(Invited) Metallofullerenes, Fullerenes, and Fullertubes: Prediction of Structure Based on Anisotropic Polarizability and Chromatographic Retention Behavior

Today, computed structures of fullerenes and fullertubes are readily obtained from Fowler’s spiral program. 1 In addition, DFT parameters for fullerenes and fullertubes are readily calculated for these molecules, such as, UV-vis, Raman, and Polarizability. Especially important in this regard is their polarizability and anisotropic polarizability because they are related to the experimental HPLC chromatographic retention time and capacity factor, k′. Kappes and coworkers have mathematically described the effect of polarizabilities, dipole moments, and ionization potentials on these molecules. 2 For fullerenes and metallofullerenes, the polarizability is directly proportional to the experimental chromatographic retention parameter, ln(tr/to). Further work by Sabirov 3 indicates that anisotropic polarizability is an even better parameter for establishing subtle differences in fullerene structure. In 2021, Stevenson’s laboratory discovered a chemical separation approach that removes from consideration spheroidal and ellipsoidal fullerene cages leaving only tubular fullerenes or “fullertubes.” 4 In this presentation, we will show examples where structure determination can begin and end with chromatographic retention time data coupled with DFT calculated parameters for pristine fullertubes, C 100 -C 180. References: Fowler, Patrick W., and D. E. Manolopoulos. An Atlas of Fullerenes . Clarendon Press-Oxford, 1995. Fuchs, D.; Rietschel, H.; Michel, R. H.; Fischer, A.; Weis, P.; Kappes, M. M. Extraction and chromatographic elution behavior of endohedral metallofullerenes: Inferences regarding effective dipole moments. J. Phys. Chem. 1996, 100 (2), 725−72 Sabirov, D. S. The C 70 Fullerene Adducts with Low Anisotropy of Polarizability are More Efficient Electron Acceptors for Organic Solar Cells. The Minimum Anisotropy Hypothesis for Efficient Isomer-Free Fullerene-Adduct Photovoltaics. J. Phys. Chem. 2016, 120 (43), 24667−24674. Stevenson, S.; Liu, X.; Sublett, D. M., Jr; Koenig, R. M.; Seeler, T. L.; Tepper, K. R.; Franklin, H. M.; Wang, X.; Huang, R.; Feng, X.;et al, Semiconducting and Metallic [5,5] Fullertube Nanowires: Characterization of Pristine D 5h (1)-C 90 and D 5d (1)-C 100 . J. Am. Chem. Soc., 2021, 143 (12), 4593−4599.