Transition-Metal Complexes Featuring Dianionic Heavy Group 14 Element Aromatic Ligands.

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• Aromaticity Studies

Background:

• Ferrocene and its analogues, based on cyclopentadienyl (Cp) ligands, are crucial in various chemical fields.
• Modifications of Cp ligands aim to tune the electronic and structural properties of sandwich complexes.
• Introducing heavy Group 14 elements into π-skeletons was explored to understand their impact on aromaticity and complex formation.

Purpose of the Study:

• To synthesize and characterize dilithio-stannoles and -plumboles, dianionic aromatic compounds containing tin and lead.
• To investigate the application of these heavy analogues as ligands for transition-metal complexes.
• To explore the resulting complexes' electronic structures and properties, comparing them to traditional Cp-based systems.

Main Methods:

• Synthesis of dilithio-stannoles and -plumboles.
• Complexation reactions with transition metals (e.g., Ruthenium, Group 4 metals).
• Structural and electronic characterization of the resulting organometallic complexes.

Main Results:

• Successful synthesis of aromatic dilithio-stannoles and -plumboles, demonstrating expanded aromaticity concepts.
• Formation of novel neutral triple-decker and anionic ruthenocene complexes using stannole ligands.
• Anionic ruthenocenes with plumbole ligands showed lower oxidation potentials than tin analogues, highlighting the effect of heavier atoms.

Conclusions:

• Dilithio-stannoles and -plumboles serve as effective ligands, enabling the creation of transition-metal complexes with unique electronic structures.
• The incorporation of heavy Group 14 atoms into π-skeletons significantly perturbs the properties of conventional transition-metal complexes.
• This work opens new avenues in organometallic chemistry by utilizing heavy Group 14 elements in π-ligand design.