Various mechanically interlocked molecules such as rotaxanes and catenanes have been prepared toward future realization of molecular machines. Moreover, intense recent research interest has been focused on technological applications of rotaxanes and catenanes as a molecular sensor and a catalyst.
A macrocycle having a bisamide and a half dibenzo-crown ether component was newly synthesized and its complexation behavior toward neutral phenanthroline derivatives is reported. The macrocycle can bind phenanthroline derivatives very strongly through the hydrogen bonding and π-electron interactions, yielding pseudorotaxane structures. The inclusion complexes show a pH-controllable reversible threading-dethreading molecular switching property.
A new type of cryptand-based pseudorotaxane was prepared, utilizing a novel cryptand incorporating two aromatic rings as a wheel component, combined with various bipyridinium salts as the axle component. These pseudorotaxanes exhibited charge-transfer absorption at approximately 380 nm due to π-electron interactions between the cryptand and the bipyridinium salt. Upon addition of one equivalent of sodium ion to the pseudorotaxane, this absorption was disappeared as a result of displacement of the bipyridinium salt by the sodium.

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When a system is open to outer environment and maintained in far-from-equilibrium condition, various self-organized states called dissipative structures are generated by the growth of fluctuation as they are observed in living systems. When a viscous liquid is spread on a solid substrate, no flat surface but the one having spatially periodic stripe patterns parallel to the spreading direction are usually formed. The pattern formation is due to the growth of morphological fluctuation of the interface between air and liquid in far-from-equilibrium condition generated during the formation of liquid layer. The growth of morphological fluctuations of interfaces is called fingering and the phenomenon is extensively observed in industrial production processes that involve in surface formations. We have developed the technology for inhibiting the generation of fingering in order to involve in establishing the in vitro determination method for sunscreen efficacy and in achieving the technological innovation in the rotary atomizer for car body painting. In addition, technology for fabrication of highly water-repellent surface has been developed by utilizing the spontaneous pattern formation by the viscous fingering.

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Surfactants are used in many applications, such as detergents, paints, toiletries and pharmaceuticals. The development of surfactants with excellent surface-active properties, additional functions, or good biodegradability has been desired. Therefore, chemocleavable surfactants, which decompose to give nonsurface-active species or other surfactants with different properties after fulfilling their original functions, have become the focus of great interest in the field of surfactant chemistry. In this review, chemocleavable surfactants bearing a 1,3-dioxolane ring or ester group were prepared from 1-O-alkylglycerols without any expensive reagents or special equipment. We clarified that they have good surface-active properties, and the decomposition function under acid or alkali conditions. Their biodegradabilities were higher than that of sodium dodecanoate. We used these surfactants as emulsifiers in emulsion polymerization. After the reaction, the emulsifier was decomposed by the addition of HCl or NaOH. And then the polymer was obtained easily. We discussed their detergency for clothes.

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