Observation of a bcc-like framework in polyhydrido copper nanoclusters

Area of Science:

• Materials Science
• Nanotechnology
• Inorganic Chemistry

Background:

• Copper (Cu) typically exhibits a face-centered cubic (fcc) structure in bulk form.
• Ligand-stabilized copper nanoclusters (NCs) with precise atomic structures are a rapidly developing area of nanomaterials.
• Achieving non-fcc structures in copper NCs presents a significant synthetic and structural challenge.

Purpose of the Study:

• To synthesize and determine the total structures of novel 28-nuclearity polyhydrido copper nanoclusters.
• To investigate the structural motifs and compare them with known bulk copper structures.
• To explore the role of interstitial hydrides in influencing the nanocluster architecture.

Main Methods:

• Synthesis of six distinct 28-nuclearity polyhydrido copper nanoclusters using various ligands and counterions.
• Total structure determination via X-ray single crystal diffraction.
• Computational analysis using Density Functional Theory (DFT) to confirm hydride presence and location.

Main Results:

• Successfully synthesized and characterized six isostructural 28-nuclearity polyhydrido copper nanoclusters.
• The overall metal framework adopts a sandwich structure (Cu2@Cu16 core with two Cu5 fragments).
• A significant finding is the presence of a distorted body-centered cubic (bcc) arrangement within the Cu2@Cu16 core, a structure not previously observed in copper nanoclusters.

Conclusions:

• The study reports the first observation of a bcc framework in copper nanoclusters, deviating from the expected fcc structure.
• Interstitial hydrides are confirmed to play a crucial role in distorting the bcc framework.
• These findings hold significant implications for designing high-nuclearity copper hydride nanoclusters with non-fcc architectures.