Premium
The Existence of Hexafluoroarsenic(V) Acid
Author(s) -
Axhausen Joachim,
Lux Karin,
Kornath Andreas
Publication year - 2014
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201308023
Subject(s) - hydrogen fluoride , anhydrous , chemistry , trimethylsilyl , hydrogen bond , molecule , crystal structure , fluoride , crystallography , antimony , decomposition , hydrogen , inorganic chemistry , polymer chemistry , medicinal chemistry , organic chemistry
The homogeneous mixture of anhydrous hydrogen fluoride a HF and antimony pentafluoride AsF 5 is known as a superacidic system. The high acidity is derived from the formation of [H 2 F] + [AsF 6 ] − . No experimental evidence exists for the existence of the free acid molecule HAsF 6 . The reaction of trimethylsilyl N , N ‐dimethylcarbamate in the binary system a HF/AsF 5 led to decomposition of trimethylsilyl N , N ‐dimethylcarbamate at −50 °C to dimethylammonium hexafluoridoarsenate and cocrystallization of HAsF 6 . The single‐crystal X‐ray structure displays an HAsF 6 molecule involved in an asymmetric hydrogen bridge to the hexafluoridoarsenate anion. As a result of the incalculable situation in the crystal lattice, the molecular structure of HAsF 6 is calculated by quantum chemical structure optimization of the extreme cases of [FHF‐AsF 5 ] − (strong hydrogen bond) and HAsF 6 (no hydrogen bond) at the PBE1PBE/6‐311G(3df,3pd) level of theory.