Self assembled rotaxane and pseudo-rotaxanes based on β-cyclodextrin inclusion compounds with trans-1,4-bis[(4-pyridyl)ethenyl]benzene-pentacyanoferrate(II) complexes

Inclusion compounds of trans-1,4-bis[(4-pyridyl)ethenyl]benzene (BPEB) and their corresponding pentacyanoferrate(II) complexes with β-cyclodextrin have been studied in aqueous solution by 1H NMR and UV-Visible spectroscopy. All the inclusion compounds exhibit 1:1 stoichiometry is aqueous solution. In the presence of β-cyclodextrin, the binuclear {[Fe(CN)5]2(BPEB)]6- complex is gradually converted into rotaxane species bearing [Fe(CN)5]3- end groups, by a self assembly inclusion mechanism, as confirmed by 1H NMR spectroscopy. (author)