Synthesis, Structure And Property Characterization Of Actinides Organic Frameworks

Metal-organic frameworks(MOFs) are built up from metal ion nodes(or clus-ters) and multitopic organic linkers by self-assembly through the coordination bonds. MOFs have attracted increasing interest as a new type of porous materials in application of gas storage, magnetic, luminescence and catalysis.Over the few years actinide elements also become a hot research topic, especially the uranium and thorium, due to its higher coordination numbers and potential applications in nuclear waste storage. And many actinide elements also exhibit its unique structures and significance in the area of topology and mineralogy.In this work, we synthesized several U-MOFs and Th-MOFs using the solvothermal and ionothermal. The related properties are further studied, and the concrete working are listed as follows:(1) 1,3,5-tri(4′-carboxylphenyl) benzoic acid(H3L1), 3,5-di(4′-carboxylphenyl) benzoic acid(H3L2) and Tris-(4-carboxylphenyl) phosphineoxide(H3L3) were respectively reacted with uranyl nitrate under solvothermal conditions, giving three complexes which were characterized by Single crystal X-ray diffraction, PXRD, TGA, Circular dichroism spectrum, Second Harmonic Generation and Luminescence properties. Single crystal X-ray diffraction reveals that compound 1 displays a layered structure and compound 2, 3 display 3D framework. Moreover, the 3D compound 2 exhibits significant umbellate distortions in the uranyl equatorial planes studied thoroughly by linear transit calculations and high β and γ radiation-resistance and chemical stability in p H range from 3 to 12. This compound 2 is able to selectively remove cesium from aqueous solutions while retaining the polycatenated framework structure. The compound 3 also exhibits large amounts of Th(IV) from aqueous solutions owing to the coordination capabilities of P=O moieties.(2) Tris-(4-carboxylphenyl) phosphineoxide(H3L3) was reacted with thorium nitrate though solvothermal and ionothermal respectively, giving two different compounds. Single crystal X-ray diffraction reveals that the compound 5 synthesized by ionothermal exhibits larger pore and chiral structure. In addition, Those compounds also ware characterized by PXRD, TGA and their luminescence properties.(3) Using 1,3,5-tri(4′-carboxylphenyl) benzoic acid and thorium nitrate, the graphene-like(6,3) sheet topologies compound 6 and 7 were synthesized. Because of the similar structure with compound 1, we carried out the doping experiment successfully. Interestingly, Changing the rigidity of the ligand by replacing H3L1 with 4,4’,4’-nitrilotribenzoic acid(H3L4), we get a 3D graphene-like(6,3) structures. Those compounds also ware characterized by PXRD, TGA and Luminescence properties.