Lewis base

American

noun

Chemistry.

any substance capable of forming a covalent bond with an acid by transferring a pair of electrons to it.

Lewis base British

noun

a substance capable of donating a pair of electrons to an acid to form a covalent bond Compare Lewis acid

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of Lewis base

First recorded in 1960–65; named after G. N. Lewis

Example Sentences

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Lewis base

Being short of the preferred octet, BF3 is a very good Lewis acid and reacts with many Lewis bases; a fluoride ion is the Lewis base in this reaction, donating one of its lone pairs:

From Textbooks ● Feb. 14, 2019

The Lewis base donors, called ligands, can be a wide variety of chemicals—atoms, molecules, or ions.

From Textbooks ● Feb. 14, 2019

Ammonia acts as a Brønsted base because it readily accepts protons and as a Lewis base in that it has an electron pair to donate.

From Textbooks ● Feb. 14, 2019

Identify the Lewis acid and the Lewis base among the reactants.

From Textbooks ● Feb. 14, 2019

The species donating the electron pair that compose the bond is a Lewis base, the species accepting the electron pair is a Lewis acid, and the product of the reaction is a Lewis acid-base adduct.

From Textbooks ● Feb. 14, 2019

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023