Syntheses, Structures And Properties Of Novel Metal-organic Frameworks Based On Multitopic Carboxylic Acid

In the past twenty decades, metal-organic frameworks (MOFs) attact people’sinterest. They are new class of compounds between inorganic and material chemistrywith potential applications. MOFs have been paid extensive attention, not only becausethe building blocks of metal ions and organic ligands are designable, but also becausethey exhibit very charming molecular topological networks and potential applications invarious fields such as gas adsorption, photoluminescence property, magnetism, catalysisand nonlinear optical properties and so on.According to the crystal engineering method, several MOFs with new topologicalstructures have been synthesized hydrothermally in this thesis. Based on their structures,their potential properties have been discussed. In this thesis, using rigid/flexiblemultitopic carboxylic acid ligands, ten metal(Ⅱ) complexes have been synthesized andstructurally characterized by single-crystal X-ray diffraction. Their photoluminescenceand photocatalytic properties have been discussed. The main contents in the thesis weresummarized as follows:In the first chapter, it has been introduced the basic concept, research backgroundand progress in coordination chemistry. The synthesis methods and influencing factorsfor metal-organic frameworks and their applications have also been demonstrated.In the second chapter, a novel hemirigid multitopic ligand,benzene-1,2,3-triyldioxy-triacetic acid (H3L1) was synthesized. Based on H3L1, threemetal(II) complexes formulated as Cd3L12(H2O)3·H2O(1), Zn(L1)(BPPA)1/2·(HBPPA)(BPPA=N,N′-bis-(4-pyridyl)phthalamide)(2), M(HL1)(phen)(H2O)2·H2O(phen=phenanthroline)(M=Zn (3) and Co (4)) and Cd(HL1)(2,2’-bpy)(H2O)·5H2O(2,2’-bpy=2,2’-bipyridine)(5) have been hydrothermally synthesized and structurallycharacterized by single-crystal X-ray diffraction. Complex1features a3D topology.Complex2exhibits a2D framework. Complexes3and4are isostructural, and they aremononuclear Zn(II) and Co(II) complexes, respectively, in which strong intramolecularπ-π stacking interactions are observed. Complex5is a mononuclear Cd(II) complex,which is assembled into3D supramolecular architecture via strong intermolecular π πstacking interactions and H bonds. L13-or HL12-displays different coordination modesin the five complexes. Complexes1-3and5show different UV absorptions, emissionspectra, and photoluminescence lifetimes. In the third chapter, a hemi-rigid multitopic ligand,1,3,5-triazine-2,4,6-triyltrithio-tri-acetic acid (H3L2) was synthesized. Based on H3L2,five metal(II)-complexes formulated as Mn3(L2)2(2,2′-bpy)2(H2O)2·2H2O(6),Zn3(L2)2(2,2′-bpy)2·2H2O(7), Pb2L(ox)1/2(H2O)(H2ox=oxalic acid)(8), Pb3L2(H2O)2(9) and Ni6L4(PEP)6(H2O)127H2O (PEP=4-(2-(pyridin-4-yl)ethyl)pyridine)(10) havebeen hydrothermally synthesized and structurally characterized by single-crystal X-raydiffraction. Complexes6and7exhibit similar (6,3)-connected2D layers with kgdtopology. Complex8features a novel4-nodal (3,4,5,6)-connected3D framework withan unusual (42.63.8)(42.68)2(42.6)2(43.611.8)2topology and complex9presents a3-nodal(5,6,8)-connected3D framework with a novel (3.44.53.62)(33.412.55.68)(35.47.53)topology. Complexes8and9are hybrid Pb(II) oxides, in which2D Pb-O-Pb layer isobserved. Complex10shows a3-nodal (3,4)-connected3D framework with a novel(6.72)2(64.7.8)2(74.8.10) topology. L23-displays different coordination modes in thecomplexes. Complex6is a Mn(II) complex and it shows a negative MFE on thefluorescence. Complex7is a Zn(II) complex with a positive MFE on the fluorescenceproperty. Complexes8and9show different UV absorptions, emission spectra,photoluminescence lifetimes and they are photocatalytic active for the decomposition ofmethyl orange under UV light irradiation.