Diphosphine-Protected IrAu₁₂ Superatom with Open Site(s): Synthesis and Programmed Stepwise Assembly.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Superatomic metal clusters offer unique electronic and optical properties.
• Controlling the surface chemistry of these clusters is crucial for their application.
• Iridium-gold clusters are promising building blocks for advanced materials.

Purpose of the Study:

• To selectively remove phenylacetylide ligands from [IrAu12(dppe)5(PA)2]+.
• To investigate the structural and electronic changes upon ligand removal.
• To explore the reactivity of the resulting open metal sites for further functionalization.

Main Methods:

• Controlled acid treatment to induce ligand removal.
• UV-Vis and Nuclear Magnetic Resonance (NMR) spectroscopy for structural and electronic characterization.
• Density Functional Theory (DFT) calculations to model the cluster structure and reactivity.

Main Results:

• Selective removal of one or two phenylacetylide (PA) ligands using tetrafluoroboric acid.
• Formation of open gold sites on the IrAu12 core in [IrAu12(dppe)5(PA)1]2+ and [IrAu12(dppe)5]3+.
• Successful trapping of isocyanide at the open site and formation of dimers/trimers with diisocyanide linkers.

Conclusions:

• Demonstrated a method for controlled de-ligandization of IrAu12 superatoms.
• Revealed the formation of reactive electrophilic sites on the cluster surface.
• Opened pathways for the designed assembly and chemical modification of metal superatoms for potential applications.