节点文献
基于Keggin多金属氧酸盐和仲钨酸盐-B的桥连化合物的研究
The Study of the Bridging Compounds Based on Keggin-type and Paratungstate-B
【作者】 原玲;
【导师】 王恩波;
【作者基本信息】 东北师范大学 , 无机化学, 2009, 博士
【摘要】 本论文采用多金属氧酸盐为基本建筑单元,运用分子设计和分子工程思想,通过金属与含氮螯合或线型配体形成的配合物桥连多金属氧酸盐或通过金属直接桥连多金属氧酸盐,构筑了结构可塑、性能优异的新型化合物。研究这些化合物的合成条件及规律,探讨了不同金属阳离子、不同类型的有机配体等对整个结构的影响,并推测新结构的形成、以及新物质结构和性能间的关系。利用水热技术,通过分子间自组装合成了7种新型的以多金属氧酸盐为建筑单元的过渡金属配合物桥连的杂化化合物;利用常规水溶液合成方法,得到了6种新型的金属阳离子桥连的化合物。通过元素分析、IR、XRPD、TG和X-射线单晶衍射对晶体结构进行了表征,对一些化合物的磁学特性、电化学和荧光性质进行了初步研究。1.以[AlW12O40]5-多阴离子簇为基本建筑单元,通过过渡金属配合物的修饰或连接,构筑了4个新颖的过渡金属配合物桥连的杂化化合物: {Ag3(2,2’-bipy)2(4,4’-bipy)2}{Ag(2,2’-bipy)2}{Ag(2,2’-bipy)}[AlW12O40]·H2O (1) [Ag(phen)2]3[Ag(phen)3][AlW12O40]·H5O2 (2) {Co(2,2’-bipy)3}3{Co(H2O)(2,2’-bipy)2[AlW12O40]}2·H2O (3) (H2bpe){Cu(bpe)}{{Cu(bpe)}2[AlW12O40]}·3H2O (4)在水热条件下,我们得到了在常规水溶液中难以合成的{AlW12}这一很少见报道的物种,并可多次重复。这一成果为{AlW12}的合成开辟了一条简单而有效的途径。在探索过程中,我们发现不同的过渡金属,不同几何构型的有机配体,对所得化合物的结构影响巨大。化合物1是拥有银帽的Keggin簇结构,五个银原子具有四种类型的配位几何构型,这种现象在多酸化学中是不常见的。在化合物2中,由三聚银簇扩展形成的三维超分子在多酸体系中也是少有的。Hill等人的最近研究结果表明,将Ag+和多酸结合得到的物种比多酸母体的催化性能更好。因此化合物1和化合物2的成功制备可望在催化领域有重要应用。化合物3的结构特征是三个水分子在邻近的单支撑的{Co(H2O)(2,2’-bipy)2[AlW12O40]}3-阴离子间线型排列,通过弱的氢键的相互作用形成三维超分子网络。化合物4的结构特征是形成了含有矩形遂道的三维超分子网络。2.将混合联吡啶有机配体引入到多钨酸盐中,我们得到了三种新型的过渡金属铜配合物桥连的杂化化合物: {Cu4IICl(2,2’-bipy)4(4,4’-bipy)3(4,4’-Hbipy)2[PMo12O40]}[PMo12O40]2·2H2O (5) {Cu2I(2,2’-bipy)2(4,4’-bipy)}{Cu1.5I(2,2’-bipy)(4,4’-bipy)}2[BW12O40] (6) [Cu2I(2,2’-bipy)2(4,4’-bipy)][Cu1.5I(2,2’-bipy)(4,4’-bipy)]2[H3W12O40] (7)因为混合配体能够在反应中形成不同的过渡金属配合物片段,这些配合物片段与多酸单元的键连能力不同,有利于在不同的方向与多酸表面的氧原子配位形成结构独特的化合物。同时也再次证明了水热合成方法是合成新奇结构材料的有效途径。在化合物5中,通过Cu–Cl键形成了双核铜簇,这种情况在多酸体系中首次被发现,而且化合物5展示了一个独特的多酸作为悬垂体的二维结构,这样的化合物可以展示有效的具有重要应用价值的光致电子转移特性。化合物6拥有一维遂道的三维网络结构。值得一提的是化合物7,根据文献调研,化合物7是首例报道的以同多钨酸盐[H2W12O40]6-为建筑单元和含有混合配体的过渡金属配合物形成的一维链状结构的化合物。3.以同多钨酸盐为基本建筑单元,利用碱金属、碱土金属、不同的过渡金属、稀土金属,通过常规水溶液的合成方法,得到了6种基于同多钨酸盐的修饰或扩展结构的新型化合物。考察了产物的形成条件,配位能力,特别是成功实现了[W10O32]4+→[H2W12O42]10-转化,证实了Pope以前的设想,为同多钨酸盐的某些转化提供了有价值的证据。另外化合物12、13的成功合成为基于仲钨酸盐化合物的合成又提供了一条新的合成路线。[Na8(H2O)28)][Mn(H2O)2(H2W12O42)]·4H2O (8) [Zn5(H2O)20(H2W12O42)]·16H2O (9) K[Na5(H2O)6][Sr2(H2O)6(H2W12O42)]·18H2O (10) (NH4)3[Na5(H2O)17Cl]{[Na(H2O)4]2[CeW10O36]}·6H2O (11) (H3O)3[{K(H2O)}2{Na2(H2O)8}2(Na0.5H2O)2(H2W12O42)]·6H2O (12) (H3O)2[{K(H2O)4}2{Na3(H2O)9}2(H2W12O42)]·2H2O (13)化合物8是由一维的[Mn(H2O)2(H2W12O42]n8-链和钠链[Na8(H2O)28]n8+相互键连形成的二维层状结构。化合物9是由仲钨酸盐阴离子经[Zn4(H2O)14]8+单元的连接形成的含有菱形遂道的二维层结构。在化合物10中,仲钨酸盐扮演着六齿配体和六个Sr离子通过钾和钠离子强烈的相互作用,产生了包含两种类型遂道的三维网络结构。化合物11是首例报道的以[Ce(W5O18)2]9-为建筑单元构筑的扩展结构的化合物。该化合物首先由夹心型的[CeW10O36]9–簇连接双核[Na2(H2O)8]2+单元形成一条直链,然后又通过新型的五核[Na5(H2O)17Cl]4+间氢键的强烈相互作用而形成的二维超分子网络结构。化合物12和化合物13是在不同的反应温度条件下,从十钨酸盐的醋酸钠缓冲溶液中分离出来的仲钨酸盐化合物,它们展示了由不同连接方式的钠和钾作为抗衡阳离子的三维结构。
