vinyl, allyl), have been synthesized. The structures of the complexesCp2M[(c-C5H9)7Si7O11](OSiMe2CH2CHCH2) (M = Zr (3d), Hf (5d)) have been unambiguously established by single-crystal X-ray diffraction analyses. Silylation or germylation of the zirconocene-containing silsesquioxane monosilanol Cp2Zr[(c-C5H9)7Si7O11](OH) (3a) or its hafnocene derivative Cp2Hf[(c-C5H9)7Si7O11](OH) (5a), which can be prepared
一系列含有茂金属的倍半硅氧烷与alkenylsilyl和三甲基甲硅烷基,CP ' 2 M [(CC 5 ħ 9)7的Si 7 ø 11 ](OSiMe 2 R)(图2b - d,3B - d,4D,5D:CP' = Cp(环戊二烯基),Cp *(五甲基环戊二烯基); M = Ti,Zr,Hf,R =甲基,乙烯基,烯丙基)。配合物Cp 2 M [(cC 5 H 9)7 Si 7 O 11 ](OSiMe 2的结构CH 2 CH CH 2)(M = Zr(3d),Hf(5d))已通过单晶X射线衍射分析明确建立。含锆茂的倍半硅氧烷单硅醇Cp 2 Zr [(cC 5 H 9)7 Si 7 O 11 ](OH)(3a)或其ha衍生物Cp 2 Hf [(cC 5 H 9)7 Si 7 O 11 ](OH)(5a),可以通过倍半硅氧烷倍半硅氧烷三硅醇(cC 5 H 9)7 Si 7 O 9(OH)3(1
Synthesis of Cooligomers of Titanium-Bridged Silsesquioxanes and Octakis(hydridosilsesquioxane)
New titanium-bridged silsesquioxanes having olefinic groups, Ti[(c-C5H9)7Si7O12(SiMe2R)]2 (R = vinyl, allyl), react with octakis(hydridosilsesquioxane) under hydrosilylation reaction conditions to give oligomeric materials. The local structure around the titanium atoms of the starting silsesquioxanes is unchanged even in the oligomeric materials.
Novel zirconocene or hafnocene-containing silsesquioxanes with a vinyl group Cp2M[(vinyl)Me2Si](c-C5H9)7Si7O12} (Cp = cyclopentadienyl, M = Zr, Hf) were synthesized, as well as a derivative with a trimethylsilyl group Cp2Zr[(Me3Si)(c-C5H9)7Si7O12]. A derivative containing a dimethylethoxysilyl group was also synthesized.
Silsesquioxane Models for Geminal Silica Surface Silanol Sites. A Spectroscopic Investigation of Different Types of Silanols
作者:Tessa W. Dijkstra、Robbert Duchateau、Rutger A. van Santen、Auke Meetsma、Glenn P. A. Yap
DOI:10.1021/ja0122243
日期:2002.8.1
and FT-IR studies show that the two silanols of the geminal silsesquioxanes 4-6 are different from each other with respect to hydrogenbonding, both in solution and in the solid state. Hydrogenbonding of the geminal silanol-containing silsesquioxanes was examined and compared to hydrogenbonding in silsesquioxanes possessing vicinal or isolated silanol groups. The relative Brønsted acidity of the geminal