An Atomically Precise Alkynyl-Protected PtAg₄₂ Superatom Nanocluster and Its Structural Implications

Area of Science:

• * Inorganic Chemistry
• * Materials Science
• * Nanotechnology

Background:

• * Superatom nanoclusters (SNCs) exhibit unique properties due to their electronic shell structure.
• * The synthesis and structural elucidation of complex, multi-metal SNCs remain a significant challenge.
• * Understanding the protective ligands and their interaction with the cluster core is crucial for stability and functionality.

Purpose of the Study:

• * To synthesize and determine the crystal structure of a novel Pt-doped Ag superatom nanocluster.
• * To investigate the structural arrangement of the metallic core and the surface ligands.
• * To explore the unprecedented protective role of SbF6- anions in SNCs.

Main Methods:

• * Single-crystal X-ray diffraction for precise structure determination.
• * Synthesis of the alkynyl-protected Pt-doped Ag superatom nanocluster.
• * Spectroscopic and analytical techniques for characterization.

Main Results:

• * Successful synthesis and structure determination of [PtAg42(C≡CC6H4CH3)28](SbF6)6 (1).
• * Discovery of a concentric three-shell Pt@Ag12@Ag30 core, including a previously missing icosidodecahedral Ag30 shell and a novel M43 unit.
• * Identification of co-protection by alkynyl ligands and SbF6- anions, with SbF6- exhibiting an unprecedented protective role.
• * Observation of unique alkynyl ligand connectivity through pentagonal faces to both inner and outer silver shells.

Conclusions:

• * The crystal structure determination of nanocluster 1 reveals the missing Ag30 shell and a novel M43 structural unit.
• * SbF6- anions play an unprecedented protective role in stabilizing the nanocluster.
• * The study demonstrates unique ligand penetrability through pentagonal faces, offering new insights into SNC design and stabilization.