par Lehmann, Matthias 
;Levin, Jérémy
Référence Molecular crystals and liquid crystals, 411, page (273/[1315]-281/[1323])
Publication Publié, 2004
;Levin, Jérémy Référence Molecular crystals and liquid crystals, 411, page (273/[1315]-281/[1323])
Publication Publié, 2004
Article révisé par les pairs
| Résumé : | Encouraged by theoretical predictions that nematic phases formed from V-shaped compounds could be biaxial, shape-persistent phenylene ethynylene arms linked by 1,3-phenylene, 4,4′-diphenylenemethane and 3,6-fluorenone units have been synthesized. Crystallisation and micro-segregation is prevented by 2, 5-alkoxy substitution on the middle benzene ring of the arms. The specific molecular engineering, i.e. variation of peripheral substituents (H, CN) and different lengths of lateral alkoxy chains, lead to enantiotropic nematic liquid crystals over a wide temperature range for fluorenone containing materials II3d and mixtures of II3d with non-mesogenic II3b. These mesophases solidify at ambient temperature, and form nematic glasses. |
