Structural Modifications of Dithienophospholes for Applications as Functional Materials

Recent breakthroughs in synthetic chemistry have revolutionized main-group molecules, elevating them from mere laboratory curiosities to powerful materials with broad applications. A primary focus has been on electron-accepting or -deficient materials, driven by their historical limitations in availability and stability, which have hindered practical applications. The incorporation of heavier main-group elements, including Si, Ge, P, As, Sb, Bi, S, Se, and Te, has proven advantageous for electron-accepting materials due to their polarizable molecular orbitals (MOs) readily accessible to electrons and nucleophiles. This foundation has spurred research in materials chemistry across various applications, encompassing optoelectronic devices (OLEDs, OPVs), energy storage (batteries, capacitors), fluorescent sensors (biological, physiological), catalysis, and synthesis. Among main-group-element-based materials, organophosphorus compounds hold a privileged status, with their frontier orbitals easily modifiable through chemical, structural, or electronic means at the phosphorus center itself, without necessitating kinetic stabilization. The five-membered phosphorus-based heterocycle, phosphole, is particularly captivating in this context. Extensive studies have unveiled the intricate σ*-π* interaction within phospholes, endowing them with intriguing electron-accepting properties, while preserving morphological and physiological stability for practical utilization. Furthermore, phosphorus introduces easily accessible, low-lying antibonding orbitals, leading to Lewis acidic phosphorus species, a departure from the conventional perception of phosphorus as an electron-rich element. These species exhibit unconventional chemical reactivity through hypervalency. This thesis advances conjugated materials by employing the unique structures and electronics of organophosphorus compounds. It discusses how these materials can be harnessed to design functional materials with exceptional electronic, chemical, and structural properties, contributing to the realm of functional materials.