Polycatenar vinamidinium salts - low-melting ionic mesogens displaying columnar mesomorphism

A few hexacatenar mesogens derived from vinamidinium salts were synthesized and their mesomorphic properties investigated by optical polarization microscopy (POM), differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). In contrast to the free vinamidine and the corresponding vinamidinium perchlorate salt, the chloride, bromide and triflate derivatives gave rise to hexagonal columnar mesophases with remarkable phase stability and melting temperatures just slightly above room temperature.