Jump to navigation Jump to search Alkane metathesis is a class of chemical reaction in which an alkane is rearranged to give a longer or shorter alkane product. It is similar to olefin metathesisexcept that olefin metathesis cleaves and recreates a carbon-carbon double bond, but alkane methathesis operates on a carbon-carbon single bond.
The support can have an oxide moiety on the surface of the support. The metal can include tungsten, molybdenum, tantalum, zirconium, rhenium or vanadium. In each case, x, y and z maintain the d0 oxidation state of M. In certain embodiments, M can be tungsten or molybdenum. R1 can be methylidyne.
R2 can be methyl. In certain embodiments, M can be tantalum, or vanadium, R1 can be methylidyne. The catalyst can include both a monopodal species and a bipodal species.
In certain embodiments, M can be rhenium. In another aspect, a method of preparing a catalyst can include dehydroxylating a first material that includes an oxide in a heated environment and grafting the dehydroxylated first material with a second material that includes a moiety having a formula of MRx in an inert atmosphere, wherein M can be a group V or a group VI Alkane metathesis schrock in its highest oxidation state, R can be a C1-C4 alkyl group, and x can be an integer.
In certain embodiments, the first material can include an oxide of silicon, an oxide of aluminium, a mixed silica-alumina or an aminated oxide of silicon Si—NH2.
M can be tungsten, molybdenum, tantalum, or vanadium. R can be methyl.
The inert atmosphere can include argon. In another aspect, a method of converting alkanes into higher and lower homologues can include contacting a lower alkane or higher alkane or mixtures thereof with a catalyst comprising an oxide support and a supported metal alkyl species bound to the oxide support, wherein the supported metal alkyl species can be a group V or a group VI metal in its highest oxidation state and the alkyl group can be a C1-C4 alkyl.
The homologues are products that contain carbon chain lengths that are additive of the reactants. In other words, the products are metathesis products. Higher means compounds that contain 8 carbons or greater, for example, C8-C40 compounds.
Lower means compounds that contain fewer than 8 carbons, for example, C1-C7. The cycloalkane can undergo metathesis at a low temperature and in a single reaction vessel i. The metathesis products can be macrocycles, for example, hydrocarbon macrocycles having ring sizes of 12 to 40 carbons.
The method can include separating the higher and lower homologues into a single compound. In certain embodiments, the method includes halogenating the higher and lower homologues.
In certain circumstances, R1 and R2 can be a C1-C4 alkylidene group. In certain embodiments, M can be tungsten, or molybdenum. In certain embodiments, M can be tantalum, or vanadium. Other aspects, embodiments, and features will be apparent from the following description, the drawings, and the claims.
Exponential line broadening of 80 Hz was applied prior to Fourier transformation. The true sample temperatures were calibrated by separately measuring the 79Br isotropic chemical shifts and longitudinal relaxation times of KBr.
The number of scans was 20and the recycle delay was set to 5 s.This publication list was last updated on July 24, Visit the CENTC Google Scholar page for the most up to date list of publications and citations.
Inorganic Chemistry Cumulative Examination October 5, This cume is based the enclosed article in Science , Carbene complexes are the catalysts in olefin metathesis. There are Fischer- and Schrock-type carbene Briefly describe your understanding of why “the interconversion of alkanes via alkane metathesis is a reaction with.
During ISOM16, for which this special issue of Journal of Molecular Catalysis is devoted, the contributions of Grubbs and Schrock, our Nobels with Chauvin for , were devoted to alkene metathesis, as well as most of the other contributions from several authors, either looking at new and more efficient catalysts, in terms of both activity and tolerance to functional groups, or to their application in organic synthesis .
Read "Heterogeneous well-defined catalysts for metathesis of inert and not so inert bonds, Journal of Molecular Catalysis A: Chemical" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Professor Schrock at the Massachusetts Institute of Technology (MIT) fewer hydrogen atoms than their alkane equivalents.
While alkenes are still relatively stable, they are more reactive than their Olefin metathesis (OM) is the name given to the process in which. Metathesis reaction, in chemistry, a bimolecular process involving the exchange of bonds between the two reacting chemical species Olefin metathesis, an organic reaction which involves redistribution of olefinic (alkene) bonds; Alkane metathesis, a chemical reaction in which alkanes are rearranged to give longer or shorter alkane products.