Controlled Thiol-Ene Functionalization of Polyferrocenylsilane-block-Polyvinylsiloxane Copolymers

A general route for the controlled functionalization of polyferrocenylsilane-block-polyvinylsiloxane copolymers, which should be transferable to other silicone-based materials, is developed utilizing the photoinitiated thiol-ene reaction. Poly(ferrocenyldimethylsilane) ₅₄-block-poly(methylvinylsiloxane)₅₁₀ (PFDMS ₅₄-b-PMVS₅₁₀) is synthesized via sequential living anionic polymerization and quantitatively functionalized with a range of thiols, with the aim of tuning the solubility of the resulting materials for self-assembly studies or incorporating more complex functionality for subsequent applications. When functionalization is attempted using a deficit of thiol, the photoinitiator 2,2-dimethoxy-2-phenylacetophenone, used to accelerate the radical reaction, is found to cause significant cross-linking of the polysiloxane chain. Reproducible percentage thiol-ene functionalization of the polysiloxane block can be achieved by the use of PFDMS₅₃-b-PMVS ₅₈/PDMS₄₄₄ (PDMS = polydimethylsiloxane), prepared by the copolymerization of cyclic siloxane monomers, [Me(CHi CH₂)SiO] ₃ and [Me₂SiO]₃, to tune the vinyl group incorporation pre-functionalization. Functional block copolymers: a general route for the controlled functionalization of polyferrocenylsilane-block- polyvinylsiloxane (PFDMS-b-PMVS) copolymers is achieved utilizing the photoinitiated thiol-ene reaction. This method is developed with the aim of tuning the solubility of the resulting materials for self-assembly studies or incorporating more complex functionality for subsequent applications. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.