Organometallic-polypeptide block copolymers: synthesis and self-assembly of poly(ferrocenyldimethylsilane)-b-poly(epsilon-benzyloxycarbonyl-L-lysine).

A new type of metallopolymer-polypeptide block copolymer poly(ferrocenyldimethylsilane)-b-poly (epsilon-benzyloxycarbonyl-L-lysine) was synthesized by ring-opening polymerization of epsilon-benzyloxycarbonyl-L-lysine N-carboxyanhydride initiated by using a primary amino-terminated poly(ferrocenyldimethylsilane). Studies on the self-organization behavior of this polypeptide block copolymer in both the bulk state and in solution were performed. In the bulk state, a cylindrical-in-lamellar structure was observed in a compositionally asymmetric sample. Rod-like micelles with a polyferrocenylsilane core formed in a polypeptide-selective solvent alone or in the presence of a common solvent. Significantly, an additional small quantity of the common solvent assisted the formation of longer micelles and micelles with better shape-regularity. This is attributed to a decrease in the number of nucleation events and PFS core reorganization effects.