New triphenylene based discotic liquid crystals with mixed tails: Molecular symmetry and wide columnar mesophase range

A series of new trialkoxytrialkanoyloxytriphenylene TP(OCnH2n+1)(3)(OCOCmH2m+1)(3) (5a-5e) (n=m+ 1 =48) discotic liquid crystals were prepared and their mesomorphic properties were investigated using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The symmetrical and shorter chain triphenylenes display higher melting points and clearing points, more highly ordered and stable columnar mesophase than the asymmetrical and longer chain triphenylenes respectively.