Interfacial films of cyclic polyguanamine derivatives for metal capturing: Selectivity and fluorescence emission properties

We demonstrated that the interfacial films of a cyclic moiety-containing polyguanamine derivative have selectivity for metal capturing. In addition, the selectivity of the fluorescence emission depending on the captured metal ion species was determined. The metal capturing of the polyguanamine Langmuir monolayer demonstrated high selectivity for the metal cations present in the subphase depending on the ionic radius and valence. Therefore, it was confirmed that metal cations with a small ionic radius and large valence tended to be preferentially captured. This is consistent with typical metal desorption behavior, and cations that are more difficult to desorb are preferentially captured. In addition, the tilt angle of the cup-shaped conformation at the annular site correlated with the metal capturing selectivity. Furthermore, the emission and quenching of the fluorescence changed significantly depending on the captured metal ion species. [Display omitted] •Metal ions were collected in the organized films of the polyguanamine derivative.•Only one was selectively collected from the subphase containing multiple metal ions.•There was correlation between selectivity of collected metal and desorption behavior.•Polyguanamine film showed fluorescence emission by collection of specific metal ions.•Fluorescence emission was associated with conformational transition of cyclic part.