基于多齿有机膦酸配体及草酸的过渡金属Fe、Co、Mn三维微孔结构配合物的设计与磁性研究

发布时间：2018-08-05 14:07

【摘要】：分子基磁体是一个热门的研究方向,目前针对分子基磁性材料的研究主要集中在以下几个方面：多功能磁性材料,如手性、电化学性质、孔性与磁性共存的材料；高临界温度的分子磁体；以及纳米级磁性分子材料等。本论文选择了两种空间几何结构类似且具有相同官能团的有机亚膦酸配体,并结合草酸配体和氰基桥联配体,与过渡金属盐反应,成功合成了八个配位化合物,其中有七个化合物表现出微孔性。探讨了温度、溶剂、pH值等实验条件对配合物合成的影响,详细地研究了这些化合物的相关性质及结构与性质之间的关系。(1)采用两种空间几何结构类似且具有相同官能团的有机亚膦酸配体(H4pbp)和2N(C2H4)2(CH)2(C2H4)2 (H4bbp),在无草酸的条件下,H4pbp分别与FeCl2. CoCl2和Mn(COO)2反应,成功合成了三个晶体结构相同但中心金属不同的配位化合物FeH2pbp·2H2O (1), CoH2pbp·2H2O(2)和MnH2pbp·2H2O (3).在引入草酸的条件下,分别选择氯化亚铁、氯化钴和六氰基钴酸钾作为金属源,成功合成了三个新颖的三维微孔结构的过渡金属配位化合物：[Fe2pbpo.5(C204)1.5H20]·2H20 (4), [Co2(H2pbp)o.5(C204)1.5H20]·2H20 (5)和[Co3(H2bbp)(C2O4)2]·2CH3OH·H20 (6).化合物4和5虽然中心金属不同,但两者具有极其相似的晶体结构,而由于主配体以及有机磷酸配位模式的不同,化合物6呈现出与化合物4和5完全不同的三维微孔结构。对化合物4-6的磁性测试表明,化合物4为反铁磁,化合物5和6为变磁。这种微孔结构在吸附、以及催化等方面都有潜在的应用价值。(2)利用K3[Co(CN)6]作为建筑单元,结合草酸配体,在不同的有机模板剂与溶剂的条件下,成功制备了两个氰基和草酸根协同桥联的金属有机配合物：Na[Co3(CN)6(H20)2(C204)]·H20 (7)和[Co3(CN)6(C2O4)(H2O)]Cl·CH3OH·2H2O (8).化合物7表现出三维框架结构,化合物8表现出三维微孔结构。化合物7的中心金属存在二价钴离子,对其磁性研究表明,存在反铁磁相互作用。化合物8的金属中心均为三价钴离子,因此化合物8是抗磁的。化合物7和8独特且稳定的三维框架结构,可用作电池材料的前驱体。
[Abstract]:Molecular based magnets are a hot research field. At present, the research of molecular based magnetic materials is mainly focused on the following aspects: multifunctional magnetic materials, such as chiral, electrochemical properties, pore and magnetic coexistence; High critical temperature molecular magnets; and nano-scale magnetic molecular materials. In this paper, two kinds of organic phosphite ligands with similar spatial geometry and the same functional groups were selected, and eight coordination compounds were successfully synthesized by the reaction of oxalate ligands and cyano-bridged ligands with transition metal salts. Seven of them showed micropore properties. The effects of experimental conditions such as temperature, pH value of solvent on the synthesis of the complex were discussed. The properties of these compounds were studied in detail. (1) two kinds of organic phosphine acid ligands (H4pbp) and 2N (C2H4) _ 2 (CH) _ 2 (C2H4) _ 2 (H4bbp) were used. Three coordination compounds FeH2pbp 2H2O (1), CoH2pbp 2H2O (2) and MnH2pbp 2H2O (3) were successfully synthesized by CoCl2 and Mn (COO) _ 2 reaction. Three novel transition metal coordination compounds, [Fe2pbpo.5 (C204) 1.5H20] 2H20 (4), [Co2 (H2pbp) o.5 (C204) 1.5H20] 2H20 (5) and [Co3 (H2bbp) (C2O4) 2] 2CH3OH H20 (6), were successfully synthesized by introducing oxalic acid. Although the central metals of compounds 4 and 5 are different, they have very similar crystal structures. Due to the difference of coordination modes of principal ligands and organophosphoric acids, compound 6 exhibits a three-dimensional micropore structure completely different from compounds 4 and 5. The magnetic test of compound 4-6 shows that compound 4 is antiferromagnetic and compounds 5 and 6 are magnetized. This microporous structure has potential applications in adsorption and catalysis. (2) using K3 [Co (CN) 6] as building unit, combining oxalic acid ligands, under different organic templates and solvents, Two organometallic complexes: na [Co3 (CN) 6 (H 20) 2 (C 204)] H 20 (7) and [Co3 (CN) 6 (C2O4) (H 2O)] Cl CH3OH 2H2O (8) were successfully prepared. Compound 7 exhibits a three-dimensional frame structure and compound 8 exhibits a three-dimensional micropore structure. There is a divalent cobalt ion in the central metal of compound 7. The magnetic properties of compound 7 indicate that there is an antiferromagnetic interaction. The metal centers of compound 8 are all trivalent cobalt ions, so compound 8 is diamagnetic. Compounds 7 and 8 have unique and stable three-dimensional frame structures and can be used as precursors for battery materials.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O641.4

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