【Abstract】 In this paper, the aim of this thesis is the synthesis of new framework compounds on the basis of polyoxometalates. The study on synthetic conditions and rules for these new compounds by utilizing metal ions and its organic chelating or linetype N-donor ligands complexes, and the exploration of relationships between structures and properties for these new compounds are also carried out.Seven new transation metal coordination hybrid compounds and six new metal cations bridging compounds have been synthesized on the basis of hydrothermal technique /or regular synthesis methods and structurally characterized by elemental analyses, IR, XRPD, TG and single crystal X-ray diffractions. The thermal stabilities, magnetic properties, Luminescence properties and electrochemical activities of these compounds have been studied.1. Four novel transation metal coordination hybrid compounds have been synthesized through the decoration or connection of transition metal ions based on the [AlW12O40]5- polyanions. {Ag3(2,2’-bipy)2(4,4’-bipy)2}{Ag(2,2’-bipy)2}{Ag(2,2’-bipy)}[AlW12O40]·H2O (1) [Ag(phen)2]3[Ag(phen)3][AlW12O40]·H5O2 (2) {Co(2,2’-bipy)3}3{Co(H2O)(2,2’-bipy)2[AlW12O40]}2·H2O (3) (H2bpe){Cu(bpe)}{{Cu(bpe)}2[AlW12O40]}·3H2O (4)Under the hydrothermal condition, We have obtainded the infrequent {AlW12} species which is difficult to be obtained using the bench method. The results open up a door for the sample and availability synthesis method of the {AlW12} species.In research process, we found that the different transition metal ions and ligands with different configurations would impact the structure of the product as synthesised. The structure of compound 1 possess of silver-capped character. Five crystallographically independent Ag ions have four types of coordination geometry, this is infrequent in polyoxometalates chemistry. The trimeric {[Ag(phen)2]3}3+ cluster in compound 2 are rarely to extend into a three-dimensional supramolecular network. Recently, Hill’s study result shows that the catalysis activity of the extend polyoxometalates decorated and connected by Ag+ ions is better than their matrix polyoxometalates. The successful synthesized of compounds 1 and 2 have shown that they will be significantly useful in catalysis. The structure feature of compound 3 is that three water molecules linearly arrange between the adjacent monosupporting {Co(H2O)(2,2’-bipy)2[AlW12O40]}3- anions, leading to form the resulting three-dimensional supramolecular network by weak interactions. The structure feature of compound 4 is that a 3-D supramolecular network featuring 1-D rectangular channels formed.2. Introducing the mixed bpy ligands into polyoxotungstates, we have obtained three kinds of novel transation metal copper coordination hybrids compounds: {Cu4IICl(2,2’-bipy)4(4,4’-bipy)3(4,4’-Hbipy)2[PMo12O40]}[PMo12O40]2·2H2O (5) {Cu2I(2,2’-bipy)2(4,4’-bipy)}{Cu1.5I(2,2’-bipy)(4,4’-bipy)}2[BW12O40] (6) [Cu2I(2,2’-bipy)2(4,4’-bipy)][Cu1.5I(2,2’-bipy)(4,4’-bipy)]2[H3W12O40] (7)Because mixed organic ligands can form the different transition metal subunit, which have different coordinate ability for different polyoxometals unit, which will result in the novel structure with different coordination enviroment between polyoxometals and transition metal complexes, and demonstrating that the hydrothermal method is the effective for the construction of novel structures.In compound 5, the dinuclear copper unit is formed by means of a Cu–Cl bond. This case is first observed in the POM system and shows a unique 2D architecture with dangling polyoxoanion clusters, such compounds may exhibit efficient photoinduced electron transfer. compound 6 is that the complex containing mixed organoamine ligands exhibits an unusual three-dimensional network. It is noteworthy the compound 2 represents the first 1D structure formed by ispolyoxotungstate building blocks [H2W12O40]6– and transition metal complex frameworks with mixed ligands.3. Six new inorganic compounds with extend structure have been synthesized on the basis of the various metals in the presence of ispolyoxotungstates. The structural transformation [W10O32]4-→[H2W12O42]10- confirmed the previous prediction of Pope and offered a route for the preparation of paratungstate-based compounds. [Na8(H2O)28)][Mn(H2O)2(H2W12O42)]·4H2O (8) [Zn5(H2O)20(H2W12O42)]·16H2O (9) K[Na5(H2O)6][Sr2(H2O)6(H2W12O42)]·18H2O (10) (NH4)3[Na5(H2O)17Cl]{[Na(H2O)4]2[CeW10O36]}·6H2O (11) (H3O)3[{K(H2O)}2{Na2(H2O)8}2(Na0.5H2O)2(H2W12O42)]·6H2O (12) (H3O)2[{K(H2O)4}2{Na3(H2O)9}2(H2W12O42)]·2H2O (13)The 2D layered structure of the compound 8 is formed by the interconnection of 1D [Mn(H2O)2(H2W12O42)]n8- and [Na8(H2O)28]n8+chains. In the compound 9, theparatungstate ions are linked by [Zn4(H2O)14]8+ units, leading to the formation of a 2D layer containing rhombic channels. Compound 10, paratungstate-B units act as six-dentate ligands coordinating to six Sr2+ ions. Interestingly, the strong involvement of the potassium and sodium counteractions leads the neighboring layers to tie together generating a 3D network containing two types of channels. Compound 11 represents the first extended structure based on the [Ce(W5O18)2]9- polyoxoanion. Compounds 12 and 13 were isolated from the acetate buffer solution containing decatungstate [W10O32]4- at different reaction temperatures and exhibit different three-dimensional architectures with bridging sodium and potassium as countercations.
【Key words】 Polyoxometalates; Bridging compounds; Crystal Structure; Properties;