Synthesis, Characterization and Reactivity of cis-cis-cis [ (C₆H₅)₄Si₄O₄(OH)₄]

Article type: Research Article

Authors: Feher, Frank J. | Schwab, Joseph J. | Soulivong, Daravong | Ziller, Joseph W.

Affiliations: Department of Chemistry, University of California, Irvine, California 92697-2025

Note: [] Corresponding author.

Abstract: The hydrolytic condensation of PhSiCl3 (H2O/acetone, 0–5°C, 18 h) precipitates cis-cis-cis-[(C6H5)4Si4O4(OH)4] (5a) as the sole crystalline product in approximately 40% yield. The all-cis structure, which was originally assigned by J. F. Brown on the basis of IR spectroscopy and derivatization studies, was confirmed by a single-crystal X-ray diffraction study. The ether solvate of 5a crystallizes from Et2O/C6H6 as a hydrogen-bonded, dimeric structure, which kinetically stabilizes the molecule toward self-condensation reactions. In solution, particularly in the presence of weak amine bases, 5a rapidly self-condenses to form “T-resins”; self-condensation also occurs in the solid-state (25° C) over several months. Tetrasilanol 5a can be exhaustively silylated with Me3SiCl to afford excellent yields of cis-cis-cis-[(C6H5)4Si4O4(OSiMe3)4], but all attempts to effect clean partial silylation produced complex mixtures of partially silylated T-resins. Attempts to effect catalytic hydrogenation of 5a to cis-cis-cis[(c-C6H11)4Si4O4(OH)4] (16) produced several products, including completely-condensed frameworks [(c-C6H11)8Si8O12] (6b) and [(c-C6H11)6Si6O9] (16).

DOI: 10.1080/10241229712331341254

Journal: Main Group Chemistry, vol. 2, no. 2, pp. 123-132, 1997