Alpha-olefinIn organic chemistry, alpha-olefins (or α-olefins) are a family of organic compounds which are alkenes (also known as olefins) with a chemical formula , distinguished by having a double bond at the primary or alpha (α) position. This location of a double bond enhances the reactivity of the compound and makes it useful for a number of applications. There are two types of alpha-olefins, branched and linear (or normal).
DehydrogenationIn chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At its simplest, it is useful way of converting alkanes, which are relatively inert and thus low-valued, to olefins, which are reactive and thus more valuable. Alkenes are precursors to aldehydes (), alcohols (), polymers, and aromatics.
Olefin metathesisOlefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds. Because of the relative simplicity of olefin metathesis, it often creates fewer undesired by-products and hazardous wastes than alternative organic reactions. For their elucidation of the reaction mechanism and their discovery of a variety of highly active catalysts, Yves Chauvin, Robert H. Grubbs, and Richard R.
Zeise's saltZeise's salt, potassium trichloro(ethylene)platinate(II) hydrate, is the chemical compound with the formula K[PtCl3(C2H4)]·H2O. The anion of this air-stable, yellow, coordination complex contains an η2-ethylene ligand. The anion features a platinum atom with a square planar geometry. The salt is of historical importance in the area of organometallic chemistry as one of the first examples of a transition metal alkene complex and is named for its discoverer, William Christopher Zeise.
MetalloceneA metallocene is a compound typically consisting of two cyclopentadienyl anions (C5H5−, abbreviated Cp) bound to a metal center (M) in the oxidation state II, with the resulting general formula (C5H5)2M. Closely related to the metallocenes are the metallocene derivatives, e.g. titanocene dichloride or vanadocene dichloride. Certain metallocenes and their derivatives exhibit catalytic properties, although metallocenes are rarely used industrially. Cationic group 4 metallocene derivatives related to [Cp2ZrCH3]+ catalyze olefin polymerization.
Organyl groupIn organic and organometallic chemistry, an organyl group is an organic substituent with one (sometimes more) free valence(-s) at a carbon atom. The term is often used in chemical patent literature to protect claims over a broad scope. Acetonyl group Acyl group (e.g. acetyl group, benzoyl group) Alkyl group (e.g., methyl group, ethyl group) Alkenyl group (e.g.
TriethylaluminiumTriethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name the compound has the formula Al2(C2H5)6 (abbreviated as Al2Et6 or TEA). This colorless liquid is pyrophoric. It is an industrially important compound, closely related to trimethylaluminium. The structure and bonding in Al2R6 and diborane are analogous (R = alkyl). Referring to Al2Me6, the Al-C(terminal) and Al-C(bridging) distances are 1.97 and 2.14 Å, respectively. The Al center is tetrahedral.
Homologous seriesIn organic chemistry, a homologous series is a sequence of compounds with the same functional group and similar chemical properties in which the members of the series can be branched or unbranched, or differ by molecular formula of and molecular mass of 14u. This can be the length of a carbon chain, for example in the straight-chained alkanes (paraffins), or it could be the number of monomers in a homopolymer such as amylose. Compounds within a homologous series typically have a fixed set of functional groups that gives them similar chemical and physical properties.
Hofmann eliminationHofmann elimination is an elimination reaction of an amine to form alkenes. The least stable alkene (the one with the fewest substituents on the carbons of the double bond), called the Hofmann product, is formed. This tendency, known as the Hofmann alkene synthesis rule, is in contrast to usual elimination reactions, where Zaitsev's rule predicts the formation of the most stable alkene. It is named after its discoverer, August Wilhelm von Hofmann.
Vicinal (chemistry)In chemistry the descriptor vicinal (from Latin vicinus = neighbor), abbreviated vic, describes any two functional groups bonded to two adjacent carbon atoms (i.e., in a 1,2-relationship). For example, the molecule 2,3-dibromobutane carries two vicinal bromine atoms and 1,3-dibromobutane does not. Mostly, the use of the term vicinal is restricted to two identical functional groups. Likewise in a gem-dibromide the prefix gem, an abbreviation of geminal, signals that both bromine atoms are bonded to the same atom (i.
