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It is named after Warren K. Lewis (1882–1975), [6] [7] who was the first head of the Chemical Engineering Department at MIT. Some workers in the field of combustion assume (incorrectly) that the Lewis number was named for Bernard Lewis (1899–1993), who for many years was a major figure in the field of combustion research. [citation needed]
In chemistry a donor number (DN) is a quantitative measure of Lewis basicity.A donor number is defined as the negative enthalpy value for the 1:1 adduct formation between a Lewis base and the standard Lewis acid SbCl 5 (antimony pentachloride), in dilute solution in the noncoordinating solvent 1,2-dichloroethane with a zero DN.
Lewis structure of a water molecule. Lewis structures – also called Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures (LEDs) – are diagrams that show the bonding between atoms of a molecule, as well as the lone pairs of electrons that may exist in the molecule.
The lone pair of electrons in such complexes is available for bonding, however, and therefore the complex itself can act as a Lewis base or ligand. This seen in the ferrocene-related product of the following reaction: SnCl 2 + Fe(η 5-C 5 H 5)(CO) 2 HgCl → Fe(η 5-C 5 H 5)(CO) 2 SnCl 3 + Hg
The Taft equation is a linear free energy relationship (LFER) used in physical organic chemistry in the study of reaction mechanisms and in the development of quantitative structure–activity relationships for organic compounds. It was developed by Robert W. Taft in 1952 [2] [3] [4] as a modification to the Hammett equation. [5]
Tin(II) 2-ethylhexanoate or tin(II) octoate or stannous octoate (Sn(Oct) 2) [1] is a compound of tin. Produced by the reaction of tin(II) oxide and 2-ethylhexanoic acid, it is a clear colorless liquid at room temperature, though often appears yellow due to impurities, likely resulting from oxidation of Sn(II) to Sn(IV).
Tin(II) bromide can act as a Lewis acid forming adducts with donor molecules e.g. trimethylamine where it forms NMe 3 ·SnBr 2 and 2NMe 3 ·SnBr 2 [11] It can also act as both donor and acceptor in, for example, the complex F 3 B·SnBr 2 ·NMe 3 where it is a donor to boron trifluoride and an acceptor to trimethylamine.
Competition experiment between SN2 and E2 With ethyl bromide , the reaction product is predominantly the substitution product. As steric hindrance around the electrophilic center increases, as with isobutyl bromide, substitution is disfavored and elimination is the predominant reaction.