Silicon-oxygen complexes configuration

All these reasons have prompted us to perform nonempirical quantum-chemical calculations that could clarify the problem. Zelenkovskii (16) carried out such computations of adsorption complexes with HzO and NH3 molecules. Figure 9 shows two types of adsorption of water, where adsorption is considered either (a) on the face or (b) on the edge of a silicon-oxygen tetrahedron. The calculations involved a series of adsorption complexes with different distances R between the oxygen atom of water and a silicon atom and with various values of angle a. describing the deviation from the tetrahedral configuration. STO-3G, STO-3G, and 3-21G basis sets were used in these computations. 

As already briefly mentioned, the oxygen-atom insertion into Si—H bonds of silanes constitutes a selective method for the chemoselective preparation of silanols, which has been much less studied compared to the CH oxidation. This unique oxyfunctionalization of silanes is also highly stereoselective (equation 35) since, like the CH insertions, it proceeds with complete retention of configuration. A novel application of the SiH insertion process is the synthesis of the unusual iron complex with a silanediol functionality, in which selectively both Si—H bonds of the silicon atom proximate to the iron ligand are oxidized in the silane substrate (equation 36). ... 

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