节点文献
稀土卤代苯甲酸与邻菲啰啉配合物的合成、晶体结构及热化学性质的研究
Preparation, Structure, Thermal Chemical Properties of Lanthanide Complexes with Halogen-Benzoic Acid and 1,10-Phenanthroline
【作者】 王娟芬；
【导师】 张建军；
【作者基本信息】 河北师范大学 ， 无机化学， 2011， 硕士
【摘要】 为了促进芳香羧酸类稀土配合物的应用,本文采用常规室温溶液沉淀法合成了以苯甲酸及5种卤代苯甲酸为酸配体,以含氮配体1,10-邻菲啰啉为中性配体的23种稀土配合物,它们分别为:[Ho（BA）3phen]2, [Ln（2,3-DClBA）3phen]2, [Ln（2-Cl-4-FBA）3phen]2 （Ln =Nd, Sm, Eu, Tb, Dy, Ho）, [Ln（2,5-DClBA）3phen]2, （Ln = Sm, Eu, Tb, Dy, Ho）, [Ln（5-Cl-2-MOBA）3phen]2 （Ln =Nd, Sm, Eu, Ho）, [Sm（2-Cl-4,5-DFBA）3（phen）（H2O）]2。采用EDTA配位滴定法和元素分析仪确定了配合物中金属Ln3+离子以及C、H、N原子的含量,对配合物进行了初步的表征。并用摩尔电导、红外、紫外、荧光光谱、X-射线粉末衍射和热分析等手段对配合物进行了表征及性质研究。用X-射线单晶衍射分析方法获得6种配合物的晶体结构,分别是: [Nd（2-Cl-4-FBA）3phen]2, [Sm（2,5-DClBA）3phen]2, [Tb（2,5-DClBA）3phen]2, [Sm（5-Cl-2-MOBA）3phen]2, [Sm（2-Cl-4,5-DFBA）3（phen）（H2O）]2, [Ho（BA）3phen]2,测试结果表明,它们均以二聚体的形式存在,晶体结构均属于三斜晶系,pī空间群。羧基基团与金属Ln3+离子的配位模式有单齿、双齿螯合、桥联双齿、桥联螯合三齿配位四种。其中晶体[Ho（BA）3phen]2的中心Ho3+离子的空间几何构型为8配位的四方反棱柱;[Nd（2-Cl-4-FBA）3phen]2具有两种同分异构体,配位数为9,中心离子Nd3+的配位空间几何构型也有两种,分别为畸变的九配位的单帽四方反棱柱与三帽三棱柱;其余四种配合物的配位数均为9,所对应的中心离子的空间几何构型为畸变的单帽四方反棱柱。根据TG-DTG的实验结果及分解最终产物的红外分析结果,研究了配合物的热稳定性及热分解过程。采用非线性等转化率积分法,Madhusudanan-Krishnan-Ninan方法和Malek法研究了配合物[Ho（BA）3phen]2第二步与[Sm（5-Cl-2-MOBA）3phen]2第一步热分解过程的非等温动力学,确定了相应热分解过程的机理函数、反应动力学参数（活化能E与指前因子A）以及峰温处的热力学参数（ΔG≠,ΔH≠和ΔS≠）。利用DSC技术根据间接法（比热比较法）的原理测试了7种配合物[Ho（BA）3phen]2, [Ln（2,3-DClBA）3phen]2, [Ln（2-Cl-4-FBA）3phen]2 （Ln = Eu, Tb, Ho）的连续比热值及相对于标准参考温度298.15 K时的热力学函数值(HT-H298.15 K), (ST-S298.15 K)与(GT-G298.15 K)。利用同步热分析仪与红外光谱联用技术（TG/DSC-FTIR）研究了10种配合物[Ho（BA）3phen]2, [Ln（2,5-DClBA）3phen]2, （Ln = Sm, Eu, Tb, Dy, Ho）, [Ln（5-Cl-2-MOBA）3phen]2, （Ln =Nd, Eu, Ho）, [Sm （2-Cl-4,5-DFBA）3（phen）（H2O）]2热分解过程中逸出气体的红外光谱。并通过非线性等转化率积分法计算了三种配合物[Sm（2,5-DClBA）3phen]2, [Tb（2,5-DClBA）3phen]2与[Sm（2-Cl-4,5-DFBA）3（phen）（H2O）]2的热分解反应的活化能E。
【Abstract】 In order to promote the application of the rare earth aromatic carboxylic acid complexes, we have synthesized twenty-three rare earth ternary complexes at room temperature by a solution-precipitation method, in which benzoic acid or halogen-benzoic acid were used as the acid ligand, and 1,10-phenanthroline as the neutral ligand. They are [Ho（BA）3phen]2, [Ln（2,3-DClBA）3phen]2, [Ln（2-Cl-4-FBA）3phen]2 （Ln =Nd, Sm, Eu, Tb, Dy, Ho）, [Ln（2,5-DClBA）3phen]2, （Ln = Sm, Eu, Tb, Dy, Ho）, [Ln（5-Cl-2-MOBA）3phen]2 （Ln =Nd, Sm, Eu, Ho） and [Sm （2-Cl-4,5-DFBA）3（phen）（H2O）]2.The metal Ln3+ contents in the complexes were assayed using an EDTA titration method and the contents of C, H, and N were determined by element analyzer. The complexes were characterized and studied by molar conductance, infrared, ultraviolet, fluorescence spectroscopy, X-ray powder diffraction, thermal analysis and so on.The structures of six ternary complexes of [Nd（2-Cl-4-FBA）3phen]2, [Sm（2,5-DClBA）3phen]2, [Tb（2,5-DClBA）3phen]2, [Sm（5-Cl-2-MOBA）3phen]2, [Sm （2-Cl-4,5-DFBA）3（phen）（H2O）]2 and [Ho（BA）3phen]2 have been determined by X-ray single crystal diffraction. The results show that they are all binuclear molecular and crystallize in triclinic, space group pī. Carboxylate groups coordinated to metal Ln3+ ions present four kinds of coordination modes: unidentate, chelating bidentate, bridging bidentate and bridging-chelating tridentate. For the complex [Ho（BA）3phen]2, the coordination geometry of the center ion Ho3+ is eight-coordinated square antiprismatic conformation. The complex [Nd（2-Cl-4-FBA）3phen]2 has two types of binuclear molecules in its crystal and the coordination geometries of the corresponding center ion Nd3+ is a distorted nine-coordinated monocapped square antiprismatic or a distorted tricapped triangular prism comformation, respectively. For the others four complexes, the center ions are all nine coordination and the coordination geometries are distorted nine-coordinated monocapped square antiprismatic comformations.The thermostability and the thermal decomposition processes of the complexes are discussed by TG-DTG and IR techniques. The integral isoconversional non-linear method, Madhusudanan-Krishnan-Ninan method and Malek method are employed to investigate the kinetics of the second thermal decomposition process of [Ho（BA）3phen]2 and the first thermal decomposition process of [Sm（5-Cl-2-MOBA）3phen]2. The corresponding kinetic parameters （activation energy E and pre-exponential A） and the thermodynamic parameters （ΔG≠,ΔH≠andΔS≠） are also calculated.The continuous heat capacities of the seven complexes [Ho（BA）3phen]2, [Ln（2,3-DClBA）3phen]2, [Ln（2-Cl-4-FBA）3phen]2 （Ln = Eu, Tb, Ho） were measured by DSC technology using indirect measurement method （specific heat comparison method）. In addition, the thermodynamic parameters, enthalpy (HT-H298.15 K), entropy (ST-S298.15 K) and Gibbs free energy (GT-G298.15 K) of the complexes relative to the standard reference temperature 298.15 K were also calculated.The thermal decomposition behaviors and the evolved gases of ten complexes [Ho（BA）3phen]2, [Ln（2,5-DClBA）3phen]2, （Ln = Sm, Eu, Tb, Dy, Ho）, [Ln（5-Cl-2-MOBA）3phen]2, （Ln =Nd, Eu, Ho） and [Sm （2-Cl-4,5-DFBA）3（phen）（H2O）]2 have been discussed by simultaneous TG/DSC-FTIR technique. The activation energy E of the decomposition steps for the complexes [Sm（2,5-DClBA）3phen]2, [Tb（2,5-DClBA）3phen]2 and [Sm （2-Cl-4,5-DFBA）3（phen）（H2O）]2 are calculated by the integral isoconversional non-linear method.
【Key words】 Rare-earth complexes； halogen-benzoic acid； crystal structure； thermal decomposition； non-isothermal kinetics； thermodynamic Functions；