Unusual core engineering on a copper hydride nanoball.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Polyhydrido copper clusters are of interest for their unique structures and potential applications.
• Controlling the core structure of metal clusters is crucial for tuning their properties.

Purpose of the Study:

• To synthesize and characterize a novel neutral polyhydrido copper cluster.
• To investigate the core engineering capabilities of the synthesized cluster, specifically its ability to reversibly change its core structure.
• To explore the relationship between the new cluster and previously reported copper clusters.

Main Methods:

• Synthesis of the neutral polyhydrido copper cluster [Cu27H15{S2CNtBu2}12] using dithiocarbamates, Cu(I) salts, and NaBH4.
• Single-crystal X-ray diffraction analysis to determine the core-shell structure.
• Chemical transformations to induce reversible transitions between different core structures.
• ESI mass spectrometry and DFT calculations to analyze cluster species and structures.

Main Results:

• A neutral polyhydrido copper cluster, [Cu27H15], with a Cu24 rhombicuboctahedral outer cage and a Cu3 triangular inner core was successfully synthesized.
• The cluster demonstrated the ability to reversibly transition between a Cu3 triangular core and an irregular Cu4 tetrahedral core, while maintaining the outer Cu24 shell.
• [Cu27H15] can be converted to [Cu28H15]+ by degradation or addition of Cu(I) ions, and the reverse transformation is achievable with reducing agents or formic acid.
• A dimeric species, [Cu56H30(S2CNtBu2)24]2+, was observed and computationally studied, suggesting a structure linking [Cu28H15]+ and [Cu27H15] clusters.

Conclusions:

• The synthesized [Cu27H15] cluster serves as an intermediate in the formation of the more stable [Cu28H15]+ nanoball.
• Demonstrated controllable core engineering in polyhydrido copper clusters with reversible transitions.
• The findings provide insights into the structural dynamics and interconversion of copper hydride clusters.