A copper(I)-arene complex with an unsupported η6 interaction

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Computational Chemistry

Background:

• Copper-arene complexes are important in catalysis and materials science.
• Understanding ligand binding modes is crucial for designing new complexes.
• Previous copper-arene complexes typically involve different coordination modes.

Purpose of the Study:

• To synthesize and characterize novel copper-arene complexes.
• To investigate the binding mode of arene ligands to copper.
• To elucidate the factors governing the observed coordination geometry.

Main Methods:

• Synthesis of copper complexes with phosphine and hexamethylbenzene ligands.
• Spectroscopic characterization of the resulting complexes.
• Density Functional Theory (DFT) calculations to analyze bonding and energetics.

Main Results:

• Formation of the first copper-arene complexes featuring an unsupported η(6) arene interaction.
• Characterization of [(η(6)-Me6C6)Cu(PR3)][PF6] complexes, where R=Ph or OPh.
• DFT analysis confirmed the preference for the η(6) binding mode due to steric repulsion.

Conclusions:

• The steric clash between the arene's methyl groups and the phosphine's phenyl rings enforces the η(6) coordination.
• This study expands the known coordination chemistry of copper-arene systems.
• The findings provide insights into ligand design for controlling coordination modes in organometallic complexes.