Different Molecular Arrangement of Perylene in Metallic and Semiconducting Carbon Nanotubes: Impact of van der Waals Interaction

The arrangement of molecules on material surfaces has been a central focus in the fields of chemistry and physics. The molecular arrangement on two-dimensional surfaces has been extensively studied, and the electronic properties of substrates are one of the crucial factors for the arrangement. Recently, the arrangement of molecules in tubular materials can be investigated by using carbon nanotubes. In this study, the preferential molecular arrangement of perylene in single-walled carbon nanotubes (SWNTs), which is determined by their electronic properties, is reported. A combination of transmission electron microscopy observations, optical measurements, and first-principles calculations revealed differences in the molecular arrangement of perylene in metallic and semiconducting SWNTs. Perylene molecules in metallic SWNTs formed H-type molecular dimers, while those in semiconducting SWNTs were one-dimensionally stacked with their stacking axis directed along the nanotube axis. The difference in the molecul...