Salen-based Metal Complexes in Solid State Materials as a Platform for the Capture and Conversion of Carbon Dioxide

Abstract

Since the industrial revolution, the consumption of fossil fuels has been rapidly increasing to cater for the needs of an ever growing world population. The annual 30 billion tonnes of carbon dioxide released into the atmosphere cannot be absorbed by the natural carbon cycle alone unless it is supported by an anthropogenic one. The potential hazards of sequestering carbon dioxide has seen the exploration of multifunctional solid state materials as candidates to capture carbon dioxide and convert it into commercially viable chemicals; however, the high energy penalty associated with the reduction of carbon dioxide requires a catalyst to lower the activation energy. The redox active salen metal complex has found applications in both chemical and electrochemical catalysis. This thesis reports the design and synthesis of discrete salen metal complexes and their incorporation into Metal Organic Frameworks (MOFs) and Porous Organic Polymers (POPs) for the capture of carbon dioxide and its electrochemical conversion. The investigations reported in this thesis uncover a number of important insights into the mechanisms of redox activity in salen metal complexes en route to their immobilisation into solid state materials. Not only does this study pave the way towards the further design of redox active salen based multifunctional materials, but it also aids in a means to understand the factors that govern their rich chemistry.