Sulfonatocalix[4]arene lowers the critical aggregation concentration of fluorocarbon surfactant pronouncedly by a factor of ca.100 to form binary amphiphilic aggregates on the basis of host-guest complexation,which was identified by1H NMR spectroscopy,fluorescence spectroscopy,optical transmittance spectroscopy,dynamic laser scattering,high-resolution transmission electron microscopy,scanning electron microscopy,and surface tension experiments.Moreover,the resulting aggregates can respond to external stimuli,including temperature and inclusion of competitor guest.Therefore,the present system may have potential applications in drug delivery systems.
A n-conjugated phenylaza-15-crown-5-triazol-substituted coumarin fluoroionophore 1 was synthesized by cop- per（I）-catalyzed Huisgen alkyne-azide 1,3-dipolar cycloaddition （CuAAC ＂click＂ reaction）. 1 can display selective fluorescence enhancement toward Fe3＋ over Hg2＋, Cr3＋ and the other metal ions in aqueous solution. In sharp con- trast, the fluorescence behavior between Fe3＋ and Hg2＋ is completely reversed in EtOH. That is, Hg2＋ gives the largest fluorescence enhancement over Cr3＋, Fe3＋ and the other metal ions.
A twin-axial hetero[5]pseudorotaxane was constructed based on 1-hexyl-4,40-bipyridinium guest 1 and cucurbit[8]uril（CB[8]）and a-cyclodextrin（a-CD）.In its structure,CB[8]included two bipyridinium units to realize the twin-axial mode,and the hexyl chain was threaded into the cavity of a-CD.The[5]pseudorotaxane contains two types of macrocyclic hosts while the single axial and twin axial modes co-exist in its structure.The transformation of[5]pseudorotaxane could be realized by the addition of acid and 2,6-dihydroxynaphthalene（HN）.
Li-Hua WangZhi-Jun ZhangHeng-Yi ZhangHai-Lang WuYu Liu
