| dc.description.abstract | In this thesis, we investigated the relationship between inter-molecular interactions and mesomorphic properties through substitution partial structures. All compounds were characterized by 1H, 13C-NMR spectroscopy and element analysis. The phase behaviors of these compounds were studied by polarized optical microscopy (POM), differential scanning calorimetry (DSC), powder X-ray diffraction (XRD).
Ligand 2a were derivated from salicyladimines. Pd2+ and VO2+ ions formed mononuclear complexes (1a, 1b), whereas, Cu2+ ion formed binuclear complexes (1c) . Series 2a, 1a and 1b exhibited SmA phase. We also compared mesomorphic properties with similar structures.
Ligand 4a were derivated from unsymmetric pyrazoles. Froming four coordination complexes (3a) with Cu2+ ions, whereas, Al3+ ions fromed six coordination complexes (3b). Ligands and complexes exhibited smectic phase. Compared with similar structures, we proved that it is helpful for formation of mesophase by increasing rigid core proportion.
Finally, series 6a and 6b were oxadiazole and thiadiazole derivatives. 6a exhibited a short range of nematic (N) or smectic C (SmC) mesophases. The thiadiazole derivatives, 6b, formed nematic (N), smectic A (SmA) and smectic C (SmC) phases over a wide range of temperatures.
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