Search results
Results from the WOW.Com Content Network
The vinyl cation is a carbocation with the positive charge on an alkene carbon. Its empirical formula of the parent ion is C 2 H + 3.Vinyl cation are invoked as reactive intermediates in solvolysis of vinyl halides, [1] [2] as well as electrophilic addition to alkynes and allenes.
In organic chemistry, vinylation is the process of attaching a vinyl group (CH 2 =CH−) to a substrate. Many organic compounds contain vinyl groups, so the process has attracted significant interest, especially since the reaction scope includes substituted vinyl groups. The reactions can be classified according to the source of the vinyl group.
Living cationic polymerization is a living polymerization technique involving cationic propagating species. [1] [2] It enables the synthesis of very well defined polymers (low molar mass distribution) and of polymers with unusual architecture such as star polymers and block copolymers and living cationic polymerization is therefore as such of commercial and academic interest.
A carbocation is an ion with a positively charged carbon atom. Among the simplest examples are the methenium CH + 3, methanium CH + 5, acylium ions RCO +, and vinyl C 2 H + 3 cations. [2] Until the early 1970s, carbocations were called carbonium ions. [3]
In 1984, Higashimura and Sawamoto reported the first living cationic polymerization for alkyl vinyl ethers. This type of polymerization has allowed for the control of well-defined polymers. A key characteristic of living cationic polymerization is that termination is essentially eliminated, thus the cationic chain growth continues until all ...
Polyvinyl chloride (PVC), a particular vinyl polymer; Vinyl cation, a type of carbocation; Vinyl group, a broad class of organic molecules in chemistry; Vinyl polymer, a group of polymers derived from vinyl monomers
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
In this case, the intermediate vinyl cation is formed by addition of HCl because it is resonance-stabilized by the phenyl group. Nevertheless, the lifetime of this high energy species is short, and the resulting vinyl cation-chloride anion ion pair immediately collapses, before the chloride ion has a chance to leave the solvent shell, to give ...