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Acid strength is the tendency of an acid, symbolised by the chemical formula ... Two key factors that contribute to the ease of deprotonation are the polarity of the ...
For example, deprotonation of an alcohol forms the negatively charged alkoxide, which is a much stronger nucleophile. To determine whether or not a given base will be sufficient to deprotonate a specific acid, compare the conjugate base with the original base. A conjugate base is formed when the acid is deprotonated by the base.
For the deprotonation of acids, K is known as K a, the acid dissociation constant. Strong acids, such as sulfuric or phosphoric acid , have large dissociation constants; weak acids, such as acetic acid , have small dissociation constants.
The starting point for the collection of the substituent constants is a chemical equilibrium for which the substituent constant is arbitrarily set to 0 and the reaction constant is set to 1: the deprotonation of benzoic acid or benzene carboxylic acid (R and R' both H) in water at 25 °C. Scheme 1. Dissociation of benzoic acids
In chemistry, an acid dissociation constant (also known as acidity constant, or acid-ionization constant; denoted ) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction
Interaction of triethylphosphine oxide with a Lewis acid Boron trihalides are archetypal Lewis acids and have AN values between 89 (BF 3 ) and 115 (BI 3 ). [ 2 ] The Gutmann–Beckett method has been applied to fluoroarylboranes [ 7 ] [ 8 ] such as B(C 6 F 5 ) 3 (AN 82), and borenium cations, and its application to these and various other boron ...
This generates a complex-induced proximity effect, which directs deprotonation at the α position to form an aryllithium species that can further react with electrophiles. Some of the most effective DMGs are amides, carbamates, sulfones and sulfonamides. They are strong electron-withdrawing groups that increase the acidity of alpha-protons on ...
The Hammett acidity function (H 0) is a measure of acidity that is used for very concentrated solutions of strong acids, including superacids.It was proposed by the physical organic chemist Louis Plack Hammett [1] [2] and is the best-known acidity function used to extend the measure of Brønsted–Lowry acidity beyond the dilute aqueous solutions for which the pH scale is useful.