Cage octasilsesquioxane

Z13 Synthesis of Cage Octasilsesquioxane Dehydration of Silanols 434... 

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

Fig 1. General structure of octasilsesquioxane compounds. R stands for H, D, Me, Et, Pr, C-C6H12, C2H3, C6H5, OSiMes, OSi(CD3)3, 3-ehIoropropyl. Cages with mixed substitution patterns as well as heterosilsesquioxanes have been studied successfully [3]. 

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]. 

Bassindale AR, Parker DJ, Poumy M, Taylor PG, Horton PN, Hursthouse MB (2004) Fluoride ion entrapment in octasilsesquioxane cages as models for ion entrapment in zeolites. Further examples. X-ray crystal structure studies, and investigations into how and why they may be formed. Organometallics 23(19) 4400 405. doi 10.1021/0m049928g... 

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