The functionalization of octaphenylsilsesquioxane.

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.Ph.D.Polymer chemistryPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/125035/2/3186588.pd