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The Strongest Acid: Protonation of Carbon Dioxide
Author(s) -
Cummings Steven,
Hratchian Hrant P.,
Reed Christopher A.
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201509425
Subject(s) - protonation , chemistry , lewis acids and bases , adduct , carborane , base (topology) , acid–base reaction , brønsted–lowry acid–base theory , medicinal chemistry , proton , carbon dioxide , organic base , inorganic chemistry , catalysis , organic chemistry , ion , mathematical analysis , physics , mathematics , quantum mechanics
The strongest carborane acid, H(CHB 11 F 11 ), protonates CO 2 while traditional mixed Lewis/Brønsted superacids do not. The product is deduced from IR spectroscopy and calculation to be the proton disolvate, H(CO 2 ) 2 + . The carborane acid H(CHB 11 F 11 ) is therefore the strongest known acid. The failure of traditional mixed superacids to protonate weak bases such as CO 2 can be traced to a competition between the proton and the Lewis acid for the added base. The high protic acidity promised by large absolute values of the Hammett acidity function ( H 0 ) is not realized in practice because the basicity of an added base is suppressed by Lewis acid/base adduct formation.