[Ag67(SPhMe2)32(PPh3)8]3+: Synthesis, Total Structure, and Optical Properties of a Large Box-Shaped Silver Nanocluster
AuthorsAlhilaly, Mohammad J.
Bootharaju, Megalamane Siddaramappa
Joshi, Chakra Prasad
Besong, Tabot M.D.
Emwas, Abdul-Hamid M.
KAUST DepartmentAdvanced Membranes and Porous Materials Research Center
Physical Sciences and Engineering (PSE) Division
Imaging and Characterization Core Lab
Functional Materials Design, Discovery and Development (FMD3)
Permanent link to this recordhttp://hdl.handle.net/10754/622496
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AbstractEngineering the surface ligands of metal nanoparticles is critical in designing unique arrangements of metal atoms. Here, we report the synthesis and total structure determination of a large box-shaped Ag-67 nanocluster (NC) protected by a mixed shell of thiolate (2,4-dimethylbenzenethiolate, SPhMe2) and phosphine (triphenylphosphine, PPh3) ligands. Single crystal X-ray diffraction (SCXRD) and electrospray ionization mass spectrometry (ESI-MS) revealed the cluster formula to be [Ag-67(SPhMe2)(32)(PPh3)(8)](3+). The crystal structure shows an Ag-23 metal core covered by a layer of Ag44S32P8 arranged in the shape of a box. The Ag-13, core was formed through an unprecedented centered cuboctahedron, i.e., Ag-13, unlike the common centered Ag-13 icosahedron geometry. Two types of ligand motifs, eight AgS3P and eight bridging thiols, were found to stabilize the whole cluster. The optical spectrum of this NC displayed highly structured multiple absorption peaks. The electronic structure and optical spectrum of Ag-67 were computed using time-dependent density functional theory (TDDFT) for both the full cluster [Ag-67(SPhMe2)(32)(PPh3)(8)](3+) and a reduced model [Ag-67(SH)(32)(PH3)(8)](3+). The lowest metal-to-metal transitions in the range 500-800 nm could be explained by considering the reduced model that shows almost identical electronic states to 32 free electrons in a jellium box. The successful synthesis of the large box-shaped Ag-67 NC facilitated by the combined use of phosphine and thiol paves the way for synthesizing other metal clusters with unprecedented shapes by judicious choice of thiols and phosphines.
CitationAlhilaly MJ, Bootharaju MS, Joshi CP, Besong TM, Emwas A-H, et al. (2016) [Ag67(SPhMe2)32(PPh3)8]3+: Synthesis, Total Structure, and Optical Properties of a Large Box-Shaped Silver Nanocluster. Journal of the American Chemical Society 138: 14727–14732. Available: http://dx.doi.org/10.1021/jacs.6b09007.
SponsorsThe financial support for this work was provided by KAUST. The theoretical work was supported by the Academy of Finland. The computational resources were provided by CSC in Espoo, Finland.
PublisherAmerican Chemical Society (ACS)