| The paradigm of metal-ligand cooperation pervades the fields of organometallic chemistry and catalysis. In its simplest form, metal-ligand cooperation can be viewed as a strategic partnership between the metal and its surrounding ligand system to achieve new modes of chemical reactivity. Classic cases of metal-ligand cooperation involve elaborate chiral catalysts containing noble metals for enantioselective hydrogenation reactions, which are able to generate chiral compounds of great value to the pharmaceutical, agrochemical, and flavour industries. In recent years, creative design innovations have allowed chemists to create new molecules that use inexpensive iron-based catalysts for the same enantioselective transformations. Furthermore, metal-ligand cooperation has been recently employed in catalyst design pertaining to renewable/green energy applications. In particular, the activation of benign small molecules such as water, carbon dioxide, and methanol can be performed with well-defined molecular catalysts exhibiting metal-ligand cooperativity. This thesis encompasses two areas in which metal-ligand cooperation plays a vital role in the overall reactivity. First, new ruthenium complexes containing bidentate, tridentate, and tetradentate ligand systems are synthesized and investigated for applications in water splitting (2H2O→2H2 + O2). Second, computational investigations are performed to elucidate the mechanism of ketone hydrogenation using three generations of iron hydrogenation catalysts containing tetradentate PNNP ligand frameworks. |
