Heterosilsesquioxanes: Synthesis and characterization of group 15 containing polyhedral oligosilsesquioxanes

Article abstract of DOI:10.1021/om00049a051

The reactions of [(c-C₆H₁₁)7Si₇O₉(OH)₃] (1) with PCl₃, AsCl₃, and SbCl₃ give high yields of the corresponding pnictite esters, [(c-C₆H₁₁)₇Si₇O₁₂M], M = P (2), As (3), Sb (4). The bismuth congener, [(c-C₆H₁₁)₇Si₇O₁₂Bi] (5), was prepared by the reaction of 1 with (t-BuO)₃Bi. A single-crystal X-ray diffraction study of 2 reveals an interesting molecular structure with 1 of the 12 framework oxygen atoms lying inside the cube defined by the Si and P atoms. Phosphite 2 forms a 1:1 adduct with Me₃Al and is quantitatively oxidized to phosphate [(c-C₆H₁₁)₇Si₇O₁₂PO] (7) by ozone.