Synthesis, Structure, and Chemical Properties of Bora-sumanene Compounds

The aim of the proposed research will be to synthesize borasumanenes and investigate their chemical properties. Bowl-shaped aromatic compounds are the central building blocks of fullerenes, carbon nanotubes, and other synthetic bowl-shaped polycyclic aromatic hydrocarbons. These compounds exhibit unique physical and chemical properties, including bowl-to-bowl inversion, chiroptical properties, host–guest recognition, and electronic conductivity. Sumanenes are among the most well-studied bowl-shaped molecules. In recent decades, heterasumanenes, particularly those including group 14, 15, and 16 elements, have been designed and successfully synthesized. Boron, a group 13 element, has empty 2p orbitals, unique electronic properties, and a small atomic radius, and therefore would be expected to endow borasumanenes with both a bowl structure and anti-aromatic properties. Despite these attractive properties, borasumanenes have not yet been reported. Recently, we successfully synthesized the first example of stannole-sumanene compound, which might be used as a key precursor for the synthesis of related borasumanene species. Based on these results, we plan to synthesize a new class of borasumanenes, heterasumanenes, and their derivatives. We anticipate that the boron-containing five-membered rings found in such borasumanenes will be highly reactive and can be used for further functionalization. The physical and chemical properties of the borasumanene molecules will be further investigated using density functional theory computations and spectroscopy. The findings of this project will improve our fundamental understanding of borasumanenes and their potential future application in optoelectronic devices.