Self-Assembly-Driven Aggregation-Induced Emission of Silver Nanoclusters for Light Conversion and Temperature Sensing

Abstract

Supramolecular self-assembly is an effective method for constructing complex ordered aggregates with specific functions by noncovalent bonding. However, silver nanoclusters (NCs) have rarely been explored in the self-assembly of nanoscale building blocks, and the noncovalent forces (electrostatic, hydrogen-bonding, π−π-stacking interactions, etc.) and argentophilic interactions [Ag(I)•••Ag(I)] are crucial in directing to the supramolecular self-assembly of Ag(I) compounds. Here, we used silver NCs (Ag 9 -NCs, [Ag 9 (mba) 9 ], where H 2 mba = 2mercaptobenzoic acid) as the model cluster to interact with succinic acid (SA) to construct a nanofiber structure. The formation of highly ordered nanofibers is the result of SA-modified peripheral ligands of Ag 9 -NCs. Under the action of noncovalent forces (hydrogen-bonding, π−πstacking, and hydrophobic interactions), the reconstruction of this ordered structure not only increases the content of Ag(I) species in the protective shell of Ag 9 -NCs but also provides the possibility for directional argentophilic interactions [Ag(I)•••Ag(I)]. More interestingly, the compact structure and effective argentophilic interactions in the nanofibers synergistically achieve aggregation-induced emission, thereby inducing the emission of phosphorescence, which can be used as a temperature-controlled detector. Moreover, the orange-red Ag 9 -NCs/SA xerogels, together with commercial phosphor, can also be used as a phosphor to produce white-light-emitting-diode color conversion materials.

Construction and Humidity Response of a Room‐Temperature‐Phosphorescent Hybrid Xerogel Based on a Multicharge Supramolecular Assembly

“…The microscopy image showed a clear network structure that can be expected to have restricted vibrational and nonradiative relaxation of the PYCl phosphor. [ 22 ] Triplet luminescence is generally affected by water, which greatly reduces the intensity of RTP. Therefore, the xerogel showed green fluorescence–phosphorescence dual emission under 365 nm UV irradiation, whereas the hydrogel showed only blue fluorescence under these conditions.…”

Self‐Assembly of Precision Noble Metal Nanoclusters: Hierarchical Structural Complexity, Colloidal Superstructures, and Applications

“…reported the similar chemistry behind the argentophilic interactions in Ag NCs. [ 264 ] The interaction of water‐soluble [Ag 9 ( o ‐MBA) 9 ] NCs with succinic acid resulted in the conversion of NCs into well‐ordered phosphorescent hydrogels. The acid interaction helped to induce a topography reconstruction of NCs into Ag 1 species on the surface.…”

“…Furthermore, the self‐assembled (NH 4 ) 9 [Ag 9 ( p ‐MBA) 9 ] or (NH 4 ) 9 [Ag 9 ( o ‐MBA) 9 ] NCs were utilized to produce white‐light emission by incorporating commercially available phosphors. [ 224,264 ] The above‐discussed NC‐assemblies have been successfully used to fabricate the color conversion layers in LEDs.…”

Revisiting an ancient inorganic aggregation‐induced emission system: An enlightenment to clusteroluminescence

“…[ 9 ] ] Furthermore, some interesting phenomenons such as the aggregation‐induced emission (AIE, vide infra) property of inorganic clusters is difficult to explain by the traditional photophysical models. [ 11–17 ]…”