Following studies concerning mesomorphic heteroaromatic salts (pyryliu
m, thiopyrylium, dithiolium), we present here new thermotropic liquid
crystal materials based on 1,5-diazapentadienium (vinamidinium) salts
and on the pseudocyclic vinamidine system (1,5-diazapentadiene). The m
esomorphic properties of these systems have been studied by microscopi
c observations, DSC and X-ray diffraction.