SYNTHESIS AND CHARACTERIZATION OF A CHLOROFUNCTIONALIZED UNSATURATED CARBOSILANE OLIGOMER

Acyclic diene metathesis (ADMET) polymerization offers a viable route for the synthesis of chlorofunctionalized unsaturated carbosilane olig omers. The Si-Cl bond in unsaturated carbosilane monomers remains iner t during metathesis and the use of a highly reactive molybdenum-based, Lewis acid-free alkylidene catalyst affords unsaturated chlorofunctio nalized carbosilane oligomers with known vinyl end groups. The first s ynthesis of an unsaturated carbosilane oligomer functionalized with a Si-Cl bond was performed. A chlorofunctionalized silacyclopentene prod uct was also observed, due to a backbiting reaction. This new class of functionalized oligomers has a low glass transition temperature and s ites of unsaturation which may be used for further reaction. ADMET che mistry now provides access to a variety of chlorofunctionalized unsatu rated carbosilanes which can be used to tailor make hydrolytically sta ble carbosilane oligomers and polymers via nucleophilic grafting react ions.