Metathesis reaction, mixed-metal

The metathesis reaction of metal chloride with alkali alkoxides (method 5) was historically the first approach applied, and it remains the main route to both mono- and bimetallic derivatives of Mn(H). The most efficient approach to Mn(II) derivatives is, however, provided by the alcoholysis of the corresponding silylamide (method 4). The derivatives of Mn(IH) and mixed-valence Mn(H,IH) were obtained by alcoholysis ofMn(III) acetate by polyatomic phenols in the presence of 2,2 -dipyridil accompanied by reduction in the latter case (methods 4 and 4+7). 

One attractive feature of alanates is that lithium and sodium salts are readily available commercially. Magnesium alanate can be readily prepared with sodium alanate and magnesium hydride via a metathesis reaction. The mixed metal alanate, Na2LiAlH6, is prepared through ball milling of sodium hydride, lithium hydride, and sodium alanate. Potassium alanate can be prepared by the direct synthesis of potassium hydride and aluminum under high temperature and pressure." ... 

The 2005 Nobel Prize in Chemistry was jointly awarded to Robert H. Grubbs (Caltech), Yves Chauvin (French Petroleum Institute), and Richard R. Schrock (MIT) for establishing olefin metathesis as a reaction of synthetic versatility and contributing to an understanding of the mechanism of this novel process. Olefin metathesis first surfaced in the late 1950s when industrial researchers found that alkenes underwent a novel reaction when passed over a heated bed of mixed metal oxides. Propene, for example, was converted to a mixture of ethylene and 2-butene (cis + trans). 

In a ical polymerization using metathesis catalysts, the metal salt and the cocatalysts were mixed together in an organic solvent followed by an aging period. If no cocatalyst was used, the cat-afyst required no aging and was used directly. Subsequent, the substituted acetylene monomer was added, and the extent of conversion was monitored by gas chromatography. The reaction was typically terminated with a mixture of toluene and methanol (5 1 by volume). The reaction mixture was then poured into MeOH to precipitate the polymers. 

Chemistry may have found an answer. Sandia National Labs in the United States have developed a cheap mixture of ammonium nitrate and iron sulfate which is a cheap and effective fertilizer, but which, crucially, when mixed with fuel oil does not become an ANFO explosive. As soon as the mixture is mixed with a solvent, such as fuel oil, a metathesis reaction occurs and the two metal ions... 

Preparation of Mixed-Metal Carbonyls by Metathesis Reaction... 

The following reaction between cobalt and ruthenium carbonyl uses metathesis to obtain a mixed metal complex ... 

Heterobimetallic complexes in which a half-sandwich complex of rhodium ill) is cormected by three bromo-bridges to Re(CO)3 were prepared from metathesis reactions of [Cp RhBr2]2 and [Re( -Br)(C0)3(C4H80)]2- The crystal structure of Cp Rh(/t-Br)3Re(CO)3 was determined by X-ray analysis. The treatment of a mixture of [(rf-CjH8)RuCl2]2 and [Cp RhCl2]2 with silver carboxylates and subsequent hydrogenation afforded mixed metal... 

Very few examples of solid state metathesis reactions are known. In 1932 Hilpert and Wille (7) reported the preparation of mixed metal ferrites at moderate temperatures (400 - 500°C) by the reaction ... 

K [14881-07-3], Rb [72151 -96-3], and Cs [72138-72-8]), are prepared by reaction of elemental fluorine, chlorine trifluoride, or xenon difluoride and a mixture of nickel fluoride and alkaH metal fluorides or other metal haHdes (16,17). If the fluorination is carried out using mixed fluorides, a lower temperature can be used, yields are quantitative, and the final products are of high purity. Bis(tetrafluoroammonium) hexafluoronickelate [6310540-8], (NE 2N iF6> prepared from Cs2NiF3 and NE SbE by a metathesis in anhydrous HE, is also known (18). 

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