Electro-optical-coloration active polymers: Electrochemical polymerization in chiral liquid crystals supported by an α-tocopherol derivative

Abstract

Electrochemical polymerization was performed in a cholesteric liquid crystal (CLC) with an α-tocopherol (vitamin E) derivative as a chiral inducer to yield electroactive polymers exhibiting dynamic electrochemical-driven changes in optical activity. Materials possessing multiple asymmetric centers with long alkyl chains can be conveniently obtained using vitamins as chiral substances. First, an α-tocopherol derivative was synthesized as a chiral dopant (chiral inducer) to induce a CLC from a nematic liquid crystal. Thereafter, π-conjugated polymers were electrochemically prepared in the CLC with the α-tocopherol derivative. The fingerprint texture derived from the CLC was successfully transcribed to the polymers, and molecular asymmetric imprinting polymerization was achieved. Furthermore, the oxidized (doped) and reduced (dedoped) forms of the polymers were subjected to ultraviolet–visible and circular dichroism analyses. Electrochemical polymerization in the helical CLC resulted in molecular aggregation–imprinted chirality in the polymers. The chiral information was transferred from vitamin E to the nematic liquid crystal and resulting polymers.