An Efficient Approach to Octabromophenylethyl-Functionalized Cage Silsesquioxane and Its Use in Constructing Hybrid Porous Materials: Octabromophenylethyl-Functionalized Cage Silsesquioxane

Octabromophenylethyl-functionalized silsesquioxane (BrPh-SQ) was synthesized by the Friedel–Crafts alkylation of octavinylsilsesquioxane (OVS) with bromobenzene, which acted as both the solvent and reactant and, furthermore, could be recycled after the reaction. The approach possesses the advantages of being mild, economic, and highly efficient. Further, BrPh-SQ was used as a building block in Heck reactions with OVS and tetrakis(4-vinylphenyl)silane to form two hybrid network polymers, that is, cage polymers 1 and 2, respectively. Cage polymer 1 showed moderate porosity with a Brunauer–Emmett–Teller specific surface area of 334 m2 g–1 and a total pore volume of 0.208 cm3 g–1. For gas-sorption applications, the CO2 uptake of cage polymer 1 was 2.44 wt.-% (0.55 mmol g–1) at 273 K and 101 kPa.