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Lewis acidity

المؤلف:  Peter Atkins, Tina Overton, Jonathan Rourke, Mark Weller, and Fraser Armstrong

المصدر:  Shriver and Atkins Inorganic Chemistry ,5th E

الجزء والصفحة:  ص131-132

2025-08-25

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Lewis acidity

Key points: ALewis acid is an electron pair acceptor; a Lewis base is an electron pair donor. The Brønsted–Lowry theory of acids and bases focuses on the transfer of a proton between species. The solvent system generalizes the Brønsted–Lowry theory to include the transfer of cationic and anionic species other than protons. Whereas both definitions are more general than any that preceded them, they still fail to take into account reactions between substances that show similar features but in which no proton or other charged species is transferred. This deficiency was remedied by a more general theory of acidity introduced by G.N. Lewis in the same year as Brønsted and Lowry introduced theirs (1923). Lewis’s approach became influential only in the 1930s. ALewis acid is a substance that acts as an electron pair acceptor. A Lewis base is a sub stance that acts as an electron pair donor. We denote a Lewis acid by A and a Lewis base by: B, often omitting any other lone pairs that may be present. The fundamental reaction of Lewis acids and bases is the formation of a complex (or adduct), A–B, in which A and: B bond together by sharing the electron pair supplied by the base.