Structural Features of [(CpPPh2AuCl)2ZrCl2]: exploring the limits of aurophilic interactions

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Computational Chemistry

Background:

• Metallocene complexes, such as zirconocenes, are versatile precursors in organometallic chemistry.
• Gold complexes are increasingly studied for their unique electronic properties and potential applications.

Purpose of the Study:

• To synthesize and characterize a novel trimetallic complex involving a zirconocene and gold chloride.
• To investigate the structural and electronic properties of the resulting complex, particularly the presence or absence of aurophilic interactions.

Main Methods:

• Synthesis of the trimetallic complex [(CpPPh(2)AuCl)(2)ZrCl(2)] from [(CpPPh(2))(2)ZrCl(2)] and (Me(2)S)AuCl.
• X-ray crystallography to determine the solid-state structure of the complex.
• Quantum-chemical calculations to rationalize the observed structural features and bonding.

Main Results:

• The formation of the trimetallic complex [(CpPPh(2)AuCl)(2)ZrCl(2)] was confirmed.
• Crystallographic analysis revealed a specific conformation with P--Au--Cl vectors directed towards the open face of the bent metallocene.
• Computational studies indicated that noncovalent forces effectively counteract any potential attractive gold-gold (aurophilic) interactions.

Conclusions:

• A novel trimetallic zirconocene-gold complex was successfully synthesized and characterized.
• The complex adopts a conformation that prevents direct gold-gold bonding.
• Noncovalent interactions play a crucial role in dictating the electronic structure and stability of such multinuclear gold complexes.