Properties of polyferrocenylsilane dissolved in ionic liquids

The main block of polyferrocenylsilane (PFS) polymer is composed of ferrocene molecules bridged by silicon atoms. In this study, we found that PFS was insoluble in an imidazolium-based ionic liquid. On the other hand, PFS dissolved easily in an ionic liquid based on pyrazolium, under ordinary conditions and at room temperature. Furthermore, dissolving PFS in this ionic liquid afforded a p-type doped material. We found that the secondary amine in pyrazolium acted as an oxidant for ferrocene, allowing the PFS to dissolve in the ionic liquid. The measured thermal properties of the PFS-ionic liquids allowed us to show the existence of an attractive interaction between PFS and the ionic liquid.