Symmetric bent-shaped liquid crystal dimers showing transitions between optically uniaxial and biaxial smectic phases |
| |
| Authors: | Claudia M Hegguilustoy Maria B Darda Rosana S Montani Benoît Heinrich Bertrand Donnio Daniel Guillon |
| |
| Institution: | 1. INQUISUR, Departamento de Química, Universidad Nacional del Sur, Bahía Blanca, Argentina;2. Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR7504), Strasbourg Cedex 2, France;3. Complex Assemblies of Soft Matter Laboratory (COMPASS), CNRS-Solvay-University of Pennsylvania (UMI 3254) CRTB, Bristol, PA, USA |
| |
| Abstract: | We report the synthesis of a new homologous series of symmetric bent-shaped liquid crystal dimers bearing oxybiphenylcarboxylate mesogens linked by a pentamethylene spacer. The dimers were characterised by optical, thermal, X-ray diffraction and computational techniques. Shorter dimers showed an I-N-SmA-SmC phase sequence with strong first-order phase transitions. For the longer dimers, the unconventional uniaxial SmA phase present in shorter members collapsed. A 9:1 binary mixture of a bent dimer with a non-mesogenic dimer exhibited upon the SmA-SmC phase transition a maximum layer contraction of 1%. |
| |
| Keywords: | symmetric dimers bent-shaped smectic phase orthogonal phase de Vries behaviour |
|
|
