"Bottled" spiro-doubly aromatic trinuclear [Pd₂Ru]⁺ complexes.

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Transition metal complexes are crucial in catalysis and materials science.
• Exotic bonding networks in polynuclear metal clusters are of significant research interest.
• Understanding heterobimetallic systems offers new avenues for designing advanced materials.

Purpose of the Study:

• To synthesize and characterize novel heterobimetallic triangular clusters containing Ruthenium (Ru) and Palladium (Pd).
• To investigate the structural and bonding properties of these new [Pd2Ru]+ complexes.
• To explore the potential for delocalized metal-metal bonding in clusters of non-adjacent elements.

Main Methods:

• Synthesis of heterobimetallic triangular clusters.
• Single-crystal X-ray diffraction for structural determination.
• Density Functional Theory (DFT) calculations for bonding analysis.

Main Results:

• Successfully synthesized the first examples of trinuclear Ru-Pd heterobimetallic clusters, specifically [Pd2Ru]+.
• Observed analogies and differences compared to parent [Pd3]+ clusters.
• Identified 'bottled' double aromaticity (spiroaromaticity) due to Ru's participation in two aromatic systems.
• Revealed unprecedented orbital overlap between Ru d-orbitals and Pd d-orbitals.
• Demonstrated stable clusters with delocalized metal-metal bonding from non-adjacent elements.

Conclusions:

• The synthesis of [Pd2Ru]+ clusters opens new possibilities in organometallic chemistry.
• The findings highlight the potential for creating stable clusters with delocalized metal-metal bonds using diverse transition metals.
• This work expands the understanding of bonding in polynuclear metal complexes and aromaticity.