Amphiphilic cyclodextrin-calixarene conjugates 1 and 2 were synthesized from "click chemistry", and their self-assembly behaviors were investigated by transmission electron microscopy, and atomic force microscopy. The results obtained show that 1 and 2 can self-assemble to form distinctly different aggregations, and the morphology of aggregations critically relies on the polarity and hydrophilicity of the solvent.
Aggregation of 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin (TPPS) was investigated in complex micelles composed of poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP) and poly(2-(dimethylamino)ethyl methylacrylate)-b-poly(Nisopropylacrylamide) (PDMAEMA-b-PNIPAM) in aqueous solutions.The resultant complex micelles had a complex P4VP/ PDMAEMA/TPPS core and a mixed PEG/PNIPAM shell.Different noncovalent interaction modes between the porphyrin and each copolymer accomplished a co-effect on the aggregation of TPPS.The formation of aggregates was pH-dependent.At pH 3.2–6.5,TPPS existed as a mixture of H-aggregates and monomers because of the aromatic-aromatic interaction with P4VP and electrostatic interaction with PDMAEMA.The monomers translated into J-aggregates,stabilized by electrostatic interaction with the both polyelectrolyte blocks,upon decreasing the pH to 1.6.The free-base monomer was the one and only form for the dye at pH 11.0 due to aromatic stacking with the pyridyl rings.
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
