Co-assembly of Ag-29 Nanoclusters with Ru(bpy)(3)(2+) for Two-Photon Up-Conversion and Singlet Oxygen Generation

Cluster ensembles by supramolecular interactions are expected to be a class of promising materials possessinginteresting properties and attractive features. We herein presenta new functional and atomically precise supramolecular silvernanocluster, Na[Ru(bpy)3][Ag29(BDT)12(TPP)2] (Ag29Ru), bycoassembling the star cluster Na3[Ag29(BDT)12(TPP)4] (Ag29)with the classic photosensitizer Ru(bpy)3Cl2. Taking advantageof electrostatic interactions and intermolecular hydrogenbonding, Ru(bpy)32+was constrained by the void spaces of thelattice of [Ag29(BDT)12(TPP)2]3-clusters, which reduced thesymmetry of the original structure of [Ag29(BDT)12(TPP)4]3-with the shedding of TPP. Interestingly, Ag29Ru exhibits aprominent difference in the singlet oxygen generation undervisible light irradiation compared to results for pure Ag29. DFT calculations show that the greater singlet oxygen productioncapacity is driven by the narrowed HOMO-LUMO gap of the Ag29Ru coassembly of Ag29with Ru(bpy)32+. More interestingly,the resulting Ag29Ru exhibits a typical two-photon excited photoluminescence, which opens a new avenue to obtain metal cluster-assembled functional materials