Star-shaped oligobenzoates with a naphthalenechromophore as potential semiconducting liquid crystal materials?

Abstract

A series of star-shaped non-C₃-symmetrical mesogens containing one naphthalene chromophore at a defined position have been synthesised to study the influence of phase symmetry and nano-segregation on the order of the chromophores and their interactions in potential semiconducting materials. Structural investigations reveal a rich mesomorphism from columnar hexagonal, columnar rectangular, lamellar to cubic phases depending on the type of oligobenzoate arms attached to the core. Although the decoration of the naphthalene containing arm with peripheral semi-perfluorinated chains results in a confinement of the chromophores to the interface between cores and perfluorinated units, the naphthalenes do not strongly interact among themselves as evidenced by the photophysical studies. The latter is attributed to the E-shaped conformer and the increased intra-columnar separation owing to the fluorinated chains.