Supramolecular organization and heterochiral recognition in Langmuir monolayers of chiral azobenzene surfactants

We study the self-assembly of novel azobenzene-based chiral surfactants at the air/water interface, and find that while the pure enantiomers lack the ability to organize in ordered mesophases, the racemic mixture spontaneously forms a hexatic phase at low lateral pressures, which we detect by means...

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Detalles Bibliográficos
Autores: Pulido Companys, Alba, Albalat Piñol, Rosa, Garcia Amorós, Jaume, Velasco Castrillo, Dolores, Ignés i Mullol, Jordi
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2013
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/127909
Acceso en línea:https://hdl.handle.net/2445/127909
Access Level:acceso abierto
Palabra clave:Quiralitat
Agents tensioactius
Chirality
Surface active agents
Descripción
Sumario:We study the self-assembly of novel azobenzene-based chiral surfactants at the air/water interface, and find that while the pure enantiomers lack the ability to organize in ordered mesophases, the racemic mixture spontaneously forms a hexatic phase at low lateral pressures, which we detect by means of Brewster angle microscopy. This work provides a unique example of heterochiral recognition in which the racemic monolayer is not only condensed with respect to the pure enantiomers, but causes an ordered mesophase to form. Although hexatic order vanishes at high surface pressures, long-range orientational order is regained for all compositions upon monolayer collapse, which proceeds through the formation of birefringent trilayers with a well-defined lateral microstructure, as revealed by atomic force microscopy.