The compound class of extended polycyclic aromatic hydrocarbons is frequently used in materials chemistry due to their strong absorption and emission in the visible region of light. These properties can further be tailored by introducing electron withdrawing and electron donating groups to the parent scaffold. In the group of H. A. Wegner, a modular bidendate Lewis acid catalyzed inverse electron-demand Diels-Alder (IEDDA) reaction was developed to construct push-pull substituted benzo[b]fluorenes giving access to a variety of substitution patterns. By density functional theory (DFT) studies, structures with optimal substitution pattern were identified and subsequently synthesized. Among these compounds, one candidate showed a strong solvent dependence for the fluorescence, giving rise to the different emission colors shown in the picture.