Co-crystallization of atomically precise metal nanoparticles driven by magic atomic and electronic shells.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30135426.
- Also identified by DOI 10.1038/s41467-018-05584-9 and PMC identifier 6105650.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
This paper reports co-crystallization of two atomically precise, different-size ligand-stabilized nanoclusters, a spherical (AuAg)<sub>267</sub>(SR)<sub>80</sub> and a smaller trigonal-prismatic (AuAg)<sub>45</sub>(SR)<sub>27</sub>(PPh<sub>3</sub>)<sub>6</sub> in 1:1 ratio, characterized fully by X-ray crystallographic analysis (SR = 2,4-SPhMe<sub>2</sub>). The larger cluster has a four concentric-shell icosahedral structure of Ag@M<sub>12</sub>@M<sub>42</sub>@M<sub>92</sub>@Ag<sub>120</sub>(SR)<sub>80</sub> (M = Au or Ag) with the inner-core M<sub>147</sub> icosahedron observed here for metal nanoparticles. The cluster has an open electron shell of 187 delocalized electrons, fully metallic, plasmonic behavior, and a zero HOMO-LUMO energy gap. The smaller cluster has an 18-electron shell closing, a notable HOMO-LUMO energy gap and a molecule-like optical spectrum. This is the first direct demonstration of the simultaneous presence of competing effects (closing of atom vs. electron shells) in nanocluster synthesis and growth, working together to form a co-crystal of different-sized clusters. This observation suggests a strategy that may be helpful in the design of other nanocluster systems via co-crystallization.