基于异构三联苯-2,2″,4,4″-四羧酸构筑的单水桥钴(Ⅱ)、镍(Ⅱ)配位聚合物的合成、结构及磁性质

Co(Ⅱ)/Ni(Ⅱ) Coordination Polymer of Isomeric Terphenyl-2,2",4,4"-tetracarboxylic Acids with a Single Water Bridge:Syntheses,Structures,and Magnetic Properties

使用异构三联苯-2,2″,4,4″-四羧酸配体(m-H_(4)tpta和p-H_(4)tpta),通过水热法合成了2例新的单水桥Co(Ⅱ)/Ni(Ⅱ)金属链状配位聚合物[Co(m-H_(4)tpta)(H_(2)O)_(3)]_(n)(1)和{[Ni_(2)(p-tpta)(H_(2)O)_(6)]·2H_(2)O}_(n) (2)。其结构通过FT-IR、元素分析、X射线单晶及粉末衍射进行了表征。在结构上,金属离子呈现出轻微扭曲的八面体几何构型,通过单水分子桥连接形成了一维金属链,异构H_(4)tpta配体分别采用μ_(1)-η^(1)∶η^(0)∶η^(1)∶η^(0)和μ_(4)-η^(1)∶η^(1)∶η^(1)∶η^(1)配位模式与金属离子连接,形成一维链和三维网状结构,配合物2表现出(4,4)-连接的NbO型的三维拓扑网络结构。磁性方面,配合物1的Co离子间通过μ_(2)-H_(2)O桥传递表现出反铁磁相互作用。配合物2也展现出Ni离子间的反铁磁耦合作用,与磁耦合Ni—Ow—Ni角有关。

Two single water-bridged Co(Ⅱ)/Ni(Ⅱ) chains coordination polymers,namely [Co(m-H_(2)tpta)(H_(2)O)_(3)]_(n)(1) and{[Ni_(2)(p-tpta)(H_(2)O)_(6)]·2 H_(2)O}_(n)(2) were synthesized based on isomeric terphenyl-2,2 ",4,4"-tetracarboxylic acid(m-H_(4)tpta and p-H_(4)tpta) ligands under hydrothermal conditions.They have been structurally characterized by FT-IR,elemental analysis,single-crystal,and powder X-ray diffraction analysis.Structurally,the central metal ions display slightly distorted octahedral geometries in 1 and 2,and are linked to 1 D metal chains by single bridging water molecules.The isomeric H_(4)tpta ligands coordinate metal ions in different μ_(1)-η^(1)∶η^(0)∶η^(1)∶η^(0)and μ_(4)-η^(1)∶η^(1)∶η^(1)∶η^(1) coordination modes,leading to the formation of 1 D chain and 3 D network structure.Complex 2 displays a 3 D network with(4,4)-connected NbO net topology.Magnetically,complex 1 exhibited an antiferromagnetic interaction through μ_(2)-H_(2)O in the uniform Co(Ⅱ) chain model.Complex 2 also showed an antiferromagnetic coupling between Ni(Ⅱ) ions corresponding to magnetic coupling Ni—Ow—Ni angles.CCDC:1415021,1;1415020,2.