IR Absorptions of C₆₀⁺ and C₆₀^– in Neon Matrixes

Abstract

C₆₀⁺ ions\nwere produced by electron-impact ionization of sublimed C₆₀, collimated into an ion beam, turned 90° by an electrostatic\ndeflector to separate them from neutrals, mass filtered by a radio\nfrequency quadrupole, and co-deposited with Ne on a cold 5 K gold-coated\nsapphire substrate. Infrared absorption spectroscopy revealed the\nadditional presence of C₆₀ and C₆₀^– in the as-prepared cryogenic\nmatrixes. To change the C₆₀⁺/C₆₀^– ratio, CCl₄ or CO₂ electron scavengers were added to the matrix gas. Also taking into\naccount DFT calculations, we have identified nine new previously unpublished\nIR absorptions of C₆₀⁺ and seven of C₆₀^– in Ne matrixes. Our measurements are in very good\nagreement with DFT calculations, predicting <i>D</i>_5<i>d</i> C₆₀⁺ and <i>D</i>_3<i>d</i> C₆₀^– ground states. The new results may be of interest regarding the\npresence of C₆₀ and C₇₀ (as well as ions thereof)\nin Space.