PROPERTIES OF NONLINEAR SUPRAMOLECULAR LIQUID-CRYSTALS CONTAINING THIOPHENEDICARBOXYLIC ACIDS

Novel mesogenic supramolecules have been constructed from the 2:1 mola r ratio of trans-4-alkoxy-4'-stilbazoles CnPS (1) complexed with 2,5-t hiophenedicarboxylic acid THDA (4) to form the kinked hydrogen-bonded (H-bonded) complexes (CnPS)(2)-THDA. The analogous H-bonded complexes (CnPP)(2)-THDA consisting of the 2:1 molar ratio of 4-alkoxypyridines CnPP (2) and THDA (4) are also compared. In contrast to linear complex es (CnPS)(2)-TA prepared from the 2:1 molar ratio of CnPS (1) and tere phthalic acid TA (5), supramolecular liquid crystals with kinked molec ular structures (CnPS)(2)-THDA are generated by introducing the thioph ene unit into the H-bonded complexes. In addition, the chiral complex (C5PS)(2)-THDA composed of an optically active proton acceptor (S)-(- )-4-( 2-methylbutoxy)-4'-stilbazole C5PS (3) and THDA (4) (2:1 molar ratio) is reported. Significantly, the first thiophene-based supramole cular liquid crystals have been constructed in this study, and the mes ogenic properties of the supramolecules can be easily adjusted not onl y by the nonlinear shape of the thiophene unit but also by the dipole moment derived from the lone-pair electrons of the sulphur hetero-atom .