Amphiphilicity Regulation of AgI Nanoclusters: Self-Assembly and Its Application as a Luminescent Probe.

Research on the self-assembly of various amphiphilic molecules is a relatively new research area and of great significance. However, new kinds of metal-nanocluster (NC)-based amphiphilic molecule have rarely been explored. Herein, hydrophobic cation 1-hexadecyl-3-methylimidazolium (C16 mim+ ) was chosen to modify hydrophilic (NH4 )6 [Ag6 (mna)6 ] (Ag6 -NCs, H2 mna=2-mercaptonicotinic acid) and Ag6 @C16 mim-NCs were obtained. Ag6 @C16 mim-NCs displayed thermotropic liquid crystal and thermofluorescent properties. Moreover, the Ag6 @C16 mim-NCs exhibits benign amphiphilicity, and it can self-assemble into ordered nanosheets and nanorods through aggregation in water/dimethyl sulfoxide (DMSO) binary solvent mixtures, whereas single Ag6 -NCs do not. Meanwhile, the Ag6 @C16 mim-NCs also displays aggregation-induced emission properties owing to the restriction of intramolecular vibrations of the capping ligands. Furthermore, the luminescent aggregates could detect arginine selectively with the detection limit at 28 μm. This study introduces a new kind of metal-NC-based amphiphilic molecule in a supramolecular self-assembly field, and they have potential to be used as optical materials in applied research.