Synthesis and Properties of Cross-Shaped Polycyclic Aromatic Hydrocarbons

The synthesis and characterization of cross-shaped π-extended dibenzo[e,l]pyrene derivatives with combined fjord and armchair edge structures were reported. The target molecules were synthesized via Yamamoto coupling and Scholl reactions, and their structures were fully characterized by nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), and single-crystal X-ray diffraction. Photophysical studies revealed a significant redshift in absorption and emission spectra compared to the parent dibenzo[e,l]pyrene, attributed to the extended π-conjugation system. Density functional theory (DFT) calculations provided insights into the molecular orbital distribution and reduced bandgap resulting from the elongated conjugation pathway. This work offers a versatile synthetic strategy for polycyclic aromatic hydrocarbons with tailored edge topologies and paves the way for their potential applications in optoelectronic materials.