Enlarging the Toolbox: Epoxide Termination of Polyferrocenylsilane
(PFS) as a Key Step for the Synthesis of Amphiphilic PFS–Polyether
Block Copolymers
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Abstract
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<sup>–1</sup> 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-<i>b</i>-ethylene oxide) block copolymers with a low polydispersity
index. All polymers have been characterized by <sup>1</sup>H NMR spectroscopy,
DOSY <sup>1</sup>H NMR spectroscopy, size exclusion chromatography
(SEC), and MALDI-ToF mass spectrometry. In addition, for the characterization
of the morphology of the PFDMS-<i>b</i>-PEO block copolymers
transmission electron microscopy (TEM) was performed in methanol,
confirming the formation of cylindrical micelles with an organometallic
core and polyether corona