Magnesium mixed

More recent investigations have shown that the reaction of a Na(tmp)/Bu Mg(tmp)/ tmeda mixture with 0.5 equivalent of benzene leads to dideprotonation of the arene to afford [ (tmeda)Na(p-tmp)Mg(tmp)2 2C6H4]. 5 The reaction of the magnesium amide Mg(tmp)2 with LiN(SiMe5)2 resulted in a deprotonation/amine elimination process as shown in Scheme 3.7. The product, a dimeric lithium/magnesium mixed amide has a conformationaUy locked structure with two stereogenic nitrogen centres. ... 

Figure 31 The structure of the lithium-magnesium, mixed amide (if,if/5,5)- LiMg(TMP)[CH2Si(Me)2N-...

Johnson has studied the cerium modification of the Peterson methylenation. (Trimethylsilyl)methyl-lithium was added to CeCh and the addition carried out in the presence of TMEDA (equation 8). The cerium lithium reagent proved to be superior to the lithium, magnesium or cerium magnesium mixed... 

Synthesis and acid-base properties of catalysts based on magnesium and sodium-magnesium mixed phosphates... 

Various solids consisting of magnesium and sodium-magnesium mixed orthophosphates were synthesized and used as catalysts in the transformation of 2-hexanol. The solids obtained were characterized by using various elucidation techniques. In particular, acid-base properties were determined by several methods. The solids were found to be active in the dehydration and dehydrogenation of the alcohol studied, and to be highly selective towards the dehydrogenation product in some instances. In addition to surface properties, the structure and composition of the catalysts -particularly their sodium content- appear to play essential roles in their catalytic behaviour. 

The composition of the solids (Table 2) is consistent with their structures. The most salient outcome is probably the presence of sodium due to the formation of sodium-magnesium mixed orthophosphates. Chlorine was also present as NaCI in solid NaMgP-2. 

Catalysts MgPc and MgP possess an Mg3(P04)2 structure and hence Brdnsted sites of the P-O-H type [22], which are responsible for the dehydrating activity. On the other hand, the basicity of sodium-magnesium mixed phosphates has been ascribed to the basic character of the... 

The different catalytic behaviour between solids MgPc and MgP can be ascribed to the presence of a small amount of sodium in the latter (Table 2). This could indicate the existence of some residual sodium-magnesium mixed orthophosphates dispersed on the surface of Mg3(P04)2. It would contribute to its higher basicity and therefore to its dehydrogenating ability, which is absent on solid MgPc. This would also explain the increased total conversion for solid MgPc. On the other hand, this solid exhibits a higher density of acid sites (6.3 pmol m ) as compared to solid MgP (2.9 pmol m ) and, in addition, the influence of the structure of the surface sites cannot be discarded. 

Aramendia. MA Borau. V Jimenez, C Marinas, JM Roldan. R Romero, FJ Urbano. FJ. Synthesis and acid-base properties of catalysts based on magnesium and sodium-magnesium mixed phosphates. Studies in Surface Science and Catalysis, 2002 143, S99-906. 

In a somewhat different manner, the hydrolytic and heat-forming influence of water prevails in some fuel-oxidizer systems that are reactive in the common manner of pyrotechnical combinations, but will also be brought to an intensely-hot flaming reaction by the addition of small amounts of water. Most of these combinations contain sodium peroxide as the oxidizer. Aluminum and magnesium, mixed with sodium peroxide, have been recommended as igniters for the thermite mixtures described later. The magnesium/sodlum peroxide can even be initiated by carbon dioxide. The high reactivity of these combi-... 

Using Lithium- or Sodium-Magnesium Mixed-Metal Bases... 

The reductive pyrolysis of organic compounds in the presence of metals leads to the formation of the metal cyanide, which can be detected as Prussian blue (Fe4[Fe(CN)g]3) or by the copper(ii) acetate-benzidine test . Several metals and salts have been recommended for the fusion of the organic compound, e.g. potassium , sodium , magnesium mixed with potassium carbonate , zinc mixed with potassium carbonate , and a mixture of dextrose with sodium carbonate . When the compound contains sulphur the metal thiocyanate is also produced, which can be detected by ferric chloride . ... 

Andrikopoulos PC, Armstrong DR, Kennedy AR, et al. Synthesis and structural characterisation of mixed alkali metal-magnesium mixed Hgand alkyl-amido ate complexes. Inorg Chim Acta. 2007 360(4) 1370-1375. 

Garcia-AlvarezJ, Graham DV, Hevia E, Kennedy AR, Mulvey RE. Synthesis and characterisation of new bimetallic alkali metal-magnesium mixed diisopropylamide-acetyhdes structural variations in bimetallic lithium- and sodium-heteroleptic magnesiates. Dalton Trans. 2008 (11) 1481—1486. 

Solsona, B., Dejoz, A., Vazquez, M., et al (2001). Si02-Supported Vanadium Magnesium Mixed Oxides as Selective Catalysts for the Oxydehydrogenation of Short Chain Alkanes, Appl. Catal. A Gen., 208, pp. 99-110. 

Bartek, J.P., Hupp, J.M., Brazdil, J.F., and Grasselli, R.K. (1988) Oxidative Dimerization of Methane Over Lead-Magnesium Mixed Oxide Catalysts , Catalysis Today 3,117-26. 

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