The Protonation of Acetamide and Thioacetamide in Superacidic Solutions: Crystal Structures of [H 3 CC(OH)NH 2 ] + AsF 6 – and [H 3 CC(SH)NH 2 ] + AsF 6 –

Acetamide and thioacetamide react with the superacid solutions HF/MF 5 (M = As, Sb) under formation of the corresponding salts [H 3 CC(OH)NH 2 ] + MF 6 – and [H 3 CC(SH)NH 2 ] + MF 6 – (M = As, Sb), respectively. The reaction of DF/AsF 5 with acetamide and thioacetamide lead to the corresponding deuterated salts [H 3 CC(OD)ND 2 ] + AsF 6 – and [H 3 CC(SD)ND 2 ] + AsF 6 – , respectively . The salts are characterized by vibrational and NMR spectroscopy, and in the case of [H 3 CC(OH)NH 2 ] + AsF 6 – and [H 3 CC(SH)NH 2 ] + AsF 6 – also by single‐crystal X‐ray analyses. The [H 3 CC(OH)NH 2 ] + AsF 6 – ( 1 ) salt crystallizes in the triclinic space group P $\bar{1}$ with two formula units per unit cell, and the [H 3 CC(SH)NH 2 ] + AsF 6 – ( 2 ) salt crystallizes in the monoclinic space group P 2 1 / c with four formula units per unit cell. In both crystal structures three‐dimensional networks are observed which are formed by intra‐ and intermolecular N–H ··· F and O–H ··· F or S–H ··· F hydrogen bonds, respectively. For the vibrational analyses, quantum chemically calculated spectra of the cations [H 3 CC(OH)NH 2 · 3HF] + and [H 3 CC(SH)NH 2 · 2HF] + are considered.