Silsesquioxane-Based Amphiphiles

A novel type of amphiphilic spherosilsesquioxane derivative, 1-(1,ω-propylenemethoxy)oligo(ethylene oxide)-3,5,7,9,11,13,15-heptahydridopentacyclo[9.5.1^3,9.1^5,15.1^7,13]octasiloxane has been prepared from (HSiO<INF>3/2</INF>)<INF>8</INF> and allyl-functional oligo(ethyleneoxide) (M<INF>n</INF> = 750 g/mol) by hydrosilylation. The monosubstituted octahydridosilsesquioxane was characterized by ¹H, ¹³C, and ²⁹Si NMR spectroscopy, IR, and MALDI-TOF mass spectroscopy as well as elemental analysis. Surface tension measurements of the water-soluble amphiphile show a cmc in the range of 6 × 10^-4 mol/L. Aggregation of the uncondensed amphiphile leads to micellar and vesicular structures that can be cross-linked to liposome-like silica particles at elevated pH.