Efficient CO₂ fixation into cyclic carbonates catalyzed by NNO-scorpionate zinc complexes

Area of Science:

• Organometallic Chemistry
• Catalysis
• Green Chemistry

Background:

• Carbon dioxide (CO2) utilization is crucial for sustainable chemistry.
• Developing efficient catalysts for CO2 fixation remains a significant challenge.
• Scorpionate ligands offer versatile coordination environments for metal complexes.

Purpose of the Study:

• To synthesize novel chiral zwitterionic NNO-scorpionate zinc complexes.
• To evaluate their efficacy as bifunctional catalysts for CO2 fixation.
• To compare their catalytic performance against neutral and binuclear analogs.

Main Methods:

• Synthesis of chiral zwitterionic NNO-scorpionate mononuclear zinc alkyls via quaternization.
• Catalytic testing for the cycloaddition of CO2 to epoxides.
• Characterization of catalytic activity, substrate scope, and functional group tolerance.

Main Results:

• High yields of zwitterionic zinc complexes were achieved.
• The zwitterionic catalysts demonstrated superior activity in CO2 fixation compared to neutral and binuclear analogs.
• The catalyst system operated effectively under mild, solvent-free conditions with broad substrate scope.

Conclusions:

• Chiral zwitterionic NNO-scorpionate zinc complexes are effective bifunctional catalysts for CO2 conversion.
• These catalysts offer an improved and sustainable route for cyclic carbonate synthesis.
• The developed catalytic system holds promise for green chemistry applications.