Intercluster exchanges leading to hydride-centered bimetallic clusters: a multi-NMR, X-ray crystallographic, and DFT...

Area of Science:

• Inorganic Chemistry
• Nanomaterials Science
• Supramolecular Chemistry

Background:

• Alloy nanoclusters are synthesized using intercluster reactions.
• Hydride-centered bimetallic clusters offer unique structural and electronic properties.

Purpose of the Study:

• To synthesize novel hydride-centered bimetallic clusters using intercluster reactions.
• To investigate the dynamic equilibrium and metal exchange processes in these clusters.

Main Methods:

• Synthesis of bimetallic clusters by mixing pre-formed monometallic clusters.
• Characterization using positive-mode ESI-MS, multi-NMR spectroscopy, and single crystal X-ray diffraction.
• Investigation of dynamic equilibrium via concentration-dependent 31P NMR and 2D exchange spectroscopy.
• Theoretical insights using Density Functional Theory (DFT) calculations.

Main Results:

• Successful synthesis of two series of hydride-centered bimetallic clusters: [Cu_xAg_7-x(H){E2P(OiPr)2}6] (E = S, 5; Se, 6).
• Structural determination of [Cu6Ag(H){S2P(OiPr)2}6] (5a) and [CuAg6(H){Se2P(OiPr)2}6] (6a) by X-ray diffraction.
• Evidence of a dynamic chemical equilibrium driven by metal exchanges, monitored by NMR spectroscopy.
• DFT calculations reveal preferential site occupancy: Silver in inner tetrahedral positions, copper in capping positions.

Conclusions:

• Intercluster reactions provide a viable route to synthesize complex bimetallic hydride clusters.
• The formation of these clusters is governed by a dynamic equilibrium of metal exchange.
• Computational and experimental data elucidate the structural preferences of copper and silver within the cluster framework.