title: Reversible vesicles based on one and two head supramolecular cyclodextrin amphiphile induced by methanol.
abstract: Reversible vesicles based on supramolecular inclusion of hydroxypropyl-beta-CD (HPbetaCD) and N,N'-bis(ferrocenylmethylene)-diaminohexane (BFD) were prepared in water and methanol-water mixtures. The inclusion stoichiometry of HPbetaCD with BFD was in a molar ratio of 2:1, which could be named as 'two head' supramolecular amphiphile when the solvent was water. However, the inclusion stoichiometry of HPbetaCD with BFD would tend to be a molar ratio of 1:1 based on introduction of methanol to the solvent, especially when the volume ratio of methanol and water was more than 1:4, which could be named as 'one head' supramolecular amphiphile. The inclusion compounds could switch between 'one head' and 'two head' conformations by changing the methanol concentration of the solvents. The vesicles were also found to be responsive to the stimulus of external molecules. When the inclusion ability between HPbetaCD and an external guest was relatively stronger, the vesicles were easily destroyed. Furthermore, the vesicles disappeared after adding an oxidizing agent. NMR was used to confirm the conformation of the mixture of HPbetaCD and BFD in water. The structure and morphology of the vesicles were characterized by TEM and DLS. The vesicles may be used in smart materials, drug delivery and molecular recognition.
authors.affiliation: School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: An
authors.forename: Huacheng
authors.initials: H
authors.lastname: Zhang
authors.forename: Lizhen
authors.initials: L
authors.lastname: Sun
authors.forename: Aiyou
authors.initials: A
authors.lastname: Hao
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Hao
authors.forename: Feifei
authors.initials: F
authors.lastname: Xin
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D003505:Cyclodextrins / Q000737:chemistry*; D006586:Hexanes / Q000737:chemistry; D008027:Light; D008567:Membranes, Artificial; D000432:Methanol / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D008968:Molecular Conformation; D012542:Scattering, Radiation; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D003505:Cyclodextrins; D006586:Hexanes; D008567:Membranes, Artificial; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000432:Methanol