配合物. [Na(B15C5)]^＋通过Mo-O-Na-O键和多酸阴离子相连.     

钨多酸的抗艾滋病活性

回顾了钨多酸抗艾滋病研究的历史;简要介绍了钨多酸的药物动力学、抗HIV作用机理和选择性;总结了研究过程中的检测手段;预测了未来钨多酸抗HIV研究工作的方向。     

钨酶的研究进展

钨酶是近年来才发现的存在于生物体内具有特殊生化活性的重要物质.本文主要介绍钨酶的类型、钨酶活性端的结构以及钨酶的光谱性质,并对钨酶的近期研究进展进行综述.     

用19F NMR参比积分法测Ba2+与18-冠-6络合物的稳定常数

提出了一种间接的但十分简单的方法测定Ba²⁺与18-冠-6的络合平衡常数。在不同浓度的18-冠-6水溶液中,分别加入难溶盐BaF₂。使其饱和,然后对各溶液进行¹⁹F NMR定量测定。根据络合平衡和难溶盐的溶解平衡,确定了Ba²⁺与18-冠-6的络合平衡常数。     

N-对氯苯基氮杂15冠5八钼多酸钠超分子配合物的结构与热分解

本文对新型超分子配合物［Na(N-(p-ClPh)-15-C-5(Et₂O)］₂N₂Mo₈O₂₆进行了X-射线四圆衍射测定，该晶体属单斜晶系，空间群为P2₁/c,a=1.7803(4), b=1.3674(3), c=1.4610(3)(nm), β=112.33(2)°, 相似文献   

苯基氮杂—15—冠—5对钼同多酸以及钨钼杂多酸阴离子的选择

合成了两种氮杂大环八聚多酸超分子配合物［Na（N-Ph）aza-15C5（Et2O）］2Na2MO8O26（Ⅰ）和［Na（N－Ph）aza－15C5（Et2O）］2Na2Wo25Mo7.75O26（Ⅱ），用元素分析、IR、1HNMR和H，H－COSY谱进行了表征，并用X射线测定了配合物（Ⅱ）的晶体结构．配合物（Ⅱ）属单斜晶系，空间群为P21/c，晶胞参数为：a=1.7644（4）nm，b=1．3702（3）nm，c=1．4507（3）nm，β=114．02（3）°，Z=2．该类晶体由大环金属销配位阳离子和二维阴离子网络［Na2WxMo8-xO26」2-组成，阴、阳离子分层堆积．研究了苯基氮杂-15-冠-5和与之键合的多酸阴离子的结构及相互关系．发现在苯基氮杂-15-冠-5分别与八错多酸和六聚钨错杂多酸反应所得的产物中，多酸阴离子的聚合度均为8．表明大环化合物的结构与阴离子的结构有一定的对应关系．