文摘
Cb class="stack">70b>+ ions were mass-selectively deposited into a neon or an argon matrix at 5 K. Like in the case of Cb class="stack">60b>+ deposition, soft landing into a rare gas matrix is associated with some charge-exchange processes such that Cb class="stack">70b>+ as well as resulting Cb>70b> and Cb class="stack">70b>– can be probed simultaneously. In contrast with a very good coincidence of the experimental and DFT-calculated IR spectra of Cb class="stack">60b>±/2+, DFT predictions for Cb class="stack">70b>± IR absorptions strongly deviate from our measurements. A possible explanation for this could be low-lying electronically excited states of Cb class="stack">70b>± in the vicinity of vibrational energy levels. The corresponding non-Born–Oppenheimer case is likely of significant interest to theory.