Hydrolysis of organometallic compounds

Hydrolysis of Organometallic Compounds Hydro-de-metallation or Demetallation... 

Fukushima, f. (1976) Preparation of BaTiOs films by hydrolysis of organometallic compounds. Am. Ceram. Soc. Bull., 55 (12), 1064. 

This technique produces ceramic materials from a solution. The starting particles are smaller (a few nanometers) than for traditional techniques since the particles are obtained by hydrolysis of organometallic compounds or metallic salts to oxides. The ceramic materials so obtained are more dense with a higher resistance to compression. As a result, imperfections are smaller and less frequent than with other methods. A few cracks of less than 1 pm are formed, while traditional materials can have pinholes of up to 1 mm. 

Formation constants for complex species of mono-, di-, and trialkytin(rV) cations with some nucleotide-5 -monophosphates (AMP, LIMP, IMP, and GMP) are reported by De Stefano et al. The investigation was performed in the light of speciation of organometallic compounds in natural fluids (I = 0.16-1 moldm ). As expected, owing to the strong tendency of organotin(IV) cations to hydrolysis (as already was pointed above) in aqueous solution, the main species formed in the pH-range of interest of natural fluids are the hydrolytic ones. ... 

Membranes with extremely small pores ( < 2.5 nm diameter) can be made by pyrolysis of polymeric precursors or by modification methods listed above. Molecular sieve carbon or silica membranes with pore diameters of 1 nm have been made by controlled pyrolysis of certain thermoset polymers (e.g. Koresh, Jacob and Soffer 1983) or silicone rubbers (Lee and Khang 1986), respectively. There is, however, very little information in the published literature. Molecular sieve dimensions can also be obtained by modifying the pore system of an already formed membrane structure. It has been claimed that zeolitic membranes can be prepared by reaction of alumina membranes with silica and alkali followed by hydrothermal treatment (Suzuki 1987). Very small pores are also obtained by hydrolysis of organometallic silicium compounds in alumina membranes followed by heat treatment (Uhlhom, Keizer and Burggraaf 1989). Finally, oxides or metals can be precipitated or adsorbed from solutions or by gas phase deposition within the pores of an already formed membrane to modify the chemical nature of the membrane or to decrease the effective pore size. In the last case a high concentration of the precipitated material in the pore system is necessary. The above-mentioned methods have been reported very recently (1987-1989) and the results are not yet substantiated very well. 

The reaction normally does not stop at this stage MgXZ is eliminated and the resulting ketone rapidly reacts with another molecule of organometallic compound. On hydrolysis, a tertiary alcohol is formed with at least two identical alkyl groups on the tertiary carbon ... 

The Grignard reaction is often one of the first reactions encountered for the preparation of organometallic compounds. As such it provides a method for the conversion of an alkyl bromide to an alkane. From the example shown below it is seen that the overall oxidation level change from the organic reactants to the products is from 0 to —2, so a reduction has occurred. Magnesium is the reductant and is itself oxidized from 0 to +2 oxidation state. The actual reduction takes place in the first step of the process in which the C-Br bond is converted to a C-Mg-Br bond. The reaction with water is merely a hydrolysis that does not change the oxidation state of carbon. 

Also proposed was a method of determining diisobutylisobutoxyaluminium and isobutyldiisobutoxyaluminium in triisobutylaluminium from the hydrolysis product, namely isobutyl alcohol [101]. Many other examples of the analysis of organometallic compounds from the products of their hydrolysis can be found in an excellent review by Ivanova and Frangulyan [98]. 

The enamine 193 as a carbon nucleophile reacts with TT-allylpalladium chloride to give 2-allylcyclohexanone after hydrolysis [84]. Hard carbon nucleophiles of organometallic compounds also react with TT-allylpalladium complexes. A steroidal side chain was introduced to 194 to afford 197 regio- and stereoselectively by the... 

The chemical reactivity of organometallic compounds, in particular those of the elements of Groups I, II, and III, renders them well-suited to study by reaction calorimetric methods. Examples reported include measurements of the heats of hydrolysis of alkyls of Li, Zn, Cd, and Al, the heats of hydroboration of olefins, and the heats of halogenation of alkyls of Zn, Cd, Hg, Sn, and Ga. The heat of formation data derived by use of these methods are discussed in the following Section, in which best AHf° values are selected from the available published data on compounds containing metal-carbon bonds. 

Salts, oxides, organometallic derivatives of divalent and triva-lent metals are the most usual stereospecific initiators used both for oxiranes and thiiranes. Many of them were already described in reviews (1-6). The most studied of them result from modification reactions of organometallic compounds such as ZnEt the hydrolysis of which was described by Furukawa, Tsuruta (1959 and Colclough (1964), the alcoolysis mainly studied by Tsuruta... 

Phenyllithium slowly cleaves decaphenylcyclopentasilane in tetrahydro-furan-ether to give, with an excess of organometallic compound and extended reaction times, pentaphenyldisilane (45) as the major product after acid hydrolysis. Decaphenylcyclopentasilane reacts with a 5 mole excess of methyllithium to give l-lithio-2-methyltetraphenyldisilane, characterized as 1,2-dimethyltetraphenyldisilane (23). ... 

Organometallic compounds can be hydrolyzed by acid treatment. For active metals such as Mg, Li, and so on, water is sufficiently acidic. The most important example of this reaction is hydrolysis of Grignard reagents, but M may be many other metals or metalloids. Examples are SiRs, HgR, Na, and B(OH)2- Since aryl Grignard and aryllithium compounds are fairly easy to prepare, they are often used to prepare salts of weak acids, for example,... 

The coordination of the alkyne to the rhodium catalyst allows the carborhodation of the triple bond to afford the vinylrhodium intermediate 47 (Scheme 14). The rearrangement of this organometallic compound into the 2-(alkenyl)phenylrhodium intermediate 48 is evidenced by one deuterium incorporation resulting from the deuter-iolysis of the Rh-C bond. The addition of the phenylrhodium intermediate 45 must occur before its hydrolysis with water. The 2-(alkenyl)phenylrhodium intermediate 45, generated by the phenylrhodation of an alkyne followed by... 

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