| dc.description.abstract | In this thesis, we report the synthesis, characterization and mesomorphic properties of two novel series of new mesogenic derivatives based on 3-Alkoxy-6-[(4-alkoxy-2-hydroxy-phenylimino)- methyl]-benzene-1,2-diol 1 and metal complexes of 2,3-dialkoxyl-6-(6- alkoxyl-benzooxazol-2-yl)-phenol. These compounds were all characterized by 1H-NMR and 13C-NMR spectroscopy, and their mesomorphic properties were studied by differential scanning calorimeter (DSC), polarized optical microscopy (POM) and powder XRD diffraction.
For the first series of 3-Alkoxy-6-[(4-alkoxy-2-hydroxy-phenylimino) -methyl]-benzene-1,2-diol 1 and 2-Hydroxy-4- alkoxyl-N-(2-hydroxy-4- alkoxybenzylidene)anilines 2, all compounds exhibited smectic phases. Compounds 2 exhibited mesomorphic behavior similarly to compounds 1. In contrast, compounds 2 have higher melting points and wider mesogenic temperatures than 1.
In the second series of derivatives; the compounds of 2,3-dialkoxyl -6-(6-alkoxyl-benzooxazol-2-yl)-phenol as ligands were not mesogenic. However, the zinc(Ⅱ) complexes exhibited columnar rectangular (Colr, P21) phases, as predicted for disc molecules. The melting point of zinc complexes is ca. 30~80 ℃ higher than their metal-free ligands. However, palladium(Ⅱ) and copper(Ⅱ) complexes were not mesogenic. | en_US |