Crystals of ferrocene-containing rotaxane undergo thermally induced reversible phase transition without losing the crystallinity. It involves conformational change of an end group of the axle component molecule and shift of the position of PF6 and AsF6 counter ions to a specific direction. Motion of the cationic rotaxane and the counter anion is controlled by crystallographic symmetry. As a second topic, hydrogel formation of the organic rotaxane is also presented. A mixture of alkylpyridiniums with 3,5-dimethoxyphenyl end group, [py-N-(CH2)10OC6H3-3,5-(OMe)2]+(Cl-) and a-CD in aqueous solution produced a hydrogel. The sol-gel transition temperature is controlled minutely by changing the concentration of the alkylpyridinium and cyclodextrin. The gel formation is enhanced by formation of [3]rotaxane from one axle and two cyclic component molecules.

Rotaxanes in condensed phase

245th National Meeting (2013)

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