Vinyl ferrocenyl glycidyl ether: an unprotected orthogonal ferrocene monomer for anionic and radical polymerization

• Published in: Polymer chemistry 2015-01, Vol.6 (19), p.3617-3624
• Main Authors: Alkan, Arda, Thomi, Laura, Gleede, Tassilo, Wurm, Frederik R.
• Format: Article
• Language: English
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/C5PY00404G

The first orthogonal ferrocene monomer, vinyl ferrocenyl glycidyl ether (VfcGE), for both anionic and radical polymerization – without the need of a protection group – is presented. Anionic ring-opening copolymerization of VfcGE and ethylene oxide (EO) generates stimuli-responsive, multifunctional poly[(vinyl ferrocenyl glycidyl ether)- co -(ethylene oxide)] (P[VfcGE- co -EO]) copolymers (molecular weights of ca. 7500 g mol −1 and low molecular weight dispersities ( Đ ≤ 1.14)). The amount of the equimolar ferrocenyl and vinyl groups are controlled by the comonomer ratio up to 15.4 mol% VfcGE. The pendant vinyl groups of P[VfcGE- co -EO] were post-modified with 3-mercaptopropionic acid via thiol–ene chemistry. The EO copolymers exhibit temperature-, redox-, and pH-responsive behavior in water depending on the polymers’ microstructure. Free radical polymerization of VfcGE leads to polyalkylene:(vinyl ferrocenyl glycidyl ether) with pendant epoxide side chains at each ferrocene unit. The resulting polymer was used to generate redox-responsive protein nanoparticles with bovine serum albumin (BSA) by nucleophilic ring-opening of the pendant epoxides.