The functionalization of octaphenylsilsesquioxane.

摘要

Reported over forty years ago as "unreactive" and "insoluble", the chemistry of octaphenylsilsesquioxane (OPS) has remained unexplored for decades. Consisting of a 0.53 nm diameter silica core and a 1.2 nm diameter organic shell, OPS exhibits both robust chemical and thermal stability as well as a rigid, well-defined structure that make it a desirable precursor to hybrid inorganic-organic composite materials. OPS can be readily synthesized in high yield (90%) from industrially-available phenyltrichlorosilane.; Our initial efforts focused on the direct functionalization and reactivity of OPS by the unreported electrophilic substitution reactions---halogenation and Friedel-Crafts. Methods were developed to measure both the extent of functionalization and the ratios of ortho-meta-para isomers. Further studies focused on the development of more complex hybrid materials from the functionalized OPS molecules. Friedel-Crafts chemistry was used to develop a number of "hairy", alkyl-functional OPS molecules with potential applications as high-temperature lubricants. The Heck and Suzuki chemistry of bromine-functionalized OPS were studied in order to develop hybrid photoluminescent compounds for organic light-emitting diodes.