We have developed various analytical methods based on ion exchange phenomena and through the elucidation of the molecular processes of ion exchange. This paper particularly focusses on polyether complexation and its utilization to the modification of selectivity in ion exchange separation. Ion exchange chromatography is not only useful for the separation of ions but also is an efficient approach for probing various reactions and equilibria that cannot be evaluated by other methods. If a separation system is appropriately designed, we can extract information on secondary equilibria, which occur in a mobile phase and are not affected by retention processes. Thus, we can use a chromatographic column as a laboratory for solution chemistry. This approach is particularly efficient when impure or mixed samples are handled. The complexation of acyclic polyethers is a good example that manifests the efficiency of the present chromatographic approach. Modification of ion exchange selectivity with polyether complexation on the stationary phase is also discussed.

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 Derived from our wide experience in the production and analysis of ultra-pure water, we developed a new series of ion exchange resins designed for the purification of chemicals & organic solvents used in the electronics industry. Here we will introduce the properties of two newly developed ion exchange resins, the “Amberlyst DRY” series, which are dry resins for non-aqueous liquids, and the “Orlite DS” series, which are clean resins with extremely low metal leaching. We will also report on some applications for these resins.

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 Realizing a synthetic model for a light-harvesting (LH) antenna is challenging from the viewpoint of elucidating electron transfer processes, high efficiency for electron charge separation, and efficient photo energy usage. The crystal structure of the LH antenna complex (LH2) from the Rhodopseudomonas acidophila strain 10050 shows that the active assembly consists of two concentric cylinders of helical protein subunits enclosing the dimeric pigment molecules. Developing a model compound through noncovalent bonds in water is challenging from the viewpoint of supramolecular architecture. In this study, we successfully prepared a β-cyclodextrin-linked porphyrin zinc complex, and observed the addition of potassium 2-bromo-1,4-naphthoquinone-3-sulfonate to the β-cyclodextrin-linked porphyrin solution and the structure of the complex by means of ¹H NMR spectroscopy. Using Job's method, 1:1 stoichiometry was estimated for the system. Moreover, the inclusion complex was discussed in detail.

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