SYNTHESIS OF HIGHLY FUNCTIONALIZED DENDRIMERS BASED ON POLYHEDRAL SILSESQUIOXANE CORES

A number of dendrimers based on polyhedral silsesquioxane cores have b een synthesised and characterised. The new molecules are prepared by r epetitive hydrosilation/alkenylation reactions, which provide a facile and high yield route to dendrimers with a high density of branch ends per generation. Judicious choice of hydrosilating agent [HSiCl3, H(CH 3)SiCl2 or H(CH3)(2)SiCl] produces dendrimers with varying numbers of chain ends, and alkenylating agents of different lengths produce molec ules with different physical properties. The 24-vinyl functionalised d endrimer, 5, has been characterised using single-crystal X-ray diffrac tion techniques.