(Invited) Is the [5,5] C120-D5d Fullertube a Metal?

Le résumé fourni par la source

Single-walled nanotubes (SWNTs) with a roll-up vector (n = m) have long been predicted to exhibit metallic behavior at infinite nanotube lengths.1 Moreover, in contrast with normal metals, armchair nanotubes e.g., [5,5] should result in exceptional ballistic transport properties.2 However, the question remains at what finite length of a SWNT or fullertube does metallic character begin, if at all. From a computational viewpoint, Cioslowski has shown that the HOMO-LUMO bandgap decreases to ~1 eV in an oscillatory fashion in approaching [5,5] C200 fullertubes.3 Although the HOMO-LUMO gap has been extensively used to predict the kinetic stability of fullerenes and metallofullerenes with less than 100 carbon atoms, Fowler has argued that the HOMO-LUMO gap can not be used to predict the kinetic stability of large fullerenes.4 More recently, Lilijeroth and coworkers have measured the experimental and DFT HOMO-LUMO gap for graphene nanoribbons (GNR) and find that GNRs with lengths of 5 nm have bandgaps of ~0.1 eV.5 These workers also point out that DFT calculated HOMO-LUMO bandgaps are always overestimated relative to experimental values. In this presentation, I will present the evidence in support of metallic character for [5,5] C120-D5d.6,7 References: 1. Mintmire, J. W.; Dunlap, B. I.; White, C. T. Are Fullerene Tubules Metallic? Phys. Rev. Lett. 1992, 68, 631−634. 2. White, C. T.; Todorov, T. N. Carbon Nanotubes as Ballistic Conductors. Nature 1998, 393, 240−242. 3. Cioslowski, J.; Rao, N.; Moncrieff, D. Electronic Structures and Energetics of [5,5] and [9,0] Single-Walled Carbon Nanotubes. J. Am. Chem. Soc. 2002, 124 (28), 8485−8489. 4. Fowler, P., Nature (London), 1991, 350, 20. 5. Kimouche, A., Ervasti, M. M., Drost, R., Halonen, S., Harju, A,. Joensuu, M. P., Sainio, J., Liljeroth P., Ultra-narrow metallic armchair graphene nanoribbons. Nature Communications, 2015, 6 (1) 1-5. 6. 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 D5h(1)-C90 and D5d(1)-C100. J. Am. Chem. Soc. 2021, 143 (12), 4593−4599. 7. Liu, X.; Bourret, E.; Noble, C. A.; Cover, K.; Koenig, R. M.; Huang, R.; Franklin, H. M.; Feng, X.; Bodnar, R. J.; Zhang, F.; et al. Gigantic C120 Fullertubes: Prediction and Experimental Evidence for Isomerically Purified Metallic [5,5] C120-D5d(1) and Nonmetallic [10,0] C120-D5h(10766). J. Am. Chem. Soc. 2022, 144 (36), 16287−16291.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.