2025ApJ...993...47G

The fullerenes C₆₀ and C₇₀ have been detected in various interstellar environments, and the cation ${{{\rm{C}}}_{60}}^{+}$ has been identified as a carrier of at least four of the diffuse interstellar bands (DIBs). Based on the presence of fullerenes in space, it is plausible that certain fullerene analogs are abundant in interstellar environments as well. In this context, we present the first electronic laboratory spectra of the analogs C₆₀H₂O⁺, C₆₀H⁺, C₆₀D⁺, and C₆₀Mg⁺. Furthermore, the electronic ${{{\rm{C}}}_{60}}^{+}$ spectrum is remeasured and assignments of the observed transitions are proposed. In the spectrum of C₆₀H₂O⁺, several distinct absorption features could be detected between 10,300 and 10,800 cm^–1, whereas the analogs C₆₀H⁺, C₆₀D⁺, and C₆₀Mg⁺ show a broad absorption in the visible region between 17,000 and 25,000 cm^–1. None of the detected absorption features in these analogs of ${{{\rm{C}}}_{60}}^{+}$ could be assigned to DIBs.