Electrochemically controlled redox-switchable polymerization uses an electric potential
to bias the monomer selectivity of a catalyst. Many ferrocene-appended catalysts can
exist in two oxidation states, a neutral reduced state and an oxidized cationic state.
Electrochemical generation of the oxidized cationic state produces a charged species
whose counteranion is determined by the identity of the supporting electrolyte anion.
Herein, the role the counteranion has on monomer selectivity and polymerization kinetics
is investigated. Minimal differences in monomer selectivity in the reduced state was
found, however, in the oxidized state, the coordinating ability of the counteranion
greatly influenced the rate of polymerization. How activity differences governed by
the choice of electrolyte can be utilized to access desired diblock copolymers is
also described.
Key words
redox-switchable catalysis - electrochemistry - ring-opening polymerization - organometallic
chemistry
