Recent Advances of Polycyclic Aromatic Compounds Containing Four-Membered Rings

Polycyclic aromatic compounds containing four-membered rings usually exhibit unique photophysical and chemical properties, and have potential application value in many fields. The synthesis methods, intermolecular stacking behaviors, photoelectric properties and carrier mobilities of linear, angular, helical, and ring-shaped polycyclic aromatic compounds containing four-membered rings are reviewed. The research shows that the surface synthesis method is more conducive to the preparation of regular-shaped polycyclic aromatic compounds, linear molecules show higher carrier mobilities, angular molecules usually show higher anti-aromaticity, and helical molecules have optical rotation properties and a larger optical band gap. It should be emphasized that the numbers of four-membered rings and its position in molecules have a decisive influence on their photoelectric properties.