Lewis base


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Lewis base


[After Gilbert Lewis.]

Lewis base

n
(Elements & Compounds) a substance capable of donating a pair of electrons to an acid to form a covalent bond. Compare Lewis acid
[C20: named after G. N. Lewis (1875–1946), US chemist]
Translations
base de Lewis
References in periodicals archive ?
Analysis of the obtained data on the distribution of the adsorption centers on the surface of saponite indicates the predominance of Bronsted base sites (pK = 7.6, pK = 12.8) and Lewis base sites (pK = -0.29), as well as a small number of Bronsted acid sites (pK = 2.1, pK = 5.25).
In addition, the active carbocation is stabilized through interactions with the counter anion and/or interactions with Lewis base additives present in the polymerization system.
Generally halogen bonding is of two types, (i) halogen halogen interaction X X which is due to anisotropic distribution of electron density among halogen atoms, (ii) halogen lewis base interaction X AX.
Carbon dioxide also has several other favorable advantages including: being a quadrupolar solvent; having the potential to act as both a weak Lewis acid and Lewis base; being able to be easily removed, enabling rapid recovery of isolated compounds; and, when used for SFC, it can be recovered from the atmosphere, making it a "green" solvent.
The process comprises a polymerization step, wherein a conjugated diene polymer having a cis-1,4-bond content of 98.5 mass % or more and a ratio (Mw/ Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography of 2.5 or less is obtained by carrying out a polymerization reaction in conjugated diene compounds using a catalyst composition containing a rare earth element-containing compound or a reaction product of the rare earth element-containing compound with a Lewis base, an aluminoxane and/or organoaluminum compound, and an iodine-containing compound.
The dissociation of calcium carbonate in water is well known -- exhibiting associated Lewis base sites with various dissociation complexes including significant ionic species that are formed in situ ([H.sup.+], O[H.sup.-], [C[a.sub.2].sup.+], [C[O.sup.2-].sub.3], [HC[O.sup.-].sub.3] and [CaHC[O.sup.+].sub.3]).
Their frustrated pair comprised of the Lewis base tetramethylpiperidine or TMP and the Lewis acid tris(pentafluorophenyl)borane.
Tomoaki Iishiba, 34, who served as an intelligence liaison officer at the Army's Fort Lewis base in Washington state, allegedly conspired with a partner from around 2006 through February 2008 to purchase night-vision sights and gun parts from a company in Illinois and export them to Japan without obtaining U.S.
Supporters of the Quiggins store yesterday staged a protest outside the John Lewis base on Church Street and collected 5,000 signatures from the public.
Tertiary amines also use a Lewis base mechanism which increases the nucleophilic properties of the alcohol compound.
So did Lewis base camel-faced Sebulba on any of the people he impersonates?

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