Syntheses, Structures And Properties Of The Coordination Polymers Based On The Isocyanuric Polycarboxylic Acids

In recent years, studying flexible carboxylic acid coordination polymers has drawn broadattention and became quite hot in research of complexes. Isocyanuric acid ligands are representatives of the flexible carboxylic acid ligands because of their diversities, providing a varietyof configuration coordination patterns and rich novel topologies. Therefore these ligands havearoused great interest of scientists and researchers. The project being reported selected two flexible isocyanuric acid ligands which are tris(2-cyanboxyethyl)isocyanurate (H3tci) and bis(2-cyanboxyethyl)isocyanurate (H3bci). Nitrogen-containing ligands are used as auxiliary ligandsin consideration of their ability in reacting with metal ions and main ligands. Properties of these polymers are studied via Infrared Absorption Spectrum, Fluorescence Spectrum, Thermogravimetric (tg) Analysis, Absorption Analysis, Magnetic Property Analysis and Crystal Transformation Analysis, etc.Chapter One introduced up-to-date progress in the research of coordination polymers, aswell as structures of polymers and their promising future in further application. Summarizations on usage and significance in adapting rigid ligands and flexible carboxylic acid in the synthesis of coordination polymers and achievements of our project were also discussed.Chapter Two came with description of the nine novel complexes synthesized through reaction of two flexible carboxylate ligands and cadmium nitrate. These nine complexes are formulated as:{[CdNa(tci)(H2O)]·2H2O}n(1)，{[CdK(tci)(H2O)]·2H2O}n(2)，{[CdNa(bci)(H2O)3]}n(3)，{[CdK(bci)(H2O)3]}n(4)，{[Cd(Hbci)(H2O)]}n(5)，{[(H2en)Cd2(bci)2]·4H2O}n(6)，{[Cd3(tci)2(4-azpy)3]}n(7)，{[Cd(Hbci)(4-azpy)(H2O)2]·6H2O}n(8)，{[Cd3(bci)2(3-abpt)2(H2O)2]·10H2O}n(9)。Novel structures of hybrid metal MOFs were achieved in the synthesisof the first six complexes via adjusting pH value of solutions with different alkalis. Theseventh to ninth complexes were synthesized with H3tci and H3bci and differentnitrogen-containing auxiliary ligands which served to regulate increase sites. Through studieson fluorescence properties and analysis on thermogravimetric properties of all complexesabove, we found that they were all potential for luminescent material application thanks totheir strong fluorescence emission and certain degree of thermal stability.Chapter Three discussed seven novel coordination polymers generated through reactionsof H3tci and H3bci, as based ligands, with nitrogen ligand4,4’-bipyridine (4,4’-bpy) and4-azobipyridine (4-azpy), as ancillary ligands to react with CuⅡand CoⅡ. These nine complexes areformulated as:{[Cu4(OH)2(tci)2(bpy)]·9H2O}n(10)，{[Cu4(OH)2(tci)2(4-azpy)]·4H2O}n(11)， {[Cu(Hbci)(4-azpy)(CH3CN)]·H2O}n(12)，{[CoII16CoIII16(μ4-O)16(tci)16(H2O)12]·40H2O}n(13)，{[Co3(Htci)2(Cl)2]·TEA·9H2O}n(14)，{[Co2(tci)(4-azpy)2(Cl)]·6H2O}n(15)，{[Co(Hbci)(H2O)3}n(16)。 The tenth complex was synthesized by taking advantage of the three carboxyl groupsfrom H3tci ligand and the oxygen of the water bridged connection with CuⅡto to form theclusters of four CuⅡ. After removal of free water, the porosity density of this complex was55.1%being the crystal structure with the largest porosity density synthesized with H3tciligands so far. Moreover, the magnetic structure and absorption property of this complex werealso studied. The eleventh, twelfth and fifteenth complexes were synthesized with H3tci andH3bci as ligands, and4-azpy as auxiliary ligand reacting with CuⅡand CoⅡ. The magneticproperties and crystal structures of the eleventh and twelfth complexes were also studied. Wesuccessfully synthesized a new high-nuclearity mixed-valent Co32cluster with fouroctanuclear [CoΙΙ4CoΙΙΙ4(μ4-O)4]12+subunits, and this cluster was the first complex constructedfrom primary octanuclear unitsthrough Co-O interactions. This was the first Co clustersynthesized with flexible tci3-ligand being reported and it was characterized by magnetismproperty analysis, cyclic voltammetry analysis, electronic absorption spectroscopy, andthermogravimetric analysis. The fourteenth complex was composed of H3tci and CoIIforminga two-dimensional crystal with blue patches, and the sixteenth complex was a pink diamondcrystal.Chapter Four reported four novel coordination polymers synthesized out of two kindsof flexible carboxylic acid H3tci and H3bci with Ba and cadmium nitrate. Their formulas arelisted as below:{[Ba4(tci)2(NO3)2(H2O)7]}n(17)，{[Ba2(tci)(NO3)(H2O)3]·H2O}n(18)，{[Cd6Ba3(bci)6(H2O)15]·3H2O}n(19),{[Cd2Ba(bci)2(H2O)6]·3H2O}n(20)。In this chapter, the processof conformation change from crystal17to18to crystal19to20was studied. Analysis onsolid fluorescence properties of complex17-20implied that the fluorescence properties camefrom the ligands.Chapter Five came with the conclusion of our research including summarizations onstructures and properties of the twenty coordination polymers we synthesized. Highlightingon the strengths and properties of isocyanurate ligands in coordination polymers, promisingfuture of such ligands in generating coordination polymer structures was discussed.