Síntese e caracterização de cristais líquidos curvados derivados da dibenzalacetona

Abstract

Liquid crystals (Lcs) are substances that show simultaneously fluidity- characteristic of liquid state – and molecular organization and anisotropy – characteristic of the solid state. They are widely investigated both in the scientific perspective, where it seeks new applications, more versatile materials and to deepen the area knowledge, as well as in technological research, in the production of more robust and efficient optoelectronic devices. Therefore, the objective of this work was to synthesize and investigate Lcs derived from the (1E,4E)-1,5-bis(4-hydroxyphenyl)penta-1,4-dien-3- one, a naturally curved and easily obtainable bent-core, with a strong transverse dipole moment and unexplored in Lcs. The rigid core was synthesized through a double aldol condensation between acetone and 4-hidroxybenzaldehyde, in acidic medium. A direct alkylation reaction of the core generated the product O-C12, while esterification generated E-C12, a long product, having their purity confirmed by ¹H NMR. The mesomorphic properties of the products were investigated by POM and DSC. The product O-C12 did not present liquid-crystalline characteristics, melting directly to the liquid state. On the other hand, the largest product E-C12 showed a complex behavior, with a typical bent-shaped mesophase These preliminary results demonstrate the versatility of this core being a promising candidate to more advanced optoelectronics studies.