Enlarging the toolbox: Epoxide termination of polyferrocenylsilane (PFS) as a key step for the synthesis of amphiphilic PFS-polyether block copolymers

Epoxide termination and functionalization of living poly(ferrocenyldimethylsilane) (PFDMS) is introduced by precapping the living PFDMS with a 4/2 molar mixture of 1,1-diphenylethylene and 1,1- dimethylsilacyclobutane acting as a "carbanion pump" system. Subsequent addition of allyl glycidyl ether (AGE) leads to quantitatively functionalized PFDMS-AGE polymers with molecular weights between 1500 and 15 400 g mol^-1 and polydispersity indices ≤1.10, carrying one hydroxyl group and an additional allylic double bond. PFDMS-AGE was then applied as a macroinitiator for the living anionic ring-opening polymerization of ethylene oxide (EO) to generate amphiphilic and water-soluble poly(ferrocenyldimethylsilane-b-ethylene oxide) block copolymers with a low polydispersity index. All polymers have been characterized by ¹H NMR spectroscopy, DOSY ¹H NMR spectroscopy, size exclusion chromatography (SEC), and MALDI-ToF mass spectrometry. In addition, for the characterization of the morphology of the PFDMS-b-PEO block copolymers transmission electron microscopy (TEM) was performed in methanol, confirming the formation of cylindrical micelles with an organometallic core and polyether corona.