Shirakawa Michihiro, Fujita Norifumi, Shinkai Seiji
Department of Chemistry & Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan.
J Am Chem Soc. 2003 Aug 20;125(33):9902-3. doi: 10.1021/ja035933k.
A tetraphenylporphyrin (1b) bearing amide groups at the 3,5-positions of the meso-phenyl groups is assembled into a two-dimensional sheetlike structure and acts as an organogelator. When [60]fullerene was added, the sheetlike structure was dramatically changed into a one-dimensional fibrous structure, and both the gelation ability and the gel stability were improved. The stoichiometry between [60]fullerene and 1b was determined to be 1:2. Examination utilizing SEM and TEM observations, UV-vis and ATR IR spectral analyses, and XRD analysis revealed that an amide-amide hydrogen-bonding interaction creates a cavity, the size of which is complementary to that of [60]fullerene, and these cavities are connected by another amide-amide hydrogen-bonding interaction to provide a one-dimensional multicapsular structure. This is a novel example that the superstructure constructed in an organogel system is drastically changed by added [60]fullerene.