Organosilicon compounds, preparation stability

Platinum-sllylenes are important to numerous transformations involving organosilicon compounds. Base-stabilized Fisher-type cationic silylene complex of platinum(II) may be prepared by anion abstraction from a silyl group, as shown in Scheme 51. The counter anion is crucial... 

Since 1989, when the first volume of The Chemistry of Organosilicon Compounds appeared1, large strides have been made in preparing silicenium cations. The first X-ray structures2,3 of solvent stabilized silicenium cations are among the most notable successes. Most recently, a free silicenium cation has been prepared in solution4 5. In addition... 

Summary 2-(Trimethylhydrazino)phenyl substituted organosilicon compounds 3, 4, and 5 were prepared. Their NMR spectra reflect the pentacoordination of the silicon center in solution at room temperature. Compound 5 is hexacoordinated in the solid state, whereas 4 shows pentacoordination. The phenyltrimethylhydrazino as well as the dimethylbenzylamino substituent proved to be highly suitable for the intramolecular stabilization of silyl cations. 

Silicon compounds with coordination number larger than four are the object of many studies first with respect to their application as catalysts in organic and inorganic syntheses and second as starting materials for the preparation of a broad variety of organosilicon compounds [1]. Additionally, hypervalent silicon hydride compounds can successfully be used as model compounds to study, for instance, the mechanism of nucleophilic substitution reactions, which is of great interest since the silicon atom is able to easily extend its coordination number [1]. Moreover, hypervalent silanes are suitable as starting materials for the synthesis and stabilization of low-valent silanediyl transition metal complexes [2-5]. 

The initial work on plasma polymerization of organosilicon compounds was done by Tkachuk et al.(6-8) who prepared siloxane and organosiloxane films under different processing conditions, and studied rates of deposition. The films were characterized by IR and ESR. Some of the more recent publications show that the plasma polymerization of organosilicon monomers yields films exhibiting excellent properties, such as high thermal stability ) and high dielectric constant.(10,11) Such films have found use as dielectrics for microelectronics, and in optical(12, 13) and biomedical applications.(14)... 

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