Redox properties future research

Nevertheless, despite these breakthroughs, it is very apparent that the incorporation of metallocenes other than ferrocene into polymer structures has been developed to a much lesser extent, and for the 21st century, this still remains a substantial synthetic challenge. This is despite the fact that many other metallocenes are readily accessible, stable, and also exhibit interesting physical, redox, and catalytic properties [2, 4, 9]. The lower ease of derivatization of most other metallocenes compared to ferrocene and, in some cases (e.g. that of ruthenocene), the problem of relative expense, have clearly been important factors which have held back synthetic developments in this area. Nevertheless, it is anticipated that the development of mainpolymers based on other metallocenes is likely to be very fertile ground for future research. 

Furthermore, metals present additional intrinsic properties, such as redox reversibility, magnetism and luminescence. It is, therefore, possible to take benefit from these peculiarities for the design of redox-controlled NLO switches as illustrated in this chapter or for the elaboration of materials combining two or more properties. This latter field of research is in its infancy but it is possible to anticipate many improvements in the future for the elaboration of multifunctional molecular material optimising simultaneously all the wonderful capacities of metals. 

---