Excitations, Optical Absorption Spectra, and Optical Excitonic Gaps of Heterofullerenes: I. C60, C59N+ and C48N12

Published

October 16, 2008

Author(s)

Rui-Hua Xie, Garnett W. Bryant, G Sun, M C. Nicklaus, V H. Smith, Y Araki, O Ito

Abstract

Low-energy excitations and optical absorption spectrum of C₆₀ are computed by using time-dependent (TD) density functional theory (DFT). A detailed comparison of experiment and theory for the excitation energies, optical gap and absorption spectrum of C₆₀ is presented. It is found that the TD-DFT method with non-hybrid functional or a local spin density approximation agreement between theory and experiment for C₆₀ justifies similar calculations of the excitations and optical absorption spectrum of a monomeric azafullerene cation C₅₉N⁺, to serve as a reference and explain our measured ultraviolet-visible (UV-vis) and transient absorption spectra of the carborane anion salt [C59N][Ag(CB₁₁H₆Cl₆)₂] [K.C. kim, F. Hauke, A. Hirch, P.D.W. Boyd, E. Carter, R.S. Armstrong, P.A. Lay, and C.A. Reed, J. Am. Chem. Soc. 125, 4024 (2003)]. Although it is an isoelectronic analogue to C₆₀, C₅₉N⁺ exhibits distinguishing spectral features: visible region; (3) the transient absorption spectrum is much broader and the decay of the triplet state is much faster. For the most stable isomer of C₄₈N₁₂, we predict that the first singlet is dipole-allowed, the optical gap is redshifted by 1.22 eV relative to that of C_{60, and optical absorption maxima occur at 585, 528, 443, 363, 340, 314 and 303 nm. We point out that the characterization of the UV-vis and transient absorption spectra of C}d48^N₁₂ isomers is helpful in distinguishing the isomer structures required for applications in molecular electronics.

Citation

Journal of Chemical Physics

Volume

120

Pub Type

Journals

Keywords

Ab initio, azafullerene, C₆₀, excited state, hartee-fock, molecular electronics, TD-DFT, UV-vis-NIR spectrum, ZINDO

Citation

Xie, R. , Bryant, G. , Sun, G. , Nicklaus, M. , Smith, V. , Araki, Y. and Ito, O. (2008), Excitations, Optical Absorption Spectra, and Optical Excitonic Gaps of Heterofullerenes: I. C₆₀, C₅₉N⁺ and C₄₈N₁₂, Journal of Chemical Physics (Accessed April 19, 2024)