Protonation of Pyruvic Acid – Synthesis of a plain Superelectrophile

• Published in: Zeitschrift für anorganische und allgemeine Chemie (1950) Vol. 648; no. 14
• Main Authors: Virmani, Alan, Pfeiffer, Martina, Jessen, Christoph, Morgenstern, Yvonne, Kornath, Andreas J.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 27-07-2022
• Subjects: Crystal structure; Protonation; quantum chemical calculations; Quantum chemistry; superacidic systems; superelectrophiles; vibrational spectroscopy; X-ray diffraction
• ISSN: 0044-2313; 1521-3749
• DOI: 10.1002/zaac.202200005

The syntheses of [H3C(O)CC(OH)2][MF6] and [H3C(OH)CC(OH)2][MF6]2 (M=As, Sb) by reacting pyruvic acid in the superacidic systems HF/AsF5 and HF/SbF5 are reported. The salts were characterized by low‐temperature vibrational spectroscopy and in the cases of [H3C(O)CC(OH)2][SbF6] and [H3C(OH)CC(OH)2][SbF6]2 ⋅ HF by X‐ray crystal structure analyses. The experimental results are discussed together with quantum chemical calculations. Remarkably, the bond distance and the twisting angle around the central C−C bond are unaffected by the protonations despite increasing coulombic repulsion. The crystal structure reveals short interionic interactions that have a considerable influence on the C−C bond.