Hexanuclear 3d-4f complexes as efficient catalysts for converting CO₂ into cyclic carbonates.

Area of Science:

• Coordination Chemistry
• Catalysis
• Green Chemistry

Background:

• Cyclic carbonates are valuable chemical intermediates.
• Efficient catalytic methods are needed for CO2 utilization.
• 3d-4f metal complexes offer unique electronic and magnetic properties.

Purpose of the Study:

• Synthesize and characterize novel hexanuclear 3d-4f complexes.
• Evaluate their catalytic activity in the cycloaddition of CO2 and epoxides.
• Investigate the recyclability and efficiency of the catalytic system.

Main Methods:

• Solvothermal synthesis of hexanuclear complexes.
• Characterization using elemental analysis, IR, UV-Vis, and magnetic susceptibility.
• Catalytic testing for CO2 cycloaddition with various epoxides.
• Recycling experiments to assess catalyst reusability.

Main Results:

• Successfully synthesized and characterized three hexanuclear 3d-4f complexes (Dy, Nd, Tb).
• Exhibited excellent catalytic performance for CO2 cycloaddition, yielding cyclic carbonates.
• Achieved high turnover numbers (9700) and turnover frequencies (808 h-1) under mild conditions.
• Demonstrated catalyst recyclability without significant loss of activity.

Conclusions:

• The novel hexanuclear 3d-4f complexes are effective catalysts for CO2 cycloaddition.
• This catalytic system provides a sustainable route for cyclic carbonate synthesis.
• The catalysts are scalable, recyclable, and operate under mild conditions, aligning with green chemistry principles.