A Mixed Fullerene-Ferrocene Thermotropic Liquid Crystal: Synthesis, Liquid-Crystalline Properties, Supramolecular Organization and Photoinduced Electron Transfer

Grafting of a ferrocene‐containing liquid‐crystalline malonate derivative to C60 led to the mixed fullerene–ferrocene material 1 which gave rise to a smectic A phase. Cholesterol was used as liquid‐crystalline promoter. X‐ray diffraction experiments and volumetric measurements indicated that 1 is organized in double layered structures. The corresponding supramolecular organization within the mesomorphic lamellar phase is characterized by a microsegregation of the different units (ferrocene, fullerene, and cholesterol) in distinct sublayers. In such a smectic A phase, C60 imposes the arrangement of the other molecular moieties. Photophysical studies revealed that electron transfer occurs from the donor ferrocene to the electron accepting fullerene. The formation of a long‐lived radical pair, with lifetimes of the order of several hundred nanoseconds, was confirmed by time‐resolved spectrometry, especially in the near infrared region, in which the radical anion of the fullerene moiety displays its characteristic fingerprint absorption. Grafting of a ferrocene‐containing liquid‐crystalline malonate derivative to C60 led to the mixed fullerene–ferrocene material 1, which gave rise to a smectic A phase. X‐ray diffraction experiments and volumetric measurements indicated that 1 is organized in double layered structures. Photophysical studies revealed that electron transfer occurs from the donor ferrocene to the electron‐accepting fullerene.