Silver(I) Ion Induced Monolayer Formation of 2-Substituted Benzimidazoles at the Air/Water Interface

The monolayer formation of a series of 2-substituted benzimidazoles at the air/water interface was studied by the measurements of surface pressure-area isotherms. Concentrated silver(I) ion in the subphase can induce the monolayer formation of 2-alkylbenzimidazole derivatives (BzCn) with the alkyl chain equal to or greater than C5 although the derivatives cannot form monolayers on pure water surface except BzC17. Similar behavior of monolayer formation of 2-phenylbenzimidazole was also observed. The measurements of UV spectra and X-ray photoelectron spectroscopy analysis of the transferred films suggested that such monolayer formation was fulfilled through an in situ formation of a polymeric silver(I)−benzimidazole complex at the air/water interface.