Synthesis and structural characterization of two complex tantalum(V) siloxides

Abstract

The reaction of tantalum(V) ethoxide, Ta(OEt)5, with 1 equiv. of 1,1,3,3-tetraphenyl-disiloxane-1,3-diol, (HO)SiPh2OSi-Ph2(OH) (1), afforded the dinuclear tantalum(V) disiloxanediolate complex [{μ-(Ph2OSiO)2O}Ta(OEt)2(μ-OEt)]2 (3). Similarly, Ta(OEt)5 reacted with the incompletely condensed silsesquioxane precursor Cy7Si7O9(OH)3 (2, Cy=cyclohexyl) in a 1:1molar ratio to afford the dinuclear tantalasilsesquioxane derivative [Cy7Si7O12Ta(OEt)(μ-OEt)]2 (4) in 80% yield. Both new complexes were structurally characterized by single-crystal X-ray diffraction studies.