Construction And Luminescent/Magnetic Properties Of Metal-Organic Frameworks With Triazole-Dicarboxylic Acid

Metal-organic frameworks (MOFs) have drawn extensive attention due to theirpotential applications in gas storage and separation, luminescent materials andmagnetic materials. However, rational design and synthesis of such functionalmolecular materials with controllable structures and properties are still a greatchallenge because the self-assembly of MOFs can be influenced by many factorswhich make it difficult to precisely control the structures of the final products.In this thesis,1H-1,2,3-triazole-4,5-dicarboxylic acid was selected as the mainorganic ligand. Twenty-eight MOFs have been successfully synthesized via a mixedligand approach by selecting metal centers and controlling the reaction conditions andcharacterized by single crystal X-ray diffraction, EA, IR, TG, PXRD, luminescent andmagnetic susceptibility. The main contributions of this thesis are as follows:1. Nine MOFs have been assembled with transition metal ions, involving sixCoII-based magnetic MOFs (1-6) and three ZnII/CdII-based fluorescent MOFs (7-9).Among these CoII-based magnetic MOFs, three pillared-layer homospin CoIImolecular magnets have been obtained, exhibiting rare Néel N-type ferrimagneticbehavior and metamagnetic behaviors with spin canting effects, respectively. Whereasother three MOFs based on cubic cages show antiferromagnetic interactions betweenCo2+ions. The result indicates the topological structures of MOFs can be well tunedby the type of bases used, reaction temperature and solvent, resulting in the expectedproperties. The luminescent properties of ZnII/CdII-based MOFs have been measured.Additionally, a systematic study of the ZnII/CdII-based MOFs implies the topologicalstructures of MOFs and the size of the pore can be greatly influenced by the types ofligands and their size.2. Five isostructural MOFs (10-14) have been assembled with lanthanide metalions showing one-dimensional distorted tube-like channels. Systematic magneticproperties of these isostructural Ln-MOFs have been studied.3. Three series of heterometallic MOFs have been assembled with transitionmetal ions and lanthanide metal ions, involving five Cu-Ln heterometallic MOFs (15-19), four Co-Ln heterometallic MOFs (20-23) and five Zn-Ln heterometallicMOFs (24-28). Systematic magnetic properties of Cu-Ln and Co-Ln heterometallicMOFs have been investigated whereas the acid-base resistance and luminescentproperties of Zn-Ln heterometallic MOFs have been measured．...