Core engineering of paired core-shell silver nanoclusters

Unlike the facile modulation of surface structure through protecting ligands,the core shielded by outer shell of silver nanoclusters is still hard to be controlled.Ligand effects may seep into the incipient growth of silver core.However,the comparable cases to validate such hypothesis are currently lacking.Herein,we shed light on two core-shell silver nanoclusters,Ag_(7)S_(6)@Ag_(48)(SD/Ag55b,SD=SunDi)and Ag_(6)S_(6)@Ag_(48)(SD/Ag54b),differing in only one silver atom in the core which varies from a pentagon-bipyramidal Ag_(7)to an octahedral Ag_(6)while keeping the Ag_(48)shielding shell almost the same.Although no direct bonding between alkynes and silver core is observed in them,we propose that the ligand effect still exerts profound influences on the size and geometry of silver core.The solution behaviours and complete ligand-exchange reaction of SD/Ag55b in CH_(2)Cl_(2)are investigated using electrospray ionization mass spectrometry.Due to more and stronger argentophilic interactions,SD/Ag55b exhibits room-temperature phosphorescence with a 40 nm red-shift compared to that of SD/Ag54b in CH_(2)Cl_(2).This work not only presents effective fabrication of silver nanoclusters via synergism of dithiophosphate and alkyne ligands,but also provides us a pair of comparable examples to understand substitution group effect of protecting ligand on the core structures and properties.

In Situ Capture of a Ternary Supramolecular Cluster in a 58-Nuclei Silver Supertetrahedron

Although inorganic anion templates are highly appreciated in the synthesis of nanosized silver clusters,supramolecular clusters used as templates to mold silver nanoclusters remain as-yet-unknown due to their existence as volatile forms in solution.Here,we report the synthesis of a novel silver-thiolate nanocluster(SD/Ag58a),comprising an outer tetrahedral cage of 58 silver atoms and a central supramolecular cluster[CH_(3)OH@(SO_(4))_(4)(H_(2)O)6]8−(hereafter abbreviated as CS_(4)H_(6)).Ternary CS_(4)H_(6) cluster was constructed from an(SO_(4))_(4) tetrahedron encaging one CH_(3)OH molecule inside and six water molecules sitting between paired SO_(4)^(2−)ions to form the[SO_(4)…H_(2)O…SO_(4)]hydrogen bonds(H-bonds).Also,the CS4H6 could coordinate to the inner wall of the Ag58 cage by forming Ag-O bonds,exerting templating effect on the formation of SD/Ag58a.Moreover,SD/Ag58a showed a photocurrent response upon visible light irradiation and emitted luminescence in the near-infrared(NIR)region at a cryogenic temperature.This work exemplifies the ternary supramolecule templating effect in the construction of silver nanocluster and facilitates understanding of the structure of complex solvated anion cluster in atomic precision.