Bolaamphiphiles Bearing Bipyridine as Mesogenic Core: Rational Exploitation of Molecular Architectures for Controlled Self-Assembly

摘要

A bolaamphiphile (5,5-B2NBr8) bearing a functionalnbipyridine moiety as the mesogenic core is reported for the first time.n5,5-B2NBr8 was found to self-assemble into uniform fibrous structurenin aqueous solution, when the concentration was higher than cmc.nAnalogues of 5,5-B2NBr8 with structural differences in chain length,nheadgroup, mesogenic core, and substituted position were synthesized,nelucidating that small variances of the molecular structure couldnlead to dramatic changes of the resulting assemblies. For example,ncompound 4,4-B2NBr8 showed only spherical colloidal aggregatesnrather than fibers as 5,5-B2NBr8 did, while the only differencenbetween them was the position at which the alkyl chains were attached onto bipyridine. A probable model for the fibrousnstructure of 5,5-B2NBr8 was proposed. Moreover, exploiting the coordination capacity of bipyridine, assembly and disassemblynof 5,5-B2NBr8 could be reversibly controlled through the addition of EDTA and Cu(II), respectively.