CONSTRUCTION OF COMPOUNDS WITH SPECIFIC STRUCTURES AND FUNCTIONS BY SELF-ASSEMBLIES

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We found that alpha-cyclodextrin forms complexes with poly (ethylene glycol) (PEG) of various molecular weights to give crystalline compounds in high yields, although beta-cyclodextrin did not form complexes with PEG.However, beta-cyclodextrin formed complexes with poly (propylene glycol) (PPG) to give stoichiometric compounds in high yields, though alpha-cyclodextrin did not form complexes with PPG of any molecular weights. gamma-Cyclodextrin formed complexes with poly (methyl vinyl ether) (PMVE), though alpha- and beta-cyclodextrin did not form complexes with PMVE.Spectroscopic studies of the complexes show that polymer chains are included in the cavities of cyclodextrins. Recently we found that cyclodextrins form complexes not only with hydrophilic polymers but also with hydrophobic polymers. alpha-Cyclodextrin, for example, formed complexes with oligoethylenes (OE) selectively. In contrast, gamma-cyclodextrin formed complexes with poly (isobutylene) (PIB) efficiently, although a-cyclodextrin did not form complexes with PIB.We have prepared polyrotaxanes in which many cyclodextrins are threaded on a polymer chain by capping the polymer chain ends with bulky substituents, such as 2,4-dinitrophenyl groups and 3,5-dinitrobenzoyl groups. The products were characterized by IR,UV,X-ray diffraction (powder), 1H NMR,13C NMR,13C-CP/MAS,and 2D NOESY NMR spectra.