| Abstract
| - Supramolecular chirality in the Langmuir−Schaefer (LS) films of two achiral amphiphilic Schiff bases,2-(2‘-benzimidazolyliminomethyl)-4-octadecyloxyphenol (BSC18) and 2-(2‘-benzthiazolyliminomethyl)-4-octadecyloxyphenol (TSC18), was investigated. Both of these amphiphiles could form LS films from thewater surface or coordinate with Ag(I) in the subphase to form Ag(I)-coordinated LS films. Although bothof these amphiphiles were achiral, TSC18 formed a chiral LS film from the water surface, while BSC18formed a chiral Ag(I)-coordinated LS film from the aqueous AgNO3 subphase. The supramolecular chiralityin these LS films was suggested to be due to a cooperative stereoregular π−π stacking of the functionalgroups together with the long alkyl chains in a helical sense. The relationship between the chirality ofthe LS films and the molecular structures of TSC18 and BSC18 as well as their H-bond or coordinationbehaviors was discussed. The Schiff base films showed a reversible color change upon exposure to HCl andNH3 gas alternatively; however, the supramolecular chirality was irreversible during these processes.
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