Near-IR Photoluminescence of C₆₀⁺

Abstract

We have observed that C

Theoretical Rationalization of the Dual Photophysical Behavior of C60+

“…This Jahn-Teller effect is rather weak with a relaxation energy in the D5 state between the D5d and Ci structures of 0.063 eV and C-C bond lengths modifications not exceeding 0.02 Å. At this D5 minimum geometry, the vertical emission energy is computed at 1.242 eV, corresponding to an emission wavelength of 999 nm, in good agreement with the experimental value of 964.5 nm 24 (963.2 nm in the gas phase 15 ). An excellent agreement is obtained when considering the 0-0 transition energy, which is computed at 1.294 eV (958 nm).…”

“…This could also possibly explain the better agreement with the next absorption peaks observed between 910-930 nm in Ref. [24]. absorption spectrum in the NIR region with the FC (green line) and NE (red line) approaches.…”

“…Unlike the NIR photophysical pathway which leads to radiative decay, UV excitation at 405 and 375 nm does not lead to any detectable fluorescence. 24 Although we have computed up to 80 vertical transition energies, the excited states with an excitation wavelength lower than 500 nm suffer from a large spin contamination and are thus unreliable. Based on our TD-DFT calculations, it is therefore not possible to identify the electronic states that are initially populated by these UV excitations.…”

“…16,18,19,20,21,22,23 However, no information about the photophysics of C60 + had been reported until a very recent laboratory experiment investigated the photoluminescence of this cation. 24 The luminescence measurements show that C60 + trapped in a neon matrix at 5 K emits in the near-infrared (NIR) region at 964.5 nm upon excitation in the NIR at 785 nm but no detectable luminescence is obtained upon UV excitation at 405 and 375 nm. This study thus suggests to look for the characteristic NIR emission features of C60 + in astronomical environments, where either C60/C60 + has already been detected or fullerenes are likely to be present.…”

“…The vertical dashed line marks the computed 0-0 transition. The dashed blue line is the experimental spectrum digitalized from Ref [24]…”