Syntheses, Properties Of Organometallic Frameworks Built From Half-Sandwich Iridium/Rhodium Based On Carboxylate Ligands

In this dissertation, we have described half-sandwich Cp*Ir (Cp*=η5-C5Me5) fragments react with carboxylic acids including aromatic carboxylic acids, unsaturated alkyl acids and saturated alkyl acids under mild conditions. As a result, organometallic macrocycles and complexes have been obtained via C-H activation, B-H activation or Metal-Metal bond through the kind of reactions. Especially, when tricarboxylic acid was treated with Cp*Ir/Cp*Rh complexes as the same way as above, poly-nuclear organometallic cages were obtained. Interestingly, when the guest who was located in the host cage was changed, the host frameworks were transformed from icosanuclear compounds to hexanuclear compounds.1. Firstly, the aromatic dicarboxylic acids were tested to react with [Cp*2hIr2(pyrazine)Cl2] which were first treated with access AgOTf at room temperature, a series of red powder compounds were obtained in moderate yields. The red compounds were fully characterized by IR, NMR and EA. The molecular structures of the compounds were primarily confirmed that they show high symmetry geometry. In order to further testify their structures, single crystal X-ray diffraction was carried out on determining the unambiguous structures. Indeed, their structures were macrocyclic frameworks containing C-M (M=Ir and Rh), which were built via C-H activation. Although the N-donor ligands were changed (from pyrazine to4,4’-biprydine (bpy) or trans-1,2-Bis(4-pyridyl)ethylene (bpe)), the main frameworks were supported by C-M bondings.2. When unsaturated alkyl acid like fumaric acid was treated with Cp*Ir fragments as the same procedure in the similar conditions as above, red powder compounds were also obtained after purified. Organometallic macrocyclic framework of the complex structure was confirmed by single crystal X-ray diffraction. Similarly, C-H activation of Fumaric acids utilized as building block has taken place. When [Cp*2Ir2(bpe)Cl2] was taken part in the reaction, the [2+2] photoaddition reaction has been observed from the molecular structure of the product.3. Carborane di-carboxylic acids, which are pseudo-aromatic ligands, reacted with Cp*Ir fragments under mild conditions, giving red powder compounds, too. The products were structurally characterized by IR, NMR and EA, high symmetry geometry was firstly classified. Furthermore, X-ray analysis have ultimately confirmed their molecular structures, which are tetranuclear macrocyclic frameworks involving B-H activation. In order to testify C-H activation and B-H activation which is easier, o-carborane monocarboxylic acid was treated with Cp*Ir fragments. As a result, binuclear complex was built via C-H activation, suggesting that C-H activation is easier than B-H activation.4. When saturated alkyl acid like acetic acid and malonic acid react with [Cp*IrC1(μ-Cl)]2treated with silver salts, yellow powder compounds were obtained after purified via recrystallization. The formation of Ir-Ir bonds in the compounds were observed by X-ray analysis, which differed from above organometallic frameworks involving C-H activation.5. Ternary carboxylic acid like1,3,5-benzonic acid took part in the reaction of Cp*Ir or Cp*Rh fragments in the same conditions as above, yellow block crystals were obtained via diffusion of ether into their methanol solution. Icosanuclear nanocage framework of these complexes was unambiguously observed by X-ray analysis. Interestingly, as the guest molecules which were located in the nanocage changed, the frameworks of the host cages were transformed from icosanuclear cage to hexanuclear cage.