Ferrocene-based polymers have wide application prospect in various fields such as electrochemistry, biomedicine, optics and so on, because of their unique structures and properties. The synthesis and exploration of the application of the ferrocene-based polymers have become a hot topic. In this review, we mainly focus on the synthesis and applications of the main-chain ferrocene-based polymers or side-chain ferrocene-based polymers. For synthesis of main-chain ferrocene-based polymers, polycondensation reaction, ring-opening polymerization and other synthetic methods have been summarized. For synthesis of side-chain ferrocene-based polymers, free radical polymerization, atom transfer radical polymerization (ATRP) method, reversible addition-fragmentation chain transfer (RAFT) polymerization have been applied. Finally, the future applications of ferrocene-based materials are prospected.

Contents
1 Introduction
2 Synthesis of main-chain ferrocene-based polymers
2.1 Polycondensation reaction
2.2 Ring-opening polymerization
3 Synthesis of side-chain ferrocene-based polymers
3.1 Free-radical polymerization
3.2 RAFT polymerization 3.3 ATRP method
3.4 Other synthetic method
4 Application of ferrocene-based polymers
4.1 Application in electrochemistry
4.2 Application in biology and medicine
4.3 Application in liquid crystal
4.4 Other applications
5 Conclusion