Lewis acid

These so-called Lewis acids readily form complexes with amines, phosphines, ethers, and halide ions. Examples of complex formation between boron trichloride and trimethylamine, as well as between boron trifluoride and fluoride ion, are shown in the following equations:

…(5) acid-base interactions in the Lewis acid-base sense—i.e., the affinity of electron-accepting species (Lewis acids) to electron donors (Lewis bases). The interplay of these forces and temperature are reflected in the partition coefficient and determine the order on polarity and eluotropic strength scales. In the special case of ions, a…

…pair, which is called a Lewis acid. In complexes of the formula [M(H₂O)₆]ⁿ⁺, the central metal ion acts as the Lewis acid and the ligand molecules act as the Lewis bases by virtue of a lone pair of electrons on the oxygen atom (only one of the lone pairs is…

…the other hand, the typical Lewis acids need not (and usually do not) contain protons, being species with outer electron shells that are capable of expansion, such as boron trifluoride (BF₃), sulfur trioxide (SO₃), and silver ion (Ag⁺). Lewis originally based his ideas on the experimental fact that these nonprotonic…

Much less information is available about Lewis acid–base equilibria than about ordinary acid–base equilibria, but it is clear that the situation is less simple for the former than for the latter. When a given Lewis acid reacts with a series of similarly constituted…