Synthesesion Pol,Structures And Properties Of Coordinatymers Constructed From Organic Ligand Containing Nitrogen And Carboxyl Group

As a new type of molecule function materials, metal coordinationpolymers（MCPs） have great potential application in magnetism, optics, adsorption,catalysis, ferroelectric, and so on. The function coordination polymers based onnitrogen and/or carboxylic acid ligands has become one of the most attractiveresearch subjects. According to the principle of crystal engineering, it is possible torational design and synthesis of MCPs crystalline materials with predeterminedstructure. At the same time, MCPs can be endowed with different function byselection functional metal ions and organic ligands with functional groups.In this thesis, we focused our study on the synthesis, structures andmultifunctional properties of the MCPs based on nitrogen and/or carboxylic acidligands with different types. Twenty-four new polymers have been successfullyprepared under hydrothermal（solvothermal） conditions and characterized by singlecrystal X-ray diffraction analysis. Besides, we discussed the rules and relationsbetween the structures and properties of some complexes. The main contents can bedivided into following parts:Firstly, the magnetic property of the MCPs is one of the key in this thesis.15complexes were synthesized and characterized based on this purpose. The magneticproperties of complexes1-3and6-11were analyzed in detail. We distribute them intoChapter two and three according the organic ligands. Considering the variousbridging modes and excellent magnetic transmission ability of N3-and COO-, and thereported examples usually containing only one type chemical bridge, we designed andsynthesized three complexes containing both N3-and COO-bridges. All of themdisplay ferromagnetic behavior. Besides, feeble frequency-dependent phenomena ofthe out-of-phase were observed at low temperature for complexes1and2. In Chapterthree, we reported complexes5-15which obtained by3-Aminopyrazine-2-carboxylicacid （apzc） and different lanthanum and transition metal ions under hydrothermalconditions. Single-crystal X-ray analysis revealed that complexes5-11areisostructural, all of them are two-dimensional networks and contain dinuclear units Ln₂O₂, however, they display completely different magnetic behaviors. We focusedon the magnetic properties of complexes8·Tb,9·Dy and10·Ho. Among them,complex9displaying ferromagnetic coupling and slow magnetic relaxation with。=9.47×10-7s and Ueff/kB=73.7K, and presenting the first2D array of lanthanon singlemolecule magnet （SMM）. In addition, we found that the ligand apzc has the strongestcoordination ability with CuIIion compared to other transition metal ions.Secondly, in the aspects of building polymers with novel topologies, we put ourattention into two directions:（i） Based on the existing literature, complexes16-18were synthesized through [2+3] cycloaddition reactions of azide and nitriles in thepresence of Lewis acid such as zinc salt. Complex16possesses a rarenoninterpenetrated （3,6）-connected cationic framework, with big one-dimensional（1D） rhombic channels （14.97×9.46）, which has potential application in gasadsorption. The overall structure motif of complexes17and18show pillared layeredframeworks and feature an scarce3-nodal network with （3,5,6）-connectivity.Furthermore, the solid fluorescent properties and TGA were studied, see Chapter four.（ii） Complexes19-21were synthesized by the reaction of novel ligand H3Abt（Azobenzene-3,5,4’-tricarboxylic acid） and transition metal ions. The structures wereexpanded to three-dimensional supermolecule by different types of hydrogen-bonding,which were formed by water molecule and oxygen of carboxylate. Research indicatedthat the ligand H3Abt shows different coordinate modes when reacting with differentmetal ions. This is very significant for instructing how to design and synthesize targetcomplexes, see Chapter five.Lastly, in the aspect of investigating material with multiferroic properties, wesynthesized three complexes （22-24） with acentric and polar space groups bydifferent chiral ligands and transition metal ions. Their ferromagnetic andferroelectric behaviors were studied in detail. This work afforded some examples ofcompounds with multiferroic properties, which is still very rare so far.In summary, this thesis expounded the synthesis conditions, topologies,magnetism, fluorescence and ferroelectric properties of above-mentioned complexes.We believe that the rules summarized through these basic researches would affordacademic and experiment bases for directing the synthesis of novel architectures.