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

✍ Scribed by Michaël Even; Benoit Heinrich; Daniel Guillon; Dirk M. Guldi; Maurizio Prato; Robert Deschenaux

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 235 KB
• Volume: 7
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/1521-3765(20010618)7:12<2595::aid-chem25950>3.0.co;2-a

✦ Synopsis

Grafting of a ferrocene-containing liquid-crystalline malonate derivative to C 60 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 la-mellar phase is characterized by a microsegregation of the different units (ferrocene, fullerene, and cholesterol) in distinct sublayers. In such a smectic A phase, C 60 imposes the arrangement of the other molecular moieties. Photo-physical 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.