Controlled cluster expansion at a Zintl cluster surface.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Cluster Chemistry

Background:

• Zintl cluster salts, specifically K[Ge9(Hyp)3] (Hyp=Si(SiMe3)3), are versatile precursors in inorganic synthesis.
• Metal-catalyzed cluster core expansion is a key strategy for generating complex multinuclear structures.

Purpose of the Study:

• To synthesize novel eleven- and twelve-vertex homo- and hetero-multimetallic clusters.
• To expand the methodology for creating Zintl clusters with diverse metal compositions.
• To elucidate the formation mechanism of these novel cluster compounds.

Main Methods:

• Reaction of K[Ge9(Hyp)3] with rhodium precursors like [Rh(COD)Cl]2.
• Stepwise synthesis involving Zintl clusters and iridium precursors like [Ir(COD)Cl]2.
• Density functional theory (DFT) calculations to investigate reaction mechanisms.

Main Results:

• Successful synthesis of eleven- and twelve-vertex homo-multimetallic clusters via cluster core expansion.
• Development of a stepwise procedure to create eleven-vertex hetero-multimetallic clusters.
• Proposed mechanism for the formation of the first closo eleven-vertex Zintl clusters.

Conclusions:

• The reaction of K[Ge9(Hyp)3] with rhodium complexes enables cluster core expansion to form larger Zintl clusters.
• A stepwise approach allows for the controlled synthesis of hetero-multimetallic Zintl clusters.
• DFT calculations provide insights into the mechanistic pathways governing Zintl cluster formation and expansion.