Protonation of the Dodecahydro-closo-Dodecaborate Anion in CH3CN/CF3COOH

The behavior of the [B12H12]2– anion in CH3CN, CF3COOH, and the CH3CN/CF3COOH system is studied by IR spectroscopy. Based on the IR spectroscopy data correlated with the data obtained when studying the protonation processes of boron cluster anions [B6H6]2– and [B10H10]2–, the possibility to prepare the protonated form of the closo-dodecaborate anion, namely monoanion [B12H13]–, is concluded in CF3COOH and the CH3CN/CF3COOH system. In the IR spectra of salts of the protonated forms of anions [BnHn]2– (n = 6, 10, 12) in solutions and Nujol mulls, a high-frequency shift of the ν(BH) absorption bands is observed as compared with the spectra of salts of non-protonated anions Cat2[BnHn] (Δν = 70–100 cm–1).