title: A liquid crystalline supramolecular complex of C60 with a cyclotriveratrylene derivative
abstract: Cyclotriveratrylene (CTV) derivatives substituted with 9 (1) or 18 (2) long alkyl chains have been prepared. Whereas no liquid crystalline behavior has been observed for 1, the CTV derivative 2 has mesomorphic properties. Indeed, at room temperature compound 2 exhibits a nematic phase characterized by cybotactic groups with a local lamello-columnar order. Both CTV derivatives 1 and 2 are able to form supramolecular complexes with C60 in the solid state. In both cases, the 2:1 host-guest species have been obtained as brown compounds. No liquid crystalline behavior was observed for the supramolecular complex [C60 is included in (1)2]. In contrast, observation of the brown product obtained from C60 and the CTV derivative 2 directly after preparation by polarized optical microscopy revealed a fluid birefringent phase at room temperature. When the sample is heated above 70 degrees C, the birefringence of the texture under the microscope disappears and the X-ray diffraction pattern is transformed into a pattern characteristic of a cubic phase. For the first time in thermotropic liquid crystals, the space group of this cubic phase can be assigned as I4(1)32.
authors.affiliation: Groupe des Materiaux Organiques, Institut de Physique et Chimie des, Materiaux de Strasbourg, Universite Louis Pasteur and CNRS, France.
authors.initials: D
authors.lastname: Felder
authors.initials: B
authors.lastname: Heinrich
authors.initials: D
authors.lastname: Guillon
authors.initials: JF
authors.lastname: Nicoud
authors.initials: JF
authors.lastname: Nierengarten