The hydrolytic condensation of RSiCl3 (R = benzyl, m-tolyl, 3,5-dimethylphenyl) gives good yields of the corresponding octameric aryl silsesquioxanes (1). A single-crystal X-ray diffraction study of highly soluble 1 (R = benzyl) reveals that highly efficient crystal packing can be accomplished without the inclusion of solvent or the strong intermolecular π-stacking arrangements that normally lead ... [Show full abstract] to poor solubility properties. The catalytic hydrogenation of aryl polyhedral oligosilsesquioxanes (POSS) affords high yields of the corresponding aliphatic silsesquioxanes. These new silsesquioxanes display thermal and physical properties comparable to the corresponding aryl-containing POSS but generally have much greater solubilities in common organic solvents. The catalytic hydrogenation of [Ph12Si12O20] affords iso-[Cy12Si12O20], which possesses local C2v rather than D6h symmetry.