2,4,6-三甲基苯甲酸与5,5'-二甲基-2,2'-联吡啶构筑的系列镧系超分子配合物的晶体结构、热分解机理和性能  

Crystal Structure,Thermal Decomposition Mechanism and Properties of Lanthanide Supramolecular Complexes Based on 2,4,6-Trimethylbenzoic Acid and 5,5'-Dimethyl-2,2'-bipyridine

作　　者：周孟雪 任宁 张建军 Mengxue Zhou;Ning Ren;Jianjun Zhang(Testing and Analysis Center,Hebei Normal University,Shijiazhuang 050024,China;College of Chemistry&Material Science,Hebei Normal University,Shijiazhuang 050024,China;College of Chemical Engineering&Material,Hebei Key Laboratory of Heterocyclic Compounds,Handan University,Handan 056005,Hebei Province,China)

机构地区：[1]河北师范大学分析测试中心,石家庄050024 [2]河北师范大学化学与材料科学学院,石家庄050024 [3]邯郸学院,化学化工与材料学院,河北省杂环化合物重点实验室,河北邯郸056005

出　　处：《物理化学学报》2021年第10期23-32,共10页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21803016)资助项目。

摘　　要：利用2,4,6-三甲基苯甲酸和5,5ʹ-二甲基-2,2ʹ-联吡啶配体在溶剂热的条件下成功合成出系列三元稀土超分子配合物[Ln(2,4,6-TMBA)3(5,5ʹ-DM-2,2ʹ-bipy)]2(Ln=Pr 1,Nd 2,Sm 3,Eu 4,Gd 5,Dy 6),并对其进行了单晶X-射线衍射、元素分析、热重分析等一系列表征。研究结果表明配合物1-5同构,中心离子的配位数为9,配合物通过π–π堆积作用形成一维、二维的超分子结构。配合物6具有不同的结构,中心镝离子的配位数为8,分子间通过π–π堆积作用和C-H…O氢键形成一维、二维的超分子结构。利用TG/FTIR技术研究了配合物的热稳定性和热分解机理,荧光光谱表明配合物4可以发射出Eu^(3+)离子的特征荧光,同时对配合物6的磁性进行了初步探究。Six ternary lanthanide complexes formulated as[Ln(2,4,6-TMBA)3(5,5ʹ-DM-2,2ʹ-bipy)]2(Ln=Pr 1,Nd 2,Sm 3,Eu 4,Gd 5,Dy 6;2,4,6-TMBA=2,4,6-trimethylbenzoate;5,5ʹ-DM-2,2ʹ-bipy=5,5ʹ-dimethyl-2,2ʹ-bipyridine)have been synthesized under solvothermal conditions and characterized by singlecrystal X-ray diffraction,elemental analysis,thermogravimetric analysis,etc.The results of crystal diffraction analysis show that complexes 1–6 are binuclear units,crystallizing in the triclinic Pīspace group.Complexes 1–5 are isostructural,and each of the central metal ions has a coordination number of 9.The asymmetric unit of complexes 1–5 consists of one Ln^(3+),one 5,5ʹ-DM-2,2ʹ-bipy ligand,and three 2,4,6-TMBA−moieties with three coordination modes:chelation bidentate,bridging bidentate,and bridging tridentate.The coordination geometry of Ln^(3+)is distorted monocapped square antiprismatic.The binuclear units of complexes 1–5 form a one-dimensional(1D)supramolecular chain along the c-axis via π–π stacking interactions between the 2,4,6-trimethylbenzoic acid rings.The 1D chains are linked to form a supramolecular two-dimensional(2D)sheet in the bc plane via π–π stacking interactions between the pyridine rings.Although the molecular formulae of complex 6 and complexes 1–5 are similar,the coordination environment of the lanthanide ions is different in the two cases.The asymmetric unit of complex 6 contains a Dy^(3+)ion coordinated by a bidentate 5,5ʹ-DM-2,2ʹ-bipy and three 2,4,6-TMBA−ligands adopting bidentate and bridging bidentate coordination modes.The Dy^(3+)metal center has a coordination number of 8,with distorted square antiprismatic molecular geometry.The binuclear molecule of 6 is assembled into a six-nuclear unit by π–π weak staking interactions between two 5,5ʹ-DM-2,2ʹ-bipy ligands;then,adjacent six-nuclear units form a 1D chain via offset π–π interactions between 5,5ʹ-DM-2,2ʹ-bipy ligands on different adjacent units.The adjacent 1D chains are linked by C―H…O hydrogen bonding int

关 键 词：镧系超分子配合物 晶体结构 热分析 荧光光谱 2 4 6-三甲基苯甲酸 

分 类 号：O642[理学—物理化学]