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氮杂环配体配合物以及还原态钼磷氧酸盐的合成、结构与性质研究

Studies on the Synthesis, Structures and Characterization of Complexes with N-heterocyclic Ligands and Reduced Molybdenum Phosphates

【作者】 曹敏纳

【导师】 胡宗球;

【作者基本信息】 华中师范大学 , 无机化学, 2008, 硕士

【摘要】 过渡金属与含N、含O类有机配体自组装所形成的配合物以其多样的结构和独特的物理化学性能受到众多无机和有机化学家的关注,成为当前超分子化学和晶体工程的研究热点。此类配合物在分子自组装、分子识别、分子催化、磁性、导电性、离子交换与分离等领域有广泛的应用前景。而多金属氧酸盐(POM)是一类结构独特、性质多样的无机簇状化合物,它在工业催化剂、药学、材料科学等领域中有重要的应用价值。将有机分子与POM结合不仅可集有机分子的可设计性与无机分子的稳定性于一体,而且可派生出许多新的特性成为有机-无机分子杂化材料。在本论文中,根据晶体学以及自组装原理,合成了未见报道、结构新颖的四个配合物,[Ni(pda)2][Ni(phen)3]·11.5H2O(1),[Cu(H2biim)(pda)(H2O)]·H2O(2),[Zn2(H2biim)(HPO42]n(3),[Cd(H2biim)3]n·CO3(4),以及两个还原态钼磷氧酸盐Zn[Mo6O15(PO44]2{[Zn(phen)(H2O)2]2[Zn(phen)(H2O)]2)2·18H2O(5),Cd[K2Mo6O15(PO44]2{[Cd(H2O)3]2[Cd(HOOCNHCOO)(H2O)]2}2·2H2O(6),并通过元素分析、红外、X射线单晶分析进行表征。通过热分析方法研究了1,5,6的热稳定性;并研究了1-6的光发射性质。主要研究结果如下:1、配合物1,2,4的中心离子Ni(Ⅱ)、Cd(Ⅱ)、Cu(Ⅱ)具有八配位的变形八面体构型;配合物3的中心离子Zn(Ⅱ)是四配位四面体构型。配体主要以双齿螯合或双齿桥联的形式参与配位。配体不同的配位方式以及氢键的形成使得配合物具有不同的空间结构。配合物1通过2,6-吡啶二甲酸的螯合配位模式并以其羧基氧与晶格水分子之间的氢键作用形成三维网络结构;配合物2通过两个配体以及晶格水之间的氢键形成二维平面结构;配合物3则通过磷酸氢根与配体N原子上的氢形成氢键并连接成三维网络结构;配合物4通过外界阴离子碳酸根的氧原子与配体氮原子之间的氢键作用形成三维网络结构。2、还原态钼磷氧酸盐5、6分别是在由d10金属Zn、Cd与{Mo6P4O31}簇构成二聚体M{Mo6P4O31}2的基础上形成的三维超分子。3、化合物热分析研究表明,化合物1,5,6具有较好的热稳定性,失去结晶水和配位水后只有部分配体分解,而5、6在高温下依旧保持M{Mo6P4O31}2骨架。4、配合物1-4固态的光发射性质研究表明,金属离子与配体配位后使得配体的荧光发射波长具有一定红移;5和6在长波区域也有光发射现象,说明在M{Mo6P4O31}2骨架内部存在着由端基氧到钼的电子转移。

【Abstract】 The coordination compounds, self-assemble by transition metal ions and ligands containing nitrogen and oxygen atoms, are attracting more attention for their interesting novel structures and properties. The design and synthesis of novel coordination compounds are of important current interest in supramolecular chemistry and crystal engineering. The potentially applications of these compounds will be intensive in the field of molecular self-assemble, molecular recognition, molecular catalysis, magnetism, electrical conductivity, ion exchange and separation etc.While, Polyoxometalates (POM) possess good redox properties and structural versatility and have been widely applied in many fields such as catalysis, medicine, and materials sciences. Recently, POMs incorporated with various organic moieties have received increasing attention, because such novel functional hybrid molecules exhibit some interesting properties.In this thesis, according to the principle of crystal engineering and self-assembly, four coordination complexes, [Ni(pda)2][Ni(phen)3]·11.5H2O (1), [Cu(H2biim)(pda)(H2O)]·H2O (2), [Zn2(H2biim)(HPO42]n (3), [Cd(H2biim)3]n·CO3 (4), and two reduced molybdenum phosphates Zn[Mo6O15(PO44]2{[Zn(phen)(H2O)2]2[Zn(ph en)(H2O)]2}2·18H2O(5),Cd[K2Mo6O15(PO44]2{[Cd(H2O)3]2[Cd(HOOCNHCOO)(H2O)]2 }2·2H2O(6), which are never reporterd and with novel structures and properties, are synthesized and characterized by means of elemental analyses, IR, X-ray single crystal diffraction. The thermal stability of compounds 1,5,6 were analysized by the TG and DSC, and the fluorescent properties were studied for compounds 1-6. The main results are as following:1. The central metal atoms, Ni(Ⅱ)、Cd(Ⅱ)、Cu(Ⅱ), of compound 1,2,4 have a distored octahedronal geometry. Zn(Ⅱ) in compound 3 is a four coordianted and with a tetrahedron geometry. The coordination modes of the ligands within these compounds were mostly chelating bidentate and bridging bidnetate to forms various structures along with hbond. Compound 1 form 3D structure via chelating bidentate coordination mode of 2,6-pyridinedicarboxylic acid and hbond between lattic water molecules and the ligands. Compound 2 forms 2D structure via two ligands and lattic water molecules. Both compound 3 and 4 form 3D structure via N-H...O formed by hydrogen phosphate or carbonate and the ligand. 2. Reduced molybdenum phosphates 5,6 were supramolecules formed on the basis of [M{Mo6P4O31}2] dimer(M=Zn, Cd).3. The results of thermal analyses for the compounds show that compounds 1,5,6 have a good thermal stability, After lose crystallized water and coordinated water ,there are only a few part of ligands have been decomposed, while 5 and 6 maintain the basic framework of M{Mo6P4O31}2.4. The fluorescent emission bands of compound 1-6 at the solid state show that there is no remarkable influence for ligands after coordinated. 5,6 have emission in area of long wavelength indicate there have electrons transfer within M{Mo6P4O31}2 framework.

  • 【分类号】O641.4
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