New Conjugated Materials for Clean Energy Applications

Abstract

This thesis details the synthesis, characterization, and applications of asphaltene model compounds for use in green energy technologies. Chapter 1 introduces green energy technologies and the current state-of-the-art organic semiconductors currently utilized in the field, as well as the concept of the asphaltene class of molecules and how they can be utilized to inspire the design of novel organic semiconductors. Chapter 2 discusses the synthetic attempts to develop a hole-transporting material on the asphaltene-derived 5,7-dihydroindolo[2,3-b]carbazole platform. While the synthesis of the building block, albeit atom-inefficient, was successful, the work presented in this chapter remains incomplete due to reactivity challenges in cross coupling reactions as well as challenging purification and characterization of the more successfully synthesized target molecules. Moving forward, Chapter 3 delves into the use of aromatic fluorination as a strategy to enhance the processability of electron-transporting materials for use in printed organic photovoltaic devices with the F-PDIN-EH compound. The F-PDIN-EH material was characterized by UV-Visible spectroscopy and cyclic voltammetry, which confirm the maintenance of the desirable electronic structure of non-fluorinated PDIN-EH for photovoltaic applications, as well as solubility measurements to probe the hypothesized change in processability, indicating upwards of nearly 10-fold enhancements to solubility. Finally, in Chapter 4, the focus shifts towards the use of asphaltene-inspired conjugated aromatics for use as lithium-ion capture agents. Simple aryl anhydrides were functionalized through condensation reactions with amino-benzo-9-crown-3 to efficiently generate aryl imides showing selective lithium-ion capture and release. Importantly, this chapter demonstrates that the conjugated backbone can be further functionalized without having an impact on the ability of the crown ether moiety to selectively capture lithium from aqueous solutions such as brine waters.