Octa octasilsesquioxan

X-ray data are available only for the readily accessible octasilsesquioxanes and deca(methylsilsesquioxane) (Table 6). The crystal lattices of octa(alkylsilsesqui-... 

Fig. 24 Octa(dimethylsiloxy)octasilsesquioxane cage-like dendrimers...

Summary Starting with octa(vinyldimethylsiloxy)octasilsesquioxane (QsMs ) as the central core molecule, allyl- and chloro-substituted dendritic macromolecules have been prepared by the divergent route. The sequence of hydrosilylation with dichloro-methylsilane followed by allylation of all Si-Cl groups with CH2=CHCH2MgBr, was used for building up each generation (G1-G4). We also functionalized the dendrimer periphery via hydrosilylation reaction of allyl-functionalized dendrimers with dimethylsilylferrocene. These novel molecules have been characterized by H/ C/ Si-NMR, IR spectroscopy and MALDl-TOF spectrometry. The ferrocenyl-substituted molecules have also been analyzed by cyclovoltammetry. 

In our strategy for the synthesis of carbosilane dendrimers, hydrosilylation and allylation reaction sequences were chosen starting with octa(vinyldimethylsiloxy)octasilsesquioxane (Q lVIg ) as core molecule (Scheme 1). 

As a first step in realizing dendrimers with terminal allyl and chloro groups we prepared the first-generation octa[2-(dichloromethylsilylethyl)dimethylsiloxy]octasilsesquioxane (Gl-CI) via Pt-catalyzed hydrosilylation of the core molecule with dichloromethylsilane. Then each... 

Polyhedral silsesquioxanes present themselves as models for surface-modified silica gels [1]. With the exception of some special cases octasilsesquioxanes normally are obtained by hydrolysis of trichlorosilanes or trialkoxysilanes. Cage rearrangement of octasilsesquioxanes is a new method to prepare mixtures of octa-, deca- and D2d-dodecasilsesquioxanes [2, 3]. These mixtures have to be separated to analyze the single compounds. A new possibility for analyzing silsesquioxanes or silsesquioxane mixtures is given by MALDI-TOF-MS. 

Mixtures of octa-, deca-, and D2d-dodecasilsesquioxanes are obtained by cage rearrangements of octasilsesquioxanes (Eq. 6) [3]. 

P0SS-NH3 Octa(3-ammoniumpropyl) octasilsesquioxane octachlo ride... 

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