不同维数铕（Ⅲ）配合物的可控合成、结构及荧光性质

【作者】 姜菲；

【导师】 周云山； 张立娟；

【作者基本信息】 北京化工大学 ， 应用化学， 2009， 硕士

【摘要】 稀土配合物由于多变而迷人的拓扑结构日益受到人们的关注,在荧光材料、催化领域以及非线性光学材料等领域均有广泛的应用前景。Eu（Ⅲ）离子由于具有荧光强度高、荧光寿命长及发射谱带尖锐等特点更成为研究中的热点。当选择合适的有机配体与Eu（Ⅲ）离子形成配合物时,不但可以构筑结构新颖的配合物,而且可以由配体向Eu（Ⅲ）离子进行有效的能量传递,得到性能优良的发光材料。本论文选择5-（2′-吡啶）四唑、N-氧化烟酸、2,2′-联吡啶-3,3′二羧酸和草酸为配体,以Eu（Ⅲ）离子为中心离子,合成了四个具有不同结构和维数的新型铕配合物,并对它们进行了元素分析、红外和热重分析表征,解析了其单晶结构并研究了它们在室温条件下的固体荧光性质。同时考察了包括第二配体用量、金属离子的引入等因素对于配合物可控合成及结构的影响。1.对配体5-（2′-吡啶）四唑的合成工艺进行优化,得到了合成5-（2′-吡啶）四唑的最佳反应条件为:n_叠氮化钠:n_{2-氰基吡啶}:n_三乙胺=1.05:1:1.15,反应时间是12小时,5-（2′-吡啶）四唑产率可达78.1%。利用合成的5-（2′-吡啶）四唑作为配体,选择Eu（Ⅲ）离子作为中心离子,得到了配合物[Eu（C₆H₄N₅）₃（H₂O）₃]（H₂O）_3.5（1）,配合物1为零维结构,相邻的Eu（Ⅲ）离子通过配位水和晶格水的氢键作用,形成由Eu-O-Eu水链连接成的二维层状结构,同时配合物1具有良好的荧光性质。2.利用N-氧化烟酸为第一配体,草酸作为第二配体,在水热条件下合成了两个结构不同的铕（Ⅲ）配合物[Eu₂（NNO）₄（COO）₂（H₂O）₂]（2）和Eu₂（NNO）₄（OOC-COO）（H₂O）₂（3）（HNNO=N-氧化烟酸,HOOC-COOH=草酸）。配合物2中Eu（Ⅲ）离子展示了一种畸变的五配位的几何构型,NNO配体通过采取双连接方式将相邻的Eu（Ⅲ）离子连接形成一维无限链,相邻的一维无限链进一步通过氢键作用形成了二维网状超分子结构。配合物3则首先通过配体NNO采取三连接方式将相邻的双核Eu（Ⅲ）离子连接成一维多孔双链,相邻的一维双链进一步通过NNO配体采取双连接方式与Eu（Ⅲ）离子配位连接成二维网状结构,每一个二维层由采取双连接方式的草酸根与Eu（Ⅲ）离子配位形成三维孔道状拓扑结构。荧光光谱显示配合物3的荧光强度高于配合物2,进一步证明了结构对性质的影响。同时,第二配体的用量和金属离子的引入因素对配合物单晶体的生成和结构起到一定的调控作用。3.以2,2′-联吡啶-3,3′二羧酸为有机配体,在水热条件下与Eu（Ⅲ）离子和Ag（Ⅰ）离子作用得到了结构新颖的高维数异核配合物[Eu₄Ag₂(C₁₂H₆O₄N₂)₅（OH）₄（H₂O）₃·10H₂O（4）。配体2,2′-联吡啶-3,3′二羧酸在配合物4中展现出五种不同的配位模式,关于该配体在同一化合物中存在五种配位模式目前还未见文献报道,其中发现2,2′-联吡啶-3,3′二羧酸四种新型配位方式,配合物4展现出良好的荧光特性。此外,反应原料配比、反应时间等因素对配合物单晶体的生成及配合物的结构具有一定的控制性。当反应原料中2,2′-联吡啶-3,3′二羧酸和Eu₂O₃的摩尔数分别固定为1mmol和0.5mmol,AgNO₃的摩尔数等于或是大于0.4mmol时,得到没有荧光的浅黄色微米管。更多还原

