The supramolecular redox functions of metallomacromolecules

Abstract

Metallomacromolecules are frequently encountered in redox proteins including metal-tanned hide collagen and play crucial roles involving supramolecular properties in biological electron-transfer processes. They are also currently found in non-natural families, such as: metallopolymers, metallodendrimers and metallodendronic polymers. This mini-review discusses the supramolecular redox functions of such nanomaterials developed in our research group. Electron-transfer processes are first examined in mono-, bis- and hexa-nuclear ferrocenes and other electron-reservoir organoiron systems showing the influence of supramolecular and reorganization aspects on their mechanism. Then applications of electron-transfer processes using these same organoiron redox systems in metallomacromolecules and their supramolecular functions are discussed including redox recognition/sensing, catalysis templates, electrocatalysis, redox catalysis, molecular machines, electrochromes, drug delivery device and nanobatteries.

Graphical Abstract

Ferrocene-containing amphiphilic polynorbornenes as biocompatible drug carriers

Ferrocene-containing diblock and random polynorbornene-based copolymers were synthesized by ROMP and used as biocompatible drug carrier micelles.

Synthesis of Air-Stable Cyclopentadienyl Fe(CO)2 (Fp) Polymers by a Host-Guest Interaction of Cyclodextrin with Air-Sensitive Fp Pendant Groups

Host-guest chemistry is used to address the challenge of the synthesis of air-stable polymers containing air-sensitive metal complexes. The complexation of the CpFe(CO)₂ (Fp) pendent group with cyclodextrin (CD) molecules created air-stable poly(Fp-methylstyrene) P(CD/FpMSt). This CD complexation resulted in dimerization of the adjacent Fp groups, which was characterized by NMR, FTIR, and cyclic voltammetry (CV) analyses. P(CD/FpMSt) was soluble in DMSO and remained stable even the solution was exposed to air for months. The host-guest chemistry accounted for the improved stability, because the Fp groups decomposed upon removal of the CD molecules using competing guest molecules. The CD-complexed polymer showed light-trigged properties, including CO release and antimicrobial activity. Host-guest chemistry of air-sensitive organometallic complexes is therefore a promising technique that can be used to broaden the scope of metal-containing polymers (MCPs) with processable novel functions.

Synthetic approaches towards structurally-defined electrochemically and (photo)redox-active polymer architectures

This review details synthetic strategies leading to structurally-defined electrochemically and (photo)redox-active polymer architectures,e.g.block, graft and end functionalized (co)polymers.

Facile preparation of a novel nickel-containing metallopolymer via RAFT polymerization

While the metallocene polymers were comprehensively studied, other metallopolymers are rarely explored. The major challenge is the lack of a synthetic platform for the preparation of metal coordinated derivatives, monomers, and polymers. Therefore, the development of a facile synthesis of new metal coordinated monomers and polymers is critically needed. A novel successfully synthesized methacrylate-containing nickel complex is reported in this communication. Controlled RAFT polymerizations are further carried out to prepare a series of side-chain nickel containing polymers with different molecular weight and narrow Polydispersity Index (PDI). This new metallopolymer performs specific electrochemical and excellent thermal properties. This study provides a novel and convenient strategy to prepare metallopolymer with controllable molecular weight, which has potential applications in assembled, catalytic and magnetic materials.