Induced chirality of supramolecular assemblies of some amphiphiles with β-cyclodextrin through the interaction at the air/water interface

4-(N-Stearoylamino)-2-amino-azobenzene (AzoNH2C18) and 4-(N-stearoylamino)-azobenzene (AzoC18) have been synthesized. The inclusion complex formation of AzoNH2C18 and β-cyclodextrin (β-CyD) at the air/water interface was investigated and compared to that of AzoC18. It has been found that both the amphiphiles can form stable monolayer films on water surface. When the amphiphiles were spread on the aqueous solution of β-CyD, AzoNH2C18 can form inclusion complexes with the β-CyD molecules at the interface while AzoC18 cannot. The inclusion complex formation was confirmed by the changes in the isotherms and the circular dichroism (CD) and Fourier transform infrared (FT-IR) spectra of the transferred LS films. Atomic force microscopy (AFM) observation found morphological changes in the course of complex formation. It was suggested that the additional amino group in the azobenzene ring plays an important role in forming the inclusion complex in situ at the air/water interface.

The interfacial assemblies of two amphiphiles, 4-(N-stearoylamino)-2-amino-azobenzene (AzoNH2C18) and 4-(N-stearoylamino)-azobenzene (AzoC18), with β-cyclodextrin were investigated at the air/water interface. It has been found that while AzoNH2C18 formed inclusion complexes with β-CD in situ, AzoC18 could not.Figure optionsDownload as PowerPoint slide