Crystal structures of mesogens with a bent molecular shape: 4,6-dichloro-1,3-phenylene bis-[4-(4-n-alkyloxy-phenyliminomethyl)benzoates] |
| |
Authors: | H Hartung A Stettler W Weissflog |
| |
Institution: | Martin-Luther-Universität Halle-Wittenberg, Institut für Physikalische Chemie, Mühlpforte 1, D-06108 Halle, Germany |
| |
Abstract: | The crystal and molecular structures of hexyloxy (3a) and heptyloxy homologues (3b) of mesogenic 4,6-dichloro-1,3-phenylene bis4-(4-n-alkyloxy-phenyliminomethyl)benzoates] have been determined by X-ray analyses. Both compounds crystallize in the triclinic space group
with two molecules in unit cells of following dimensions. 3a: a=8.340(2), b=13.143(4) and c=19.364(6) Å; =96.36(4), β=93.33(4) and γ=103.07(1)°; 3b: a=8.738(2), b=15.850(4) and c=17.618(5) Å; =115.73(2), β=90.82(2) and γ=95.49(2)°. The structures were solved by direct methods and refined on F2 to R values of R1=0.046 (3a) and 0.094 (3b). The molecular structures of 3a and 3b are discussed in detail, especially in view of the correlation between molecular conformation (banana- or rod-shaped molecules) and liquid crystalline behaviour (observed mesophases). It can be shown for 3a and 3b that the molecules are not strongly bent and not so far from the rod-like shape. Crystal packing of the mesogens is characterized by a parallel arrangement of the strongly interlocked molecules. |
| |
Keywords: | Crystalline mesogens Liquid crystals Crystal structure Molecular structure Banana-shaped mesogens |
本文献已被 ScienceDirect 等数据库收录! |
|