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A hydroxide ion acting as a nucleophile in an S N 2 reaction, converting a haloalkane into an alcohol. In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they ...
The terms nucleophile and electrophile are sometimes interchangeable with Lewis base and Lewis acid, respectively. These terms, especially their abstract noun forms nucleophilicity and electrophilicity , emphasize the kinetic aspect of reactivity, while the Lewis basicity and Lewis acidity emphasize the thermodynamic aspect of Lewis adduct ...
Alkali metal phenolates, such as sodium phenolate hydrolyze in aqueous solution to form basic solutions. [2] At pH = 10, phenol and phenolate are in approximately 1:1 proportions. The phenoxide anion (aka phenolate) is a strong nucleophile with a comparable to the one of carbanions or tertiary amines. [3]
The rate equation for S N 2 reactions are bimolecular being first order in Nucleophile and first order in Reagent. The determining factor when both S N 2 and S N 1 reaction mechanisms are viable is the strength of the Nucleophile. Nuclephilicity and basicity are linked and the more nucleophilic a molecule becomes the greater said nucleophile's ...
For example, OH − is a better nucleophile than water, and I − is a better nucleophile than Br − (in polar protic solvents). In a polar aprotic solvent, nucleophilicity increases up a column of the periodic table as there is no hydrogen bonding between the solvent and nucleophile; in this case nucleophilicity mirrors basicity.
Organometallic compounds of electropositive metals are superbases, but they are generally strong nucleophiles. Examples include organolithium and organomagnesium ( Grignard reagent ) compounds. Another type of organometallic superbase has a reactive metal exchanged for a hydrogen on a heteroatom , such as oxygen (unstabilized alkoxides ) or ...
The nucleophile may be electrically neutral or negatively charged, whereas the substrate is typically neutral or positively charged. An example of nucleophilic substitution is the hydrolysis of an alkyl bromide, R-Br under basic conditions, where the attacking nucleophile is hydroxyl (OH −) and the leaving group is bromide (Br −).
As nucleophiles, organolithium reagents undergo carbolithiation reactions, whereby the carbon-lithium bond adds across a carbon–carbon double or triple bond, forming new organolithium species. [32] This reaction is the most widely employed reaction of organolithium compounds.