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
| Autor: | Ayumi Watarai, Mikio Yasutake, Kohei Ishikawa, Kazuchika Ohta |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Journal of Porphyrins and Phthalocyanines. 22:693-715 |
| ISSN: | 1099-1409 1088-4246 |
| DOI: | 10.1142/s108842461850092x |
| Popis: | 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 C[Formula: see text]H[Formula: see text]O 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 C[Formula: see text]-substituted dyads {1a~1c-16}. The letters of a, b and c mean substitution positions of C[Formula: see text]H[Formula: see text]O group at [Formula: see text], [Formula: see text] and [Formula: see text], respectively. We have investigated the influence of both substitution position of the alkoxy chains and the kind of terminal groups (OH, OFBA and C[Formula: see text] 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 2[Formula: see text] = 1.1[Formula: see text] 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 substitution positions of the alkoxy group. Moreover, we revealed that both the m-substituted derivative 1a-16 and the m,p-substituted derivative 1c-16 gave Peak H, but that only the p-substituted derivative 1b-16 did not give Peak H among these three dyads {1a~1c-16}. From the temperature-variable small angle X-ray diffraction measurements for the m,p-substituted derivative 1c-16 using two different sample preparation methods, we proved that the Peak H originates from a helical pitch of fullerenes. We also pointed out that the m-substituted long alkoxy chains are at least needed to form the helical supramolecular structure in the present (PhO)[Formula: see text]PcM-C[Formula: see text]-based dyads. |
| Databáze: | OpenAIRE |
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