| The growing global demand for energy has put a strain on the environment through the release of greenhouse gases. An important challenge facing society and science is the development of alternative, clean sources ' of energy and the means by which to store, transport and utilize these energy sources. One prospect in this endeavor is the development of a hydrogen based energy economy. In this work, the development of catalytic processes for the reversible storage of hydrogen is described. These iridium catalysts are capable of driving the hydrogenation of N-heterocylic organic molecules at room temperature under 1 atm of hydrogen and the dehydrogenation of the saturated substrates at 110-140°C. In addition, the catalytic dehydrogenation of common, cheap polyols was explored using a family of novel complexes. These reactions produced hydrogen gas as well as lactic acid with good selectivity.;Another challenge facing chemists is the development of more energy efficient, environmentally friendly and cheap processes for the synthesis of important chemicals. Another challenge facing chemists is the development of more energy efficient, environmentally friendly and cheap processes for the synthesis of important chemicals. As an extension of the N-heterocycle hydrogenation project, these same iridium catalysts were found to be competent aldehyde hydrogenation catalyst. In the presence of both N-heterocycles and aldehydes, this system catalyzed the tandem reduction/N-alkylation of these substrates in a one-pot reaction. Iridium catalysts, while effective, are quite expensive making the development of cheaper catalysts an attractive pursuit. This thesis also describes the development of a very cheap and efficient means of hydrosilylating a range of organic substrates using simple borohydride catalysts and abundant silane materials. |
