A one-step method for the synthesis of a vinyl-containing silsesquioxane and other organolithic macromolecular precursors
- Argonne National Lab., IL (United States)
Octasilsesquioxanes are well-known molecules that are presently being used as molecular building blocks in the synthesis of ceramic materials. These materials are synthesized by a variety of means, including mixing several different solution species, photochlorination of [Si{sub 8}O{sub 12}]H{sub 8} followed by treatment with neat methyl cyanide, use of acetic acid and trimethoxy-silane saturated with anhydrous HCl, and employment of excess reactants and long time scales (1-3 years). These methods were inconvenient because they were multistep procedures that used high quantities of starting materials and long reaction times, and delivered low yields of the desired products. Recently, Moran et al. reported a simple method for the synthesis of octakis(dimethylsiloxyl)octasilsesquioxane, [Si{sub 8}O{sub 12}](OSi(CH{sub 3}){sub 2}H){sub 8}. Their method involves the treatment of tetramethylammonium silicate with chlorodimethylsesquioxane in a mixed organic solvent. A one-step synthesis for the introduction of a vinyl functional group onto an octasilsesquioxane molecule has now been developed using the method of Moran. The target molecule, Octakis(vinyldimethylsiloxyl)octasilsesquioxane, [Si{sub 8}O{sub 12}](OSi-(CH{sub 3}){sub 2}(CHCH{sub 2})){sub 8}, is synthesized in high yields using tetramethylammonium silicate and chlorodimethylvinylsilane. The target molecule and several new derivatives have been synthesized and characterized by high-resolution {sup 1}H, {sup 13}C, and {sup 29}Si NMR and by IR. This method is more practical than previous synthesis schemes for the preparation of the vinyl derivative. This new synthesis route allows for the rapid formation of an air-stable silsesquioxane molecule that is easily derivatized to form new organolithic macromolecular materials (OMM`s).
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 255634
- Journal Information:
- Inorganic Chemistry, Vol. 35, Issue 1; Other Information: PBD: 3 Jan 1996
- Country of Publication:
- United States
- Language:
- English
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