Non-covalent bonding between aromatic rings, such as edge-to-face (CH–π) and parallel-displaced (π–π stacking) interactions, are critical to biological and chemical process, inspiring many supramolecular scientists to utilize them in host-guest interactions. However, although aromatic hydrocarbons in the environment are common, the majority of supermolecules rely on heteroatoms for stability. We investigated a series of all-hydrocarbon π-conjugated complexes consisting of [n]cycloparaphenylene (nCPP) hosts and polycyclic aromatic hydrocarbon (PAH) guests. We built a framework that theoretically selects stable PAH@nCPP complexes and experimentally confirmed more than 10 of the predicted assemblies, which are stabilized exclusively by CH–π interactions. Our DFT calculations further suggest that the strength of collective CH–π interactions become stronger than π–π interactions in these curved π-systems. We anticipate that the PAH@nCPP framework will provide a versatile way to integrate the advantageous properties of organic semiconductors (conductivity and optoelectronic) with those of host-guest complexes (stimulus-responsive and stress-dissipative behavior).

Semiconducting host-guest complexes based on cycloparaphenylenes and polycyclic aromatic hydrocarbons stabilized by CH-π interactions.

ACS Spring Meeting 2021

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