Effect of asymmetric substitution on the mesomorphic behaviour of low-melting viologen salts of bis(trifluoromethanesulfonyl)amide

摘要: We report on the synthesis and characterisation of novel ionic liquid crystals liquids based asymmetric viologen salts bis(trifluoromethanesulfonyl)amide (Tf2N−). The thermotropic behaviour has been thoroughly characterized by DSC, X-ray diffraction polarized light optical microscopy. occurrence smectic mesophases temperature range over which they are stable discussed as a result asymmetry dications. Strongly systems, not showing mesomorphism, have rather low melting point (just beyond 40 °C) while slightly samples exhibit phase with wide stability, from about 0 °C up to above 140 °C, thus increasing stability mesophase observed for symmetric compounds. Finally, we lyotropic in non-polar solvents, such benzene, where clathrates found.