Construction and radical cation stabilisation of a supramolecular dyad by tetrathiafulvalene-modified β-cyclodextrin and cucurbit[7]uril
摘要:
A tetrathiafulvalene (TTF)-modified -cyclodextrin derivative (3) was carefully designed and synthesised by the reaction of 2-(2-cycanoethylsulphanyl)-3,6,7-tris-(methylsulphanyl)tetrathiafulvalene (1) and mono-6-deoxy-6-iodo--cyclodextrin (2) in 49% yield, which was comprehensively characterised by 1H NMR, mass spectra and elemental analysis. TTF-modified -cyclodextrin (3) showed satisfactory water solubility up to ca. 1x10-3M. Furthermore, the interactions between the radical cation of 3 and cucurbit[7]uril were investigated by means of UV-vis spectroscopy, electron paramagnetic resonance, kinetic experiment and cyclic voltammetry. The results indicated that the introduction of the cucurbit[7]uril and cyclodextrin unit could promote a remarkable effect on the stability of TTF radicals generated by 1 equiv. of Fe3+ in aqueous media, and the radical cations encapsulated in cucurbit[7]uril at this state could be considered as stable and persistent ones.