Experimental Determination of the Unusual CH Stretch Frequency of Protonated Fullerenes

Authors

Laura Finazzi, Radboud University
Vincent J. Esposito, Chapman UniversityFollow
Julianna Palotás, University of Edinburgh
Jonathan Martens, Radboud University
Els Peeters, University of Western Ontario
Jan Cami, University of Western Ontario
Giel Berden, Radboud University
Jos Oomens, Radboud University

Document Type

Article

Publication Date

8-16-2024

Abstract

We report experimental values for the CH stretch frequencies of the protonated fullerenes C₆₀H⁺ and C₇₀H⁺. Anharmonic frequency calculations at the B3LYP/6-31G level of theory, which are independent of empirical scaling factors, reproduce the experimental values to within approximately 5 cm⁻¹. Scaling theoretical harmonic frequencies by applying factors derived for polycyclic aromatic hydrocarbons deviate significantly from the experimentally measured frequency. We attribute this deviation to the unusual hydrocarbon structure that affects the degree of anharmonicity of the CH stretch. This result allows us to propose an original, specific scaling factor of 0.9524 to correct harmonic frequencies of CH stretches of protonated fullerenes calculated at the B3LYP/6-311 + G(d,p) level of theory. The special spectral position of the protonated fullerene CH stretch bands makes it a diagnostic marker that may aid in their detection in the interstellar medium.

Comments

This article was originally published in Astrophysical Journal, volume 971, in 2024. https://doi.org/10.3847/1538-4357/ad6302

Recommended Citation

Finazzi, L., Esposito V. J., Palotás J., Martens J., Peeters L., Cami J., Berden G., Oomens J. “Experimental Determination of the Unusual CH Stretch Frequency of Protonated Fullerenes.” Astrophys. J., 971, 68 (2024). https://doi.org/10.3847/1538-4357/ad6302

Copyright

The authors

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.