The process described is an equilibrium between two equivalents of an alkyl or aryl magnesium halide on the left of the equation and on the right side, one equivalent of the dialkyl or diaryl magnesium compound and magnesium halide salt. Organomagnesium halides in solution also form dimers and higher oligomers, especially at high concentration. Alkyl magnesium chlorides in ether are present as dimers.[5]
The position of the equilibrium is influenced by solvent, temperature, and the nature of the various substituents. It is known that magnesium center in Grignard reagents typically coordinates two molecules of ether such as diethyl ether or tetrahydrofuran (THF). Thus they are more precisely described as having the formula RMgXL2 where L = an ether. In the presence of monoethers, the equilibrium typically favors the alkyl- or arylmagnesium halide. Addition of dioxane to such solutions, however, leads to precipitation of the coordination polymers MgX2(μ-dioxane)2,[6] driving the equilibrium completely to the right. [7] The dialkylmagnesium compounds are popular in the synthesis of organometallic compounds.
Referencesedit
^W. Schlenk; W. Schlenk, Jr. (1929). "Über die Konstitution der Grignardschen Magnesiumverbindungen". Chem. Ber.62 (4): 920. doi:10.1002/cber.19290620422.
^Grignard Reagents: New Developments H. G. Richey (Editor) ISBN0-471-99908-3
^ Neufeld, R.: DOSY External Calibration Curve Molecular Weight Determination as a Valuable Methodology in Characterizing Reactive Intermediates in Solution. In: eDiss, Georg-August-Universität Göttingen. 2016.
^Neufeld, R.; Teuteberg, T. L.; Herbst-Irmer, R.; Mata, R. A.; Stalke, D. (2016). "Solution Structures of Hauser Base iPr2NMgCl and Turbo-Hauser Base iPr2NMgCl·LiCl in THF and the Influence of LiCl on the Schlenk-Equilibrium". J. Am. Chem. Soc.138 (14): 4796–4806. doi:10.1021/jacs.6b00345. PMID 27011251.
schlenk, equilibrium, named, after, discoverer, wilhelm, schlenk, chemical, equilibrium, taking, place, solutions, grignard, reagents, hauser, bases, rmgx, mgx2, mgr2, process, described, equilibrium, between, equivalents, alkyl, aryl, magnesium, halide, left,. The Schlenk equilibrium named after its discoverer Wilhelm Schlenk is a chemical equilibrium taking place in solutions of Grignard reagents 1 2 and Hauser bases 3 4 2 RMgX MgX2 MgR2 The process described is an equilibrium between two equivalents of an alkyl or aryl magnesium halide on the left of the equation and on the right side one equivalent of the dialkyl or diaryl magnesium compound and magnesium halide salt Organomagnesium halides in solution also form dimers and higher oligomers especially at high concentration Alkyl magnesium chlorides in ether are present as dimers 5 The position of the equilibrium is influenced by solvent temperature and the nature of the various substituents It is known that magnesium center in Grignard reagents typically coordinates two molecules of ether such as diethyl ether or tetrahydrofuran THF Thus they are more precisely described as having the formula RMgXL2 where L an ether In the presence of monoethers the equilibrium typically favors the alkyl or arylmagnesium halide Addition of dioxane to such solutions however leads to precipitation of the coordination polymers MgX2 m dioxane 2 6 driving the equilibrium completely to the right 7 The dialkylmagnesium compounds are popular in the synthesis of organometallic compounds References edit W Schlenk W Schlenk Jr 1929 Uber die Konstitution der Grignardschen Magnesiumverbindungen Chem Ber 62 4 920 doi 10 1002 cber 19290620422 Grignard Reagents New Developments H G Richey Editor ISBN 0 471 99908 3 Neufeld R DOSY External Calibration Curve Molecular Weight Determination as a Valuable Methodology in Characterizing Reactive Intermediates in Solution In eDiss Georg August Universitat Gottingen 2016 Neufeld R Teuteberg T L Herbst Irmer R Mata R A Stalke D 2016 Solution Structures of Hauser Base iPr2NMgCl and Turbo Hauser Base iPr2NMgCl LiCl in THF and the Influence of LiCl on the Schlenk Equilibrium J Am Chem Soc 138 14 4796 4806 doi 10 1021 jacs 6b00345 PMID 27011251 J March Advanced Organic Chemistry 3rd Ed ISBN 0 471 85472 7 Fischer Reinald Gorls Helmar Meisinger Philippe R Suxdorf Regina Westerhausen Matthias 2019 Structure Solubility Relationship of 1 4 Dioxane Complexes of Di hydrocarbyl magnesium Chemistry A European Journal 25 55 12830 12841 doi 10 1002 chem 201903120 PMC 7027550 PMID 31328293 Richard A Andersen Geoffrey Wilkinson 1979 Bis Trimethylsilyl Methyl Magnesium Inorganic Syntheses Vol 19 pp 262 265 doi 10 1002 9780470132500 ch61 ISBN 9780470132500 a href Template Cite book html title Template Cite book cite book a journal ignored help Retrieved from https en wikipedia org w index php title Schlenk equilibrium amp oldid 1173818626, wikipedia, wiki, book, books, library,
