Discotic liquid crystals of transition metal complexes 56: Synthesis of mesogenic phthalocyanine-fullerene dyads and influence of the substitution position of alkoxy chains and the kind of terminal groups on appearance of the helical supramolecular structure

We have synthesized twelve novel discotic columnar liquid crystals based on a phenoxy-group-substituted phthalocyaninato copper(II) complex having the same alkoxy chain of C16H33O at different positions in the phenoxy group: the parent compounds {0a~0c-16}and the OH-substituted compounds {3a~3c-16}, the OFBA-substituted compounds {2a~2c-16}and the C60-substituted dyads {1a~1c-16}. The letters of a, b and c mean substitution positions of C16H33O group at m−, p− and m,p−, respectively. We have investigated the influence of both substitution position of the alkoxy chains and the kind of terminal groups (OH, OFBA and C60) on the mesomorphism and the helical supramolecular structure, by using DSC, POM and temperature-variable small angle X-ray diffraction measurements. As a result, an additional big peak (Peak H) tends to appear at around 2𝜃 = 1.1deg in the X-ray diffraction patterns only for the dyads {1a~1c-16}but not for the other compounds, {0a~0c-16}, {3a~3c-16}and {2a~2c-16}, regardless of the substituti...