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A Liquid Crystalline Supramolecular Complex of C 60 with a Cyclotriveratrylene Derivative
Author(s) -
Felder Delphine,
Heinrich Benoît,
Guillon Daniel,
Nicoud JeanFrançois,
Nierengarten JeanFrançois
Publication year - 2000
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20001002)6:19<3501::aid-chem3501>3.0.co;2-0
Subject(s) - thermotropic crystal , liquid crystal , supramolecular chemistry , crystallography , phase (matter) , polarized light microscopy , derivative (finance) , birefringence , texture (cosmology) , materials science , optical microscope , alkyl , fullerene , chemistry , liquid crystalline , crystal structure , organic chemistry , scanning electron microscope , optics , physics , optoelectronics , composite material , artificial intelligence , computer science , financial economics , economics , image (mathematics)
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 C 60 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 [C 60 ⊂( 1 ) 2 ]. In contrast, observation of the brown product obtained from C 60 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 °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 I 4 1 32.