Synthesis And Characterization Of New Indium Microporous Materials

Materials with open-framework structures are of great interest due to their rich structural chemistry and the potential applications in separation, absorption, ion-exchange, and catalysis. In these materials, metal phosphates constitute one of the largest families. However, the study of the open-framework metal phosphates was usually focused on changing the"cation". In recent years, people tried to synthesis new open-framework compounds through changing the"anion"to open a new field for microporous compounds.More recently, [SO4]2- group has been investigated as a possible replacement for the traditional phosphate tetrahedral with great success. It is well known that though [SO4]2- tetrahedron is approximately the same size and shape as [PO4]3-, there is a difference of the charge between them, so it could provide variety and novelty to the structures. After the first members of a family of organically templated open-framework cadmium sulfates were synthesized under hydrothermal conditions by Rao et al, a series of metal sulfates based on transition and rare earth metals had been prepared. However, less exploratory work has been carried out on synthesizing the organically templated main block metal sulfates. Especially, to our best knowledge, there is no report on synthesizing indium-containing sulfates. In this thesis, under mild hydrothermal / solvothermal synthesis conditions, we first successfully prepared three indium sulfates with different organic amine molecules as template agents: (2,2'-bipy)[In2(OH)2(H2O)](SO4)2 (1); (4,4'-bipy)In(OH)(HSO4)2 (2) and (C6H22N4)0.5[In(OH)](SO4)2 (3)。Compound 1 is the first indium sulfate microporous material. Its two-dimensional layer structure is constructed from two distinct motifs, a one-dimensional butlerite-type chain and a single 4-ring (S4R) unit. The two-dimensional layer structure of compound 2 is built up from 1D butlerite-type In(OH)(HSO4)2 chains, bridged by 4,4'-bipy units. Compound 3 is built up by InO4(OH)2 octahedra and SO4 tetrahedra that share their vertices to generate an one-dimensional anionic tancoite-type chain. The TETA cations are in the cavities of the structure delimited by four different chains, and ionic interactions with the anionic chains exist. The one-dimensional chains are extended into three-dimensional supramolecular structure through the hydrogen–bond interactions among the N atoms of TETA cations and O atoms of the anionic chains. In addition, an indium oxalate (4,4'-bipy)2In2Cl4(C2O4) (4) was obtained in the process of optimizing compound 2. It possesses a double chain framework which has never been reported in indium oxalates. Herein, we discussed the syntheses, structural features and some properties of these novel compounds and summarize the rules of synthesis. Our investigation show that it is possible to prepare structural complex open-framework indium sulfates possessing cavity size, limiting apertures, and framework densities rivaling those of the most open zeolites and aluminophosphates under appropriate reaction conditions.Another important change in"anion"is to introduce suitable multidentate ligands (such as oxalate) into inorganic framework as the second ligand. The phosphate groups can be replaced partially or completely by the second ligand, resulting in novel open-framework inorganic-organic hybrid materials. In this way, it is possible to retain some of the robustness of the inorganic framework while including the much greater chemical and topological flexibilities of the organic units. In this thesis, under mild hydrothermal synthesis conditions, we successfully prepared three indium phosphate-oxalates with different organic amine molecules as template agents: (C12N2H8)2[In4(H2O)2(HPO4)2(PO4)2(C2O4)] (6), (C2N2H10)3In6(HPO4)6(PO4)2(C2O4)3·4H2O (7) and (C6N2H14)[In4(H2O)2(HPO4)2(PO4)2(C2O4)2]·7H2O (8). It is noteworth that compound 6 was synthesized by using indium phosphate (C12N2H8)[In(HPO4)(H2PO4)]·H2O (5) as a precursor.The one-dimensional ladder of 5 consists of InO4N2 octahedra, HPO4 and H2PO4 tetrahedra. The structure of 6 is constructed from one-dimensional double six-membered rings columns that connected by the oxalate units into a two-dimensional layer. Comparison of the structures of compounds 5 and 6 clearly suggests that the one-dimensional double six-membered rings column of compound 6 may be viewed as generating from the one-dimensional four-membered ring ladder of compound 5. So, compound 5 probably plays two roles, dissolving in solution acting as In source of reactants and as the precursor for constructing into the structure of compound 6. The crystal structure of compound 7 may be viewed as the stacking of the neutral inorganic layers with the oxalate units as pillars to form the 3D open-framework structure with approximately circular 1D 12-membered channels. Compound 8 displays a three-dimensional open-framewok with 1D 12-membered channels that built up from 1D indium phosphate inorganic chains, cross-linked by oxalate units. In this thesis, we also discussed the syntheses and structural features of these indium phosphate-oxalates and the structural relationships among them.In addition, metal-organic coordination polymers with rigid open frameworks, zeolite-like materials, possess not only porous phases similar to inorganic zeolites but also better performance in the field of optics, electronics, catalysis and magnetism, and have attracted much more attentions. Compared with many novel structures with divalent transition metal centers, the frameworks containing IIIA group metal centers are much less reported. The indium complexes have proven to possess interesting properties in catalytic, so it is very meaningfully to design and synthesis indium coordination polymers.In this thesis, we tried to introduce indium (III) center to the {M/btec/L} (L = N-donor ligand) system, and successfully synthesized two novel indium (III) metal-organic materials, In(2,2'-bipy)(btec)0.5Cl (9) and In2(phen)4(Hbtec)2 (10). Compound 9 exhibits a novel wavelike 2D layer with contorted rhombic grids, while compound 10 possesses a 2D supramolecular framework structure with quadrangle windows.