Advances for Triangular and Sandwich-Shaped All-Metal Aromatics

Area of Science:

• * Inorganic Chemistry
• * Theoretical Chemistry
• * Materials Science

Background:

• * Extensive research exists on all-metal aromaticity (σ, π, δ) in various metal types over the past two decades.
• * Previous work by Boldyrev, Schleyer, and Ugalde laid theoretical groundwork for metallo-clusters and aromaticity criteria like Nucleus-Independent Chemical Shifts (NICS).
• * Stable all-metal aromatic trinuclear clusters have been synthesized, serving as metallic analogs to organic aromatic ions.

Purpose of the Study:

• * To provide a comprehensive summary of triangular and sandwich-shaped all-metal aromatics.
• * To consolidate theoretical predictions, synthesis methods, and diverse applications of these unique compounds.
• * To address and counter the misconception that all-metal aromatics have limited applications due to synthesis and stability concerns.

Main Methods:

• * Review of theoretical predictions and computational studies on all-metal aromatic systems.
• * Analysis of experimental data on the synthesis and isolation of stable all-metal aromatic clusters.
• * Compilation of documented applications in coordination chemistry, catalysis, and material science.

Main Results:

• * Triangular all-metal aromatics conform to the Hückel (4n + 2) rule and can act as ligands for all-metal sandwiches.
• * These structures offer significant potential in coordination chemistry, catalysis, and material science, contrary to some prior opinions.
• * Despite challenges, stable triangular and sandwich-shaped all-metal aromatics have been synthesized and exhibit diverse applications.

Conclusions:

• * Triangular and sandwich-shaped all-metal aromatics are important and versatile chemical entities.
• * This review emphasizes their significance and broad applicability, encouraging further research and development.
• * The findings highlight the potential of these compounds in advancing chemical synthesis and material design.