The Influence of Lithium Perchlorate on Discotic Liquid Crystals and the Ion Conduction of their Mixtures

A C3-symmetric trimesic amide derivative with peripheral oligo(ethylene oxide) side chains (compound 1) shows discotic mesomorphism in a broad temperature range due to stacking of the extended core (Tg ∼ -50[ddot]C; Tcl ∼ 240[ddot]C). Mixtures of 1 and lithium perchlorate (LiClO4) also exhibit liquid crystalline (LC) properties as shown by polarization microscopy, DSC and X-ray diffraction studies. An increase of the Tg as well as a decrease of the clearing temperature are observed with increasing salt concentration. The ion conducting properties of the LiClO4-mixtures of 1 have been measured by complex impedance spectroscopy; promising levels of conductivity, up to 10−6 S/cm at room temperature, have been recorded.