AbstractsChemistry

This dissertation describes the synthesis of a series of transition metal compounds and their reactivity with hydrogen and carbon dioxide for application in reversible hydrogen storage in organic molecules. Chapter 1 is a review of hydrogen storage molecules and discusses each from the perspectives of safety, availability, and environmental impact. Heterogeneous and homogeneous catalysts for dehydrogenation of these molecules are also discussed here. In Chapter 2, a family of PNP pincer-supported iron compounds is investigated by Mössbauer spectroscopy and magnetic circular dichroism with the goal of elucidating the degree of solution-state flexibility of the PNP pincer ligand. Chapter 3 expands on this family of PNP pincer-supported iron compounds with the synthesis of several new compounds through reaction with hydrogen and carbon dioxide. Furthermore, these compounds are shown to be highly active catalysts for formic acid dehydrogenation in the presence of a Lewis acid co-catalyst. The action of the Lewis acid co-catalyst is further demonstrated in Chapter 4, where PNP pincer-supported iron compounds are used as catalysts for aqueous-phase methanol dehydrogenation. Chapter 5 describes the synthesis, characterization and reactivity of a family of palladium and nickel compounds supported by allyl, cyclopentadienyl, and indenyl ligands. These compounds are shown to react with simple electrophiles, although they do not show the desired reactivity with carbon dioxide.