Novel methodology to control the adsorption structure of cationic porphyrins on the clay surface using the "size-matching rule"

Tsuyoshi Egawa, Hajime Watanabe, Takuya Fujimura, Yohei Ishida, Masafumi Yamato, Dai Masui, Tetsuya Shimada, Hiroshi Tachibana, Hirohisa Yoshida, Haruo Inoue, Shinsuke Takagi

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Abstract

Saponite-type clays that have different cation exchange capacities were successfully synthesized by hydrothermal synthesis. The structure and properties were analyzed by X-ray diffraction, X-ray fluorescence, 27Al NMR, FT-IR, thermogravimetric and differential thermal analysis, atomic force microscopy, and cation exchange capacity measurement. The intercharge distances on the synthetic saponite (SS) surfaces were calculated to be 0.8-1.9 nm on the basis of a hexagonal array. The complex formation behavior between SS and cationic porphyrins was examined. It turns out that the average intermolecular distance between porphyrin molecules on the SS surface can be controlled, depending on the charge density of the SS. In the case of tetrakis(1- methylpyridinium-4-yl)porphyrin (H 2TMPyP 4+), the average intermolecular distances on the SS surface can be controlled from 2.3 to 3.0 nm on the basis of a hexagonal array. It was also found that absorption maxima of porphyrins depend on the charge density of the SS. The adsorption behavior of porphyrin on the SS surface can be rationally understood by the previously reported "size-matching rule". This methodology using host-guest interaction can realize a unique adsorption structure control of the porphyrin molecule on the SS surface, where the gap distance between guest porphyrin molecules is rather large. These findings will be highly valuable to construct photochemical reaction systems such as energy transfer in the complexes.

Original languageEnglish (US)
Pages (from-to)10722-10729
Number of pages8
JournalLangmuir
Volume27
Issue number17
DOIs
Publication statusPublished - Sep 6 2011

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ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

Cite this

Egawa, T., Watanabe, H., Fujimura, T., Ishida, Y., Yamato, M., Masui, D., ... Takagi, S. (2011). Novel methodology to control the adsorption structure of cationic porphyrins on the clay surface using the "size-matching rule". Langmuir, 27(17), 10722-10729. https://doi.org/10.1021/la202231k