Unprecedented Formation of <i>cis</i>‐ and <i>trans</i>‐Di[(3‐chloropropyl)isopropoxysilyl]‐Bridged Double‐Decker Octaphenylsilsesquioxanes

Abstract

Abstract Silsesquioxane formation competing with the deprotonation of alcohol solvents in the presence of a strong base to form alkoxides is reported for the first time. Evidently, sodium isopropoxide is formed during the synthesis of the sodium salt of a double‐decker octaphenylsilsesquioxane tetrasilanolate in 2‐propanol as the solvent, which leads to the formation of unexpected cis ‐ and trans ‐di[(3‐chloropropyl)isopropoxysilyl]‐bridged double‐decker octaphenylsilsesquioxanes after in situ coupling with 3‐chloropropyltrichlorosilane. The desired products were characterized by 1 H NMR, 13 C NMR, and 29 Si NMR spectroscopy; ESI‐MS; and single‐crystal X‐ray diffraction.