| The aim of this research is to develop new microporous solids which are complementary to zeolitic phases and which possess frameworks that incorporate REDOX metal centers such as vanadium and manganese.; The synthetic work described in this thesis begins in Chapter 2 with a study of new vanadoborate cluster solids, compounds 1– 7. Three goals were attempted, the first was to use transition metal ions to coordinate the cluster exteriors and serve as cross-linking agents in order to form new porous cluster frameworks.; The second goal was the incorporation of metal ions into the [VB] cluster itself to form new cluster types. Finally, attempts to incorporate larger units such as trangulo-[Mn3O] trimer unit into the vanadoborate clusters were unsuccessful. However they led to the discovery of an organically templated microporous manganese vanadate, or [MnVOx], [enH2][ Mn3(V2O7) 2(H2O)2], 8.; The hydrothermal synthesis conditions for formation of organic [MnVOx] phases was then explored in depth in Chapter 3. Through variation of the reaction conditions, such as temperature, reaction time, pH and the types of aliphatic diamines used, a total of 16 further new compounds 9– 24 were synthesized and characterized by single crystal X-ray diffraction.; In Chapter 4 exploration of the [NiVOx] and [CoVOx] systems using the aliphatic diamines as organic structure-directing agents reveals quite different chemistry from Chapter 3. A total of 12 new compounds 25– 36 were synthesized including several novel salts and hybrid solids. The difference in the solids produced lies in the preference of Co and Ni for diamine chelation.; Finally in Chapter 5 the transition metal vanadates phases formed using planar aromatic amines such as imidazole and pyridine are studied. A further 10 new compounds 37–46 were made and characterized. Among them, a novel 3-D microporous phase [ImH][Mn 3(OH)2(V4O 13)], 37 is found. This contains mixed valence MnII and MnIII centers, is found to be thermally stable up to 350°C and capable of ion-exchange. The compound is thus a potential candidate for both acid and REDOX catalysis.; In this thesis, apart from appreciating the structural diversities of the compounds, their thermal stability, magnetic, and ion-exchange properties are evaluated. Low temperature ferro-magnets as well as anti-ferromagnets are observed for the [MnVOx] solids. (Abstract shortened by UMI.)... |
