ˈsuper-acid, a. and n.
Also super acid.
[super- 12 b.]
A. adj.
1. Chem. superacid salt = supersalt.
| 1808 Wollaston in Phil. Trans. XCVIII. 96 Other instances of super-acid and sub-acid salts. 1857 Miller Elem. Chem., Org. vi. §3. 425 A remarkable superacid salt (KO, 2HO, 2(C8H4O6) 3Aq). |
2. Excessively acid.
| 1901 in Dorland Med. Dict. |
3. Of, pertaining to, or designating a non-aqueous solution having very great protonating power.
| 1927 Conant & Hall in Jrnl. Amer. Chem. Soc. XLIX. 3047 We investigate certain of the properties of these solutions in which salt formation is exceptionally complete, and we propose to call such solutions ‘superacid solutions’. 1940 Glasstone Textbk. Physical Chem. xii. 959 On account of the very marked tendency of the CH3·CO2H2+ ions to lose the proton they have taken up from the acid, the solutions exhibit acidic properties, e.g., in catalysis, of an exceptionally strong nature and so they have been called super-acid. 1968 Accts. Chem. Res. I. 202/1 The acidity of fluorosulfuric acid can be considerably increased by the addition of SbF5 and SbF5{b1}SO3, and the resulting solutions are the most highly acidic media known... These systems may therefore be justifiably called superacid media. 1979 Science 5 Oct. 14/3 Two superacid systems used very frequently are HSO3F-SbF5 (Magic Acid)..and HF-SbF5 (fluoroantimonic acid). |
B. n. A solution of a strong acid in a very acidic solution, which is an extremely effective protonating agent; any acid stronger than some standard acid in either Brönsted acid (i.e., proton-donor) or Lewis acid (electron-acceptor) systems.
| 1968 Jrnl. Amer. Chem. Soc. XC. 2726/1 (caption) Chemistry in super acids. 1979 Science 5 Oct. 13/3 All protic acids stronger than 100 percent sulfuric acid should be classified as superacids. Ibid. 14/2 It is suggested that those [Lewis acids] stronger than anhydrous aluminum chloride..should be categorized as superacids. Ibid. 16/3 The astonishing acidity of Magic Acid and related superacids allows protonation of exceedingly weak bases. |
Hence superaˈcidic a. = super-acid a. 3.
| 1979 Science 5 Oct. 14/3 These superacidic systems can be 1016 times stronger than 100 per cent sulfuric acid. |