Synthesis and Properties of Novel Liquid Crystalline Compounds, 3,4,5-Trialkoxybenzoic Anhydride

Abstract

Novel liquid crystalline compounds, 3,4,5-trialkoxybenzoic acid anhydrides 1 were synthesized and the properties were investigated. The half-disk molecule 1 has two carbonyl groups which are in syn-parallel. In the process of organization of the columnar phase, to cancel the large dipole, a dimer generates from two molecules with anti-parallel manner, and the dimers are assembled into a column. Two types of dimerizations, uneven-parallelly (A) and perpendicularly (B) dimerized, are anticipated for the anti-parallel association. From powder X-ray diffraction, the diameters observed are shorter than those calculated in molecular modeling using MM2. In polarized-light microscopy, the textures indicated that the molecules are not tilt in the column. Accordingly, dimer B seems to be the reasonable model to explain the short lengths because the each molecule is tilt and the average director are parallel to the column.