【Abstract】 Considerable attentions have been paid to the rational design and synthesis of rare earth complexes in recent years,not only due to their intriguing variety of architectures and topologies but also for their potential applications as functional materials such as luminescence,catalysis and nonlinear optics.The fluorescence of Eu（Ⅲ） ion is well studied due to its intense,long lived excited states,its emission at long wavelengths with line-like emission bands and distinguishable long lifetimes.The appropriate ligands not only can construct the complex with novel structure,but also cause the energy transfer from ligands to Eu（Ⅲ） ion,resulting in good fluorescent materials.5-（2’-pyridyl）tetrazole,nicotinic acid N-oxide,2,2’-bipyridyl-3, 3’-dicarboxylic acid and oxalic acid are selected as the ligands,Eu（Ⅲ） ion and Ag（Ⅰ） ion as center ions to design and synthesize four novel rare earth complexes with different structures.Characterizations for complexes 1-4 by single crystal X-ray diffraction,IR,elemental analysis,thermal analysis and fluorescence have also been described.Furthermore,we also discuss how the dimensionality of the resulting coordination frameworks and fluorescence of Europium（Ⅲ） complexes can be manipulated by the factors of dosage of the second ligand or adding the other metal ion.1.The optimization of synthesis condition of 5-（2’-pyridyl）tetrazole is that the molar ratio of NaN₃:2-cyanopyridine:triethylamine is 1.05:1:1.15,the reaction time is 12h,and yield of 5-（2’-pyridyl）tetrazole is increased to 78.1% based on 2-cyanopyridine.Besides,[Eu（C₆H₄N₅）₃（H₂O）₃]（H₂O）_3.5（1） was prepared with 5-（2’-pyridyl）tetrazole.In complex 1,Eu（Ⅲ） ions are linked together by hydrogen bond to form two-demensional network structure.The complex 1 exhibits great characteristic emission of Eu（Ⅲ） ion.2.N-oxide nicotinic acid and oxalic acid are selected as the first ligand and the second ligand,respectively,and two Europium（Ⅲ） complexes[Eu₂ （NNO）₄（COO）₂（H₂O）₂]（2） and Eu₂（NNO）₄（OOC-COO）（H₂O）₂（3）（HNNO= nicotinic acid N-oxide,HOOC-COOH= oxalic acid） were synthesized under hydrothermal condition.In complex 2,the Eu（Ⅲ） ions are linked together by carboxyl groups of NNO ligands to form an infinite one-dimensional chain, which further construct the two-dimensional supramolecular network structure with hydrogen bond.Complex 3 holds three-dimensional topological structure linked by nicotinic acid N-oxide and oxalic acid.The complex 3 exhibits great characteristic emission of Eu（Ⅲ） ion,which is stronger than complex 2. Furthermore,the factors of dosage of the second ligand or adding the metal ion are discussed aiming at finding out the influence in structures of complexes.3.Europium（Ⅲ） complex[Eu₄Ag₂(C₁₂H₆O₄N₂)₅（OH）₄（H₂O_）3]·10H₂O（4） was synthesized by 2,2’-bipyridyl-3,3’-dicarboxylic acid under hydrothermal condition with Eu₂O₃ and AgNO₃,which possess an novel three-dimensional structure.The 2,2’-bipyridyl-3,3’-dicarboxylic acid shows five coordination modes in the complex,which is rare in rare earth complex reported. Furthermore,four new coordination modes are shown in the paper.Complex 4 exhibits great characteristic emission of Eu（Ⅲ） ion.Besides,we also discuss the factors of mole ratio of reactants,the reaction temperature and time to determinate the optimum conditions for the resulting structure of complex 4. Meanwhile,microtube was obtained when the molar of AgNO₃ is more than 0.4 mmol.更多还原