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基于松香酸的金属—有机骨架化合物的合成尧结构与性质的研究
Syntheses, Structures, and Properties of Novel Metal-Organic Frameworks Based on Rosin Acid
【作者】 杨萍;
【导师】 徐莉;
【作者基本信息】 南京林业大学 , 材料学, 2012, 硕士
【摘要】 近年来,由金属离子和有机配体桥联构筑的金属-有机骨架(Metal-OrganicFrameworks,简称MOFs),由于其迷人、多样的拓扑结构及广泛的潜在应用(如催化、气体存储、气体选择性吸附和分离、光学及磁学材料等)而成为功能材料领域的研究热点。到目前为止,人们已获得了大量的MOFs配合物,研究表明,通过适当地选择金属离子和有机配体可以设计得到具有特定拓扑结构及性能的MOFs。芳香多羧酸类配体配位能力强,配位方式灵活,因而常被选作有机配体用于构筑MOFs。以往的配体大多由不可再生的石油原料经过化学合成而得到,而本课题选用天然产物松香为原料,对其进行接枝改性,设计并合成出具有多个羧基配位点的松香基配体。松香树脂酸三环菲骨架的引入,使得松香基配体具有半刚性特点,利用溶剂热法合成得到了三个新颖的MOFs配合物。本课题的研究对拓展松香这一丰富的可再生资源新的应用领域、开发新型精细化工产品、提高科技含量、增加松香深加工产品的出口创汇能力、振兴松脂产业具有重要意义。主要研究内容如下:(1)利用丙烯酸和富马酸对松香进行改性,采用钠盐法进行分离提纯,得到了含量达95%以上的丙烯海松酸和富马海松酸。并通过FT-IR、1H-NMR和熔点测定对丙烯海松酸和富马海松酸进行了结构表征。为制备松香基金属-有机骨架化合物合成了结构新颖的多羧酸配体。(2)以丙烯海松酸(H2LA)(含有二个羧基)为配体和过渡金属盐通过溶剂热法,合成了两个新颖的MOFs配合物{[Cd2(LA)2(DMF)(H2O)0.5]·0.5H2O}n(1)和[Zn3(LA)2(μ3-OH)2]n(2)。通过单晶XRD、粉末XRD、元素分析和红外光谱进行了结构表征。单晶结构分析表明,配合物1是由1D链通过氢键产生的2D层状结构。1D链是由八连接的蝴蝶状的四核Cd(次级构筑单元SBU)通过二连接的二齿羧酸形成的。与以往的四核单元不同,其四核Cd(次级构筑单元SBU)包含三种晶体学独立的Cd(Ⅱ)离子。在配合物1中配体显示出了两种不同的配位模式:(a)每个羧酸根与Cd(Ⅱ)均以螯合-桥式三齿模式配位;(b)一个羧酸根与Cd(Ⅱ)以顺,顺-桥式双齿模式配位,另一个与Cd(Ⅱ)以螯合-桥式三齿模式配位。配合物2是由1D链通过二连接的二齿羧酸产生的2D层状结构。1D链是由四连接的蝴蝶状的四核Zn(次级构筑单元SBU)形成的,具有独特的“Z”型结构。其中四核Zn(次级构筑单元SBU)包含三种晶体学不同的Zn离子。在配合物2中配体的每个羧酸根与Zn(Ⅱ)均以顺,顺-桥式双齿模式配位。热重分析表明,配合物1和2分别在温度达370和373oC骨架才开始坍塌,可见配合物1和2具有很好的热稳定性。固态荧光测试表明,配合物1和2具有中等强度的荧光。(3)以富马海松酸(H3LF)(含有三个羧基)为配体和过渡金属盐通过溶剂热法,得到了一个新颖的MOF配合物{[Cd(H2LF)2(H2O)2]·10H2O}n(3)。通过单晶XRD、粉末XRD、元素分析和红外光谱进行了结构表征。单晶结构分析表明,配合物3是由1D链通过氢键产生的2D层状结构。1D链是由M2(H2LF-)2的大环(次级构筑单元SBU)沿b轴通过Cd(Ⅱ)连接形成的。这些1D链之间存在大量客体水分子,它们之间通过氢键相互作用沿b轴形成了一维水链。在配合物3中,配体的羧基未完全去质子化。其中叔碳所连的羧基未参与配位,另外两个羧基与Cd(Ⅱ)分别以单齿和螯合双齿模式配位。热重分析表明,配合物3在温度达355oC骨架才开始坍塌,可见配合物3具有良好的热稳定性。固态荧光测试表明,配合物3具有中等强度的荧光。
【Abstract】 In recent years, the metal-organic frameworks (Metal-Organic Frameworks,referred to as MOFs) from metal ions and organic ligands became a hot researchfield of functional materials, because of their charming, variety of topology structure,and widely potential applications, such as catalysis, gas storage, selective gasadsorption and separation, optical and magnetic materials. So far, people haveprepared a lot of MOFs. The studies showed that MOFs with specific topologystructures and properties could be designed through choosing appropriate metal ionsand organic ligands.Multi-carboxylic ligands, with the strong coordination ability and flexiblecoordination mode, were often chosen as the organic ligands to build MOFs. Most ofprevious ligands were synthesized from non-renewable petroleum, however, ourrosin-based ligands with multiple carboxyl coordination sites were obtained fromnatural rosins by modification, which possessed semi-rigid structures with tricyclicphenanthrene skeleton. And three novel MOFs based on our rosin acid ligands weresynthesized using solvothermal method. The study may lead to expand rosin newapplication areas, and develop new fine chemical products.The main research contents were as follows:(1) In order to prepare rosin-based MOFs, the acrylpimaric acid andfumaropimaric acid were synthesized, and purified by sodium salt method. Thepurity was more than95%. Their structures were characterized by FT-IR,1H-NMRand melting point determination.