For the most part, alkenes are a virtually stable compound that tend to react more then alkanes because of the presence of a carbon-carbon pi-bond. All most all of the alkene reactions involve the rupture of the pi-bond. This allows them to form new single bonds. Alkenes and alkene reactions are a vital part of the petrochemical industry because they are able to take part in a wide range of reactions. In the organic chemistry field, an alkene, olefine or olefin is an unsaturated chemical compound that contains at least one carbon to carbon double bond. In their simplest form, the acyclic alkenes have only one double bond with no other functional groups.
Of all the alkenes the most basic is ethylene, more commonly known as ethene. The name that is most widely used in the petrochemical industry is called olefins. Although the aromatic compounds are drawn as cyclic alkenes because of their structure and properties, they are not considered an alkene. By opening up the double bond, alkene reactions can react in a lot of addition reactions. By using hydrogen as the catalyst in an alkene reaction, it will produce alkanes. Alkanes are chemical compounds that are made up of only carbon and hydrogen. The addition alkene reactions take place under pressure, and with a metallic catalyst. The most common industrial catalysts are based on nickel, palladium and platinum. In laboratory synthesis Raney nickel is used. Raney nickel is an alloy made of aluminum and nickel. A simple example of an alkene reaction is the catalytic hydrogenation of ethylene to produce ethane.
Alkene reactions tend to be oxidized with a wide number of oxidizing agents. When they are in the presence of oxygen, alkenes will burn with a bright flame that will yield carbon dioxide and water. in order to produce epoxides with alkene reactions they must react with percarboxlic. When they react with ozone in ozonzlysis, the double bond will be broken, producing aldehydes or ketones.
Polymerization alkene reactions will produce polymers that hold a very industrial values. These alkene reactions produce such things as plastics – polyethylene and polypropylene. The polymers from alkenes monomers are broadly known as polyolefin’s or polyalkenes. This polymerization can move forward with either a free radical or an ionic mechanism. They transform the double bond to a single bond which join the monomers.
An important method for alkene reactions involving synthesis take pace via the construction of a new carbon-carbon double bond by the combining of a carbonyl compound like aldehyde or ketone, to be a carbonion equal. These alkene reactions are also called olefinations with the most common being the Wittings reaction method. The Wittig reaction encompasses the reaction of an aldehyde or ketone with a Wittig reagent that will yield an alkene, This method is very basic and a multitude of functional groups are accepted. Closely related to the Wittig reaction is the Peterson olefination which uses a less accessible silicon reagent in the place of phosphorane. Another alkene reaction uses the Julia olefination. It uses a carbannion that is made from phenyl sulfane. |
