Star-Shaped Compounds with Oxadiazole Fragments. I. Influence of Molecular Structure Variation of Azo-Diphthalic Acids Derivatives on their Mesomorphism According to Prognosis Data

Abstract
The prognosis data on the columnar mesomorphism manifestation for new star-shaped azo-diphthalic acid derivatives with oxadiazole fragments and hyperbranched peripheral hydrophobic substituents were obtained. The data were analyzed and compared with the previously obtained results on the effect of structural modifications of such compounds with a smaller number of hydrocarbon radicals and lower branching. It was established that the presence of three hydrocarbon radicals in the peripheral phenyl rings in derivatives of azo-diortho- and azo-dimetaphthalic acid with oxadiazole fragments reduces the potential for columnar mesomorphism manifestation in comparison with the compounds having smaller number of such substituents. It was demonstrated that likewise the case of linear structure radicals presence, introducing a branched iso-butyl radical leads to a positive prognosis of mesomorphism.

Keywords: modeling, mesomorphism prediction, discotic mesogens, star-shaped heterocycles, polybasic acids, oxadiazoles