Redox-active mesomorphic complexes from the ionic self-assembly of cationic polyferrocenylsilane polyelectrolytes and anionic surfactants

The concept of ionic self-assembly (ISA) has been employed to design and prepare new redox-active thermotropic liquid-crystalline materials. These ordered anisotropic materials in the bulk state were constructed from the complexation of a series of polyferrocenylsilane (PFS) polyelectrolytes with several oppositely charged surfactants. The structural characterization of the self-assembled materials was performed using a variety of techniques including FTIR, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarized optical microscopy (POM), small- and wide-angle X-ray scattering (SAXS and WAXS), transmission electron microscopy (TEM) and UV-vis spectroscopy. Results showed that strong coulombic attractions between the starting building blocks resulted in the formation of ordered mesostructures with average periodicities of 2-3 nm. The precise phase thickness of both the PFS and surfactant layers was quantitatively determined using a one-dimensional correlation function. Moreover, the redox properties of the mesomorphic organometallic PFS polyelectrolyte-surfactant complexes were systematically investigated using cyclic voltammetry (CV) and chemical redox methods. The versatility of this ISA technique also allowed the incorporation of a photoactive azobenzene-containing surfactant, resulting in ordered mesostructures with potential optoelectronic applications.