(2) Two novel MOFs,{[Cd2(LA)2(DMF)(H2O)0.5]·0.5H2O}n(1) and[Zn3(LA)2(μ3-OH)2]n(2), were successfully prepared by a solvothermal methodusing acrylpimaric acid (H2LA)(containing two carboxyl groups) as the ligand andtransition metal salts. The complexes were characterized with single-crystal X-raycrystallography, powder X-ray diffraction, elemental analysis and FT-IR.Single-crystal structure analysis revealed that complex1was a2D layered structureresulting from intermolecular hydrogen bonding of1D chains.1D chains wereconstructed by the butterfly-shaped tetranuclear Cd(Ⅱ) unit (SUB)(with eightconnection) and the bidentate carboxylic acid (with two connection). Thetetranuclear Cd(Ⅱ) unit contained three crystallographic independent Cd(Ⅱ) ions,different from previously reported four nuclear units. The Ligands in complex1showed two different coordination modes:(a) two carboxylate groups were respectively coordinated to two Cd (Ⅱ) ions in a chelated-bridge tridentatecoordination mode;(b) one carboxylate group was coordinated to two Cd(Ⅱ) ions ina bridging bidentate (syn-syn) coordination mode, the other carboxylate grouplinked with two Cd (Ⅱ) ions in a chelated-bridge tridentate coordination mode.Complex2was a2D layered structure constructed by1D chain connecting with thebidentate carboxylic acid.1D chains were built by the butterfly-shaped tetranuclearZn(Ⅱ) unit (with four connection) with a unique ‘zig-zag’ structure. The tetranuclearZn(Ⅱ) unit contained three crystallographic independent Zn(Ⅱ) ions. In complex2,each carboxylate group in the ligand linked with two Zn(Ⅱ) ions by a bridgingbidentate (syn-syn) coordination mode. TGA showed that the frameworks ofcomplexes1and2began to collapse above the temperature370, and373oC,respectively, which exhibited that complexes1and2had good thermal stabilities.Solid-state fluorescence measurements revealed that complex1and2displayedmedium strong emission peaks.(3) A novel MOF,{[Cd(H2LF)2(H2O)2]·10H2O}n(3), was successfully preparedby a solvothermal method using fumaropimaric acid (H3LF)(containing threecarboxyl groups) as the ligand and transition metal salt. The complex wascharacterized with single-crystal X-ray crystallography, powder X-ray diffraction,elemental analysis and FT-IR. The Single-crystal structure analysis revealed thatcomplex3was a2D layered structure resulting from intermolecular hydrogenbonding of1D chains.1D chains were constructed by M2(H2LF-)2macrocyclic (SUB)connected each other via Cd(Ⅱ) along the b axis. Specifically, there were a largenumber of water molecules between the1D chains. These water molecules formedone dimensional water chains along the b axis through hydrogen bonding. Incomplex3, the carboxyl groups of the ligand were not fully deprotonated. Thecarboxyl group connected with tertiary carbon atom was not coordinated with Cd(Ⅱ),the other two carboxyl groups coordinated to Cd(Ⅱ) ions in monodentate andchelating bidentate coordination modes, respectively. TGA showed that theframework of complex3began to collapse above the temperature of355oC, had goodthermal stability. The solid-state fluorescence measurements showed that thecomplex3displayed medium strong emission peak.
【Key words】 Rosin acid; Metal-organic frameworks (MOFs); Crystal structure; Fluorescence;
- 【网络出版投稿人】 南京林业大学 【网络出版年期】2012年 11期
- 【分类号】O621.2
- 【被引频次】1
- 【下载频次】127