Luminescent iron clusters in solution.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Atomically precise metal clusters exhibit unique properties and potential applications.
• Synthesis of analogous systems using reactive metals like iron in solution remains challenging due to high reactivity.
• Noble metal clusters have been synthesized, but reactive metal clusters are less explored.

Purpose of the Study:

• To report the synthesis and characterization of novel iron clusters in a solution phase.
• To overcome the challenge of high reactivity of iron for cluster synthesis.
• To explore the properties of these novel iron clusters, such as luminescence and magnetism.

Main Methods:

• Synthesis of iron clusters within a hemoglobin matrix.
• Ligand exchange to remove the protein.
• Phase transfer from aqueous to organic solvent using tri-octylphosphineoxide (TOPO).
• Characterization using mass spectrometry.

Main Results:

• Successfully synthesized highly luminescent iron clusters (quantum yield 10% at 565 nm).
• Identified specific cluster compositions: [Fe₁₀(TOPO)₃(H₂O)₃](+), [Fe₁₃(TOPO)₂(H₂O)](+), and [Fe₈(TOPO)(H₂O)₂](+).
• Demonstrated super-paramagnetic properties of the synthesized iron clusters.
• Achieved phase transfer of clusters from water to chloroform.

Conclusions:

• This study presents the first realization of soluble, atomically precise iron clusters.
• The developed method enables the synthesis and stabilization of reactive metal clusters.
• These findings lay the groundwork for exploiting the unique properties of soluble iron clusters in various applications.