Columnar mesophases and phase behaviors of novel polycatenar mesogens containing bi-1,3,4-oxadiazole

A new series of liquid-crystalline bi-1,3,4-oxadiazole derivatives (2,2'-bis(3,4,5-trialkoxyphenyl)-bi-1,3,4-oxadiazole, BOXD-T-n, n=3, 4, 5, 6, 7, 8, 10, 14) were designed and synthesized. They have been confirmed to give rise to columnar mesophases. The columnar mesophases for BOXD-Tn (n=5, 6, 7, 8, 10) could be supercooled to -20 degrees C on the cooling runs. A room temperature Col(ho) phase was obtained for BOXD-T14. All BOXD-Tn exhibit good fluorescence properties either in cyclohexane or in solid state. (c) 2007 Elsevier Ltd. All rights reserved.