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Supramolecular Assemblies of a Series of 2‐Arylbenzimidazoles at the Air/Water Interface: In Situ Coordination, Surface Architecture and Supramolecular Chirality
Author(s) -
Guo Zongxia,
Yuan Jing,
Cui Yong,
Chang Fei,
Sun Wenhua,
Liu Minghua
Publication year - 2005
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200401246
Subject(s) - supramolecular chemistry , chirality (physics) , supramolecular chirality , interface (matter) , in situ , surface (topology) , materials science , nanotechnology , chemistry , molecule , geometry , physics , organic chemistry , mathematics , chiral symmetry breaking , quantum mechanics , nambu–jona lasinio model , quark , gibbs isotherm
The spreading behavior and supramolecular assemblies of some arylbenzimidazoles with 2‐substituted aromatic groups such as phenyl, naphthyl, anthryl and pyrenyl on water surface and the subphase containing AgNO 3 were investigated. It was observed that although these compounds lack long alkyl chains, they showed surface activity when spread from chloroform solution on water surface and formed the supramolecular assemblies. When AgNO 3 was present in the subphase, a coordination between the imidazole group of the compounds and Ag I occurred in situ in the spreading film, which was verified by the surface pressure/area (π– A ) isotherms and UV/Vis absorption spectra. Both the spreading films from water and the aqueous AgNO 3 subphase were transferred onto solid substrates and their surface morphologies as well as properties were characterized by AFM, UV/Vis absorption and CD spectra. Various surface morphologies such as nanoparticles, block domains and nanoutensils were observed depending on the substituted aromatic groups. Interestingly, although all of these compounds were achiral, supramolecular chirality was obtained for some of the arylbenzimidazole films assembled from either the water surface or the subphase containing AgNO 3 . It was revealed that chiral assemblies could be obtained from water surface for the benzimidazoles which have pyrenyl or α‐naphthyl groups. For benzimidazole derivative with anthryl group, chiral assemblies could be obtained when spreading on the aqueous AgNO 3 subphase. For the benzimidazoles with phenyl or β‐naphthyl groups, no chirality was obtained. It was suggested that both the overcrowded stacking of the aromatic groups and the cooperative arrangement of the molecules on water surface or aqueous AgNO 3 subphase play a crucial role in forming the chiral supramolecular assemblies.