Liquid-crystalline functional carbazole and naphthalene platforms

Abstract

Two novel families of highly functionalized molecules consisting of a central carbazole or naphthalene core carrying actionable acid functions and linked to gallate platforms equipped with three long alkoxy chains have been rationally designed. The presence of amide tethers and chelating rigid fragments generate a new class of luminescent mesomorphic materials. Platforms bearing long paraffin chains (n = 12 and 16) self-organize into columnar liquid crystalline phases in which the columns are arranged according to a 2D oblique, rectangular or hexagonal lattice symmetry as deduced from powder XRD experiments. FT-IR studies confirm that the common driving force for aggregation and micro-segregation in the mesophase is due to the occurrence of a tight intermolecular H-bonded network. Spectroscopic measurements show that these platforms are luminescent in solution and in the solid state. Due to the synthetic availability of carbazole and naphthalene rigid cores and the simplicity by which these platforms can be graphed, this methodology represents a practical alternative to the production of fluorescent and mesomorphic materials.