| Metal-Organic Frameworks(MOFs) have been attracting significant attention and becoming a research hotspot due to their potential applications in many areas, such as gas storage and separations, heterogeneous catalysis, magnetism, optical material, recongnition of cations, anions and samll volume of molecules. In order to make sense of the CPs, we synthesized three kinds of multicarboxyl ligands which having aromaticity with abundant π electrons and lone-pair electrons in nitrogen atoms. We got a series of new CPs processing elegant structures and potential properties by using the three ligands with a sequence of transition metal salts and rare-earth metal salts under solvothermal conditions. The main works of this thesis are listed below.1. We chose a multidentate(N and O atoms) rigid ligand---1-(4-carboxyphenyl)-1,2,4-triazole(Hcpt), combined with serveral kinds of transition metal salts and rare-earth metal salts to construct CPs under hydrothermal conditions. Eleven novel CPs, [Cd(cpt)2(H2O)4]n(1), [Mn(cpt)2(H2O)4]n(2), [Zn(cpt)2(H2O)4]n(3), [Co(cpt)2(H2O)4]n(4), [Ni(cpt)2(H2O)4]n(5), [Cu(cpt)Br]n(6), {[Pr(cpt)3(H2O)3]?H2O}n(7), {[Nd(cpt)3(H2O)3]?H2O}n(8), {[Cd(cpt)2]?2H2O}n(9), {[Cu(cpt)2]?2H2O}n(10), [Cd(cpt)(HCOO)]n(11), were synthesized.Compound 1-5 have similar coordition modes and configurations, intermolecular hydrogen bonds play important roles during the constructions. Compound 6 reveals an interesting Cu-Br bridge. The weak intermolecular hydrogen bonds interactions of play positive roles in the construction of the supermolecular structures of compound 7 and 8. Compound 9 and 10 have 3D porous frameworks containing 1D channels. Compound 9 reveals a(3,6)-connected network with point symbol {42.6}2{44.62.87.102}, the topological type is flu-3,6-C2/c, to the best of our knowledge, this type was rarely observed in MOFs. In compound 10, the centre Cu atoms can be regard as a 4-connected node, the topological type is dia-diamond with point symbol {66}. Compound 11 revels novel pillared-layer structure with 6-connected msw topology.2. We designed and synthesized a new flexible antler-like multidentate ditopic ligand--- H4 L. For that the flexible “-CH2-” groups allow H4 L to adjusted itself to the geometric requirements, which may produce novel structures. Five new CPs, {[Zn L]?2(CH3NH2CH3)}n(12), {[Mn L]?2(CH3NH2CH3)}n(13),{[Mn3L1.5(H2O)4]?3(H2O)}n(14),{[Mn2L(H2O)4]}n(15),{[Cd2L(H2O)2]·DMF·H2O}n(16) were constructed under hydrothermal conditions with ligand and serveral kinds of transition metal salts. Compound 12 and 13 revel 2D-layer frameworks and 3D supermolecular structures with the assistant of in situ generated [(CH3)2NH2]+ molecules. Compound 14 shows 2D-layer frameworks and 3D supermolecular structures with the help of the weak intermolecular hydrogen bonds. Compound 15 reveals a 3D framework with Mn-clusters. Compound 16 have a 3D porous framework containing 1D channels. As our expected, the flexible ligand adjusted itself and revealed different configurations in compound 12-16. In addition, compound 16 shows differernt fluorescence responses to different organic solvents, especially for nitrobenzene, this phenomena indicates compound 16 can act as a fluorescence sensor for detecting trace amount of nitrobenzene.3. We selected a multidentate carboxyl ligand--- H3 btpca with heavy molecular weight. Combined the ligand with Cd(II) ions and a second lingand under hydrothermal conditions., we successfully got a new CP, [Cd(btpca)(C12H12N2)]n(17), Compound 17 reveals 1D infinite chain-structures and shows good fluorescence properties.In summary, seventeen CPs were synthesized under hydrothermal environment by using two kinds of lingand(rigid and flexible). The CPs were characteristics by many methods, such as X-Ray powder diffraction(PXRD), thermogravimetric analysis(TGA), FT-IR, elemental analysis and luminescent. Our work enriched the design and synthesis of CPs. The results show that these CPs process unique structures and good fluorescence properties. |
PDF Full Text Request