| As the representative of the actinide complexes,uranyl complexes have attracted more attention not only because of their rich topologies and diverse packing modes,but also their powerful potential application value in photocatalysis,nonlinear optical materials,adsorption materials,mineralogy etc.Especially,the potential application in nuclear power and nuclear fuel cycle of uranyl complexes of radiation chemistry has become a hot research area.It is more important to study the mechanism between uranium and organic or inorganic ligands,which will provide some effective theoretical basis for nuclear waste disposal techniques and nuclide migration patterns in nature.The ultimate goal is to achieve recycling of nuclear fuel.The dissertation mainly focuses on the element of uranium.Under hydrothermal conditions,four nitrogen-containing flexible polycarboxylic ligands have been selected to construct uranyl coordination polymers.The impacts on the system of the second metals and the second ligands have been also studied.The main contributions in this work are below:1.Two uranyl complexes have been constructed by a tripodal flexible zwitterion ligand 1,1 ’,1"-(2,4,6-trimethylbenzene-1,3,5-triyl)-tris(methylene)-tris(pyridine-4-carboxylic acid)trichlorine(H3LCl3).Reaction of H3LCl3 and uranyl acetate dihydrate,uranyl nitrate hexahydrate affords[(UO2)2L(μ3-O)Cl2]·2H2O(1),[UI2L2]·2NO3 H2O(2)respectively.Complex 1 contains tetranuclear motifs,resulting in a two dimensional(2D)layer structure.Complex 2 shows a three-dimensional(3D)frame structure.The results indicate that anionic-controlled can generate from 2D to 3D transformation of uranyl complexes.Also,the infrared spectrum,thermal analysis,pH stability and fluorescence property for each complex have been analyzed.2.Under hydrothermal conditions,two uranyl complexes[(UO2)2(H2O)2(Hbci)2](3),[(UO2)2(H2O)2(μ3-O)(Hbci)]·2H2O(4)have been constructed by the reaction of the ligand bis(2-hydroxyethyl)isocyanurate(H3bci)and uranyl acetate dihydrate,uranyl nitrate respectively.Four hetero-nuclear metallic complexes[Mn0.5(H2O)2(UO2)0.5(Hbci)](5),[Co0.5(H2O)2(UO2)0.5(Hbci)]·4H2O(6),[Ni0.5(H2O)2(UO2)0.5(Hbci)]·6H2O(7),[Zn0.5(H2O)2(UO2)0.5(Hbci)]·4H2O(8)have been obtained by the addition of 3d transition metals.Complex 3 shows one-dimensional(1D)chain structure,complex 4 reveals a 2D layer with the second building units of tetranuclear clusters.Complexes 5-8 display similar accumulational modes,with 2D grid spatial structures.The structures have been characterized by X-ray single crystal diffraction,and the properties of elemental analysis,infrared spectroscopy,thermogravimetric analysis,pH stability and fluorescence have been also studied.The ligand of complexes 5-8 exhibit three different coordination modes.3.Reaction of tris(2-hydroxyethyl)isocyanurate(H3tci)with uranyl acetate dihydrate,by the addition of 3d transition metals and some nitrogen-containing templates respectively,yielded seven novel uranyl complexes[(UO2)2(tci)2]i/2-·[Mn2(μ2-O)(H2O)8]1/2+·2H2O(9),[(UO2)2(tci)2]1/2-·[Co2(μ2-O)(H2O)8]1/2+(10),[(UO2)2(tci)2]1/2-·[Zn2(μ2-O)(H2O)8]1/2+·2H2O(11),[UO2(tci)]-3·[Ni(H2O)6]2+(H3O)+·2H2O(12),[UO2(tci)]-·[NH(CH2CH3)3]1/3+·(2H30)1/3+(13),[UO2(tci)]-·(C10H9N2)+·H2O(14),[UO2(tci)]-·(C5H6N)+·2H2O(15).Additional metals and the second ligands are free in the complexes,acting as the templates and compensation of the charge balance.Complexes 9-11 are isomorphic,showing the layered structure of graphene.The packing of 12 and 13 are similar,revealing four overlapped 2D structures with the infinite circinate units.The configurations of H3tci have been analyzed,which shows a chair-shaped in complex 15 compare with the bowl-shaped of the remaining complexes.The results of fluorescence indicate that the seven complexes own fluorescence emissions.4.A flexible hexapodal ligand of 1,3,5-triazine-2,4,6-triamine hexaacetic acid(H6TTHA)have been designed and synthesized.Under hydrothermal conditions,with pH-controlled,two uranyl complexes[(UO2)5(H20)3(H3O)(TTHA)(HTTHA)]·8H2O(16)and[(UO2)4(H3O)2Na(TTHA)(HTTHA)]·H2O(17)have been obtained by the reaction of H6TTHA and uranyl acetate dihydrate,uranyl zinc acetate hexahydrate respectively.Complexes 16 and 17 reveal the complicated 3D structures which contain three novel coordination configurations.Complex 17 provides the theoretical basis for the activation of the uranyl oxygen atoms with the interaction of U=O-Na. |
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