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931.
Supramolecular Interaction of Fullerenes with a Curved π‐Surface of a Monomeric Quadruply Ring‐Fused Porphyrin
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Yuta Saegusa Dr. Tomoya Ishizuka Dr. Tatsuhiro Kojima Dr. Shigeki Mori Prof. Dr. Masaki Kawano Prof. Dr. Takahiko Kojima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5302-5306
Molecular binding of fullerenes, C60 and C70, with the ZnII complex of a monomeric ring‐fused porphyrin derivative ( 2 ‐py) as a host molecule, which has a concave π‐conjugated surface, has been confirmed spectroscopically. The structures of associated complexes composed of fullerenes and 2 ‐py were explicitly established by X‐ray diffraction analysis. The fullerenes in the 2:1 complexes, which consist of two 2 ‐py molecules and one fullerene molecule, are fully covered by the concave surfaces of the two 2 ‐py molecules in the crystal structure. In contrast, in the crystal structure of the 1:1 complex consisting of one 2 ‐py molecule and one C60 molecule, the C60 molecule formed a π–π stacked pair with a C60 molecule in the neighboring complex using a partial surface, which was uncovered by the 2 ‐py molecule. Additionally, the molecular size of fullerene adopted significantly affects the 1H NMR spectral changes and the redox properties of 2 ‐py upon the molecular binding. 相似文献
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Yuta Otsuka Masaki Takeuchi Makoto Otsuka Besim Ben-Nissan David Grossin Hideji Tanaka 《Colloid and polymer science》2015,293(10):2781-2788
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Frontispiece: Supramolecular Interaction of Fullerenes with a Curved π‐Surface of a Monomeric Quadruply Ring‐Fused Porphyrin
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Masaki Wakagawa Mariko Hayashi Shigeki Kuroki Mitsuru Satoh 《Journal of Polymer Science.Polymer Physics》2009,47(21):2132-2139
Bound states of counterions during the coil‐globule transition of poly(acrylic acid) in water/organic solvent mixtures were investigated by NMR spectroscopy of alkali metal cations (Li+, Na+, Cs+). Accompanying the transition, the line widths of the respective NMR peaks significantly increased with increasing the organic solvent composition in the medium. Although this line width broadening suggests that some specific counterion binding with desolvation is involved with the coil‐globule transition, the most marked broadening was observed in higher organic solvent compositions than those of the coil‐globule transition region detected by the viscometry. Namely, the specific counterion binding with desolvation proceeds even after the polymer chain collapsed. This means in turn that such a strong counterion binding is not a prerequisite for the coil‐globule transition, at least at the stage of the onset. For the Li+/Cs+ mixed counterion system in 60 vol % DMSO, where our previous conductivity data suggested that the specific counterion binding occurred only for Cs+ during the coil‐globule transition induced on mixing with Li+, a significant increase in the line width was also observed only for Cs+. The coincidence between the conductivity and the NMR results for the Li+/Cs+ mixed counterion system strongly supports a working hypothesis, “size‐fitting effect,” that has been proposed to determine the counterion specificity observed for the conformational transitions of polyelectrolytes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2132–2139, 2009 相似文献
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