EFFECT OF LINKER CHEMISTRY AND TERMINAL SUBSTITUENTS ON THE LIQUID CRYSTALLINE PROPERTIES OF BIS(AZOBENZENE) MESOGENS

Abstract

Azobenzene upon photochemical E/Z isomerization changes both its shape and size. The E-azobenzene moiety falls in the class of calamitic liquid crystalline mesogens, producing a wide variety of mesophases. Two series of linear bis(azobenzene) compounds, one with phenyl benzoate linkage and the other with benzyl benzoate linkage were synthesized. The termini of these molecules ranged from a dodecyloxy chain to hydrophobic amphiphilic dendrons up to first generation. We determined the effects of both the linkages and generation number on the mesogenic properties of these compounds. Our results show that the mesogenic behavior of these bis(azobenzene) compounds are highly dependent on the linkages between individual azobenzenes and that for the bis(azobenzene) compounds of the phenyl benzoate series, generation number had an effect on the liquid crystalline mesophase of the compounds