Preparation of Novel Organic-Inorganic Hybrid Materials for Catalysts from Metal-Containing Silsesquioxanes

含硅醇基的不完全缩合低聚硅氧烷和含金属硅氧烷从离散的、定义良好的可溶模式化合物的角度引起了广泛的关注。本文从制备有机-无机杂化材料前驱体的角度出发，合成了一系列含硅基或胚芽基官能团的4族茂金属硅氧烷。研究了利用这些含金属的硅氧烷制备多孔氧化物催化剂。(1)含多种金属硅氧烷微孔固体氧化物的制备：在823 K左右对新合成的含13族硅氧烷进行控制煅烧，制备出高BET比表面积（330-520 m^2g^<-1>）的Bronsted酸性氧化物，微孔控制均匀，孔径为5.1Å。它们的酸性性质受硅氧烷前体结构的影响较大，部分受13族元素和反阳离子的选择控制。特别是，铝桥接硅氧烷的氧化物具有较高的BET表面积和大量的酸性位点。13族元素氧化物在硅基中的分散差异被认为是导致其酸性特性差异的原因之一，这与前驱体的结构密切相关。根据对典型碳氢化合物（如异丙烯）裂解的初步研究，这些氧化物尽管具有非晶态性质，但却表现出异常高的活性。(2)新型含官能团的第4族过渡金属硅氧烷的合成：探索了一系列含烯基硅基和三甲基硅基的含茂金属硅氧烷的制备方法。其中，配合物Cp_2M[(c-C_5H_9)_7Si_7O_<11>](OSiMe_2CH_2CH=CH_2) [M = Zr或Hf]的结构通过单晶x射线衍射分析得到了明确的确定。初步考察了这些含茂金属的硅氧烷对过氧化叔丁基环氧化环己烯的催化活性，结果表明，含钛二茂金属的硅氧烷具有中等的催化活性。少

Incompletely condensed oligosilsesquioxanes with silanol groups and metal-containing silsesquioxanes have attracted much attention from the viewpoint of discrete, well-defined soluble model compounds of the transition metal-containing siliceous heterogeneous catalysts. In the present work, synthesis synthesis of a series of group 4 metallocene-containing silsesquioxanes with functional silyl or germyl groups have been performed from the viewpoint of the preparation of precursors of organic-inorganic hybrid materials for catalysts. Preparation of porous oxide catalysts utilizing these metal-containing silsesquioxanes was also examined.(1)Preparation_of Microporous Solid Oxides from Various-Metal Containing Silsesquioxane:The controlled calcination of newly-synthesized group 13 elements-containing silsesquioxanes at around 823 K produces Bronsted acidic oxides with high BET surface areas of 330-520 m^2g^<-1> and uniformly-controlled micropores of 5.1Å diameter diameter. Their acidic prop … More erties are greatly affected by the structure of silsesquioxane precursors, and partly controlled by the selection of group 13 elements and counter cations. In particular, oxides from aluminum-bridged silsesquioxanes were found to have high BET surface areas and a large amount of acidic sites. Differences in the dispersion of oxides of group 13 elements in silica matrixes, which are closely related to the structure of precursors, are considered to be one of the reasons of differences in their acidic characters. According to the preliminary study on the cracking of model hydrocarbons such as cumene, these oxides show exceptionally high activity in spite of their **orphous nature.(2)Synthesis of Novel Group 4 Transition Metal-Containing Silsesquioxanes with Functional Groups:Several preparation methods of a series of metallocene-containing silsesquioxanes with alkenylsilyl and trimethylsilyl groups have been explored. Among them, the structures of the complexes Cp_2M[(c-C_5H_9)_7Si_7O_<11>](OSiMe_2CH_2CH=CH_2) [M = Zr or Hf] are unambiguously established by the single-crystal X-ray diffraction analysis. The preliminary examination of the catalytic activity of these metallocene-containing silsesquioxanes towards the epoxidation of cyclohexene by tert-butyl hydroperoxide revealed that titanocene-containing silsesquioxanes show modest catalytic activity. Less