Abstract: A synthetic process for the selective preparation of reactive polyhedral oligomeric silsesquioxanes (POSS) as well as polyhedral oligomeric silicate (POS) (spherosilicate) is provided. The method claimed herein employs metal catalyzed metathesis reactions for the selective reaction of .alpha.-olefin containing polyhedral oligomeric silsesquioxanes or silicates with olefinic reagents bearing functionalities useful for grafting reactions, polymerization chemistry and sol-gel processes. The use of metal catalyzed metathesis chemistry to form both linear or network polyhedral silsesquioxane polymers directly from .alpha.-olefin-containing polyhedral oligomeric silsesquioxanes is also described.