For a given number of skeletal atoms, the π-electron count of an unsaturated heterocycle can be modified by the incorporation of heteroatoms from different periodic groups. Sulfur and nitrogen are particularly effective in this regard, as their high electronegativity can stabilize electron-rich π-systems. A variety of aromatic, anti-aromatic, and radical systems can be prepared from admixtures of these elements. While the properties of these ring systems are interesting in their own right, the compounds are not without relevance in the design of new materials. The strong interannular interactions that are developed between these rings in the solid state makes them ideal candidates for the fabrication of molecular conductors. The origins and development of this area of research are the subjects of this presentation.