Kritchasorn Kantarod, Khetpakorn Chakarawet, Amporn Saekee, Darunee Soorukram, Chutima Kuhakarn, Panida Surawatanawong, Vichai Reutrakul, and Pawaret Leowanawat*

Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand

Supramolecular “host–guest” chemistry can organize molecules into predictable patterns, which is important for designing functional materials. In this study, we created a new curved carbon-rich molecule (a saddle-shaped nanographene 1) designed to match the shape of spherical carbon molecules called fullerenes (C₆₀ and C₇₀). We synthesized this host using a palladium-catalyzed ring-forming reaction and then tested how strongly it binds fullerenes in solution and how the molecules pack together in crystals. We found that the host binds both C₆₀ and C₇₀ with moderate strength (stronger for C₇₀), and crystal structures revealed that the complexes form distinct, ordered zigzag arrangements—C₆₀ produces perpendicular zigzag arrays with short fullerene–fullerene contacts, while C₇₀ forms a single-direction zigzag pattern. These results show that the “negative curvature” of the host and the positions of its substituents can control how fullerenes assemble, providing practical design rules for building fullerene–nanographene materials with tunable molecular organization.

Acknowledgement: This project is funded by the National Research Council of Thailand (NRCT) and Mahidol University (N42A650367), Faculty of Science, Mahidol University (Fundamental Fund: fiscal year 2023 by the National Science Research and Innovation Fund (NSRF)). The authors thank the Center of Excellence for Innovation in Chemistry (PERCH-CIC) for scientific instrumental support and Dr. Thanthapatra Bunchuay (Mahidol University) for helpful discussions and advice on NMR titration. The Science Achievement Scholarship of Thailand (SAST) is gratefully acknowledged for the financial support of K.K.

Reference: Kantarod, K.; Chakarawet, K.; Saekee, A.; Soorukram, D.; Kuhakarn, C.; Surawatanawong, P.; Reutrakul, V.; Leowanawat, P. Two-Heptagon Saddle-Shaped Nanographene as a Host for Fullerene Assembly. Org. Lett. 2025, 27, 13204-13210. DOI: https://doi.org/10.1021/acs.orglett.5c04019