The design and synthesis of polycyclic conjugated hydrocarbons via the incorporation of bifunctional Diels-Alder building blocks

Abstract

In Chapter 1, we discuss the synthetic progress, challenges, and applications of polycyclic conjugated hydrocarbons (PCHs). In particular, we explore synthetic strategies to access polycyclic aromatic hydrocarbons and nonbenzenoid oligoacenes, and also discuss synthetic efforts to stabilize, solubilize and tune the properties of these classes of molecules. In Chapter 2, we describe the synthesis and characterization of seven new linearly conjugated ladder compounds of the phenylene-containing oligoacene (POA) molecule class. Each derivative incorporates a fused four-membered-ring linkage in the acene-like backbone. Crystal packing, spectroscopic and electrochemical properties of the molecules are described. In Chapter 3, we describe the synthesis of a set of naphthazarin-containing polycyclic conjugated hydrocarbons, which were accessed through sequential Diels-Alder reactions on a tautomerized naphthazarin core. Iptycene and POA motifs were incorporated into the synthesis of these compounds. We discuss their complexation with BF₂ to achieve full conjugation across the molecular backbone, and the potential these compounds demonstrate for naphthazarin's utility in the synthesis of novel organic electronic materials. In Chapter 4, we describe the synthetic progress towards a thirteen-aromatic-ring extended POA. Two different synthetic approaches were employed, and we discuss the pros and cons of each approach to achieve the final target. In Chapter 5, we discuss a convergent synthesis of a heptiptycene PCH, its crystal stacking properties, photophysical characterizations, and its effectiveness as a selector molecule in chemiresistive sensing with single-walled carbon nanotubes (SWCNTs).