Monosilylated silsesquioxane precursor

The fulvene route was also successfully employed in the preparation of a compound, which can be regarded as one of the most advanced molecular models for a catalytically active titanium center on a silica surface. When Cp Ti(C5Me4CH2) was reacted with the monosilylated silsesquioxane precursor 12 in refluxing toluene a color change from deep purple to amber was observed. Crystallization afforded a bright-yellow material, which was subsequently shown to be the novel mo o(pentamethyleyclopentadienyl) titanium(IV) silsesquioxane complex 126 (69% yield). Its formation is illustrated schematically in Scheme 42. 

The first silsesquioxane derivative of copper was made in our laboratory according to Scheme 65. The reaction of the monosilylated disilanol precursor 12 with tetrameric copper(I)-r-butoxide in a molar ratio of 2 1 afforded the colorless copper(I) silsesquioxane complex 187, in which the CU4O4 core of copper(I)-t-but-oxide is retained. 

A series of ferrasilsesquioxanes stabilized by phosphine ligands has been prepared and characterized by Baker et al Reactions of the iron(II) precursor FeCl2(dcpe) (dcpe = bis(dicyclohexylphosphino)ethane) with 2 or the monosilylated precursor (c-C5H9)7Si70g(0SiMe3)(0FI)2 (38) afforded the (dcpe)iron(II)-silsesquioxane... 

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