A highly active sulfur based pincer ruthenium catalyst for CO₂ hydrogenation

Area of Science:

• Organometallic Chemistry
• Catalysis
• Sustainable Chemistry

Background:

• Ruthenium catalysts are crucial for CO2 hydrogenation.
• Pincer ligands enhance catalyst stability and activity.
• Developing efficient and stable catalysts for CO2 utilization is a key challenge.

Purpose of the Study:

• To synthesize and characterize a novel air-stable sulfur-donor pincer ligand (SPS).
• To investigate the performance of a ruthenium catalyst supported by the SPS ligand for CO2 hydrogenation.
• To compare the catalytic activity with existing pincer-supported ruthenium systems.

Main Methods:

• Synthesis of the SPS pincer ligand.
• Complexation of the ligand with ruthenium.
• Catalytic testing for CO2 hydrogenation to formate.
• Catalytic testing for N-formylation of amines.

Main Results:

• A new air-stable SPS pincer ligand was successfully synthesized.
• The SPS-supported Ru catalyst demonstrated high activity for CO2 hydrogenation to formate.
• The catalyst exhibited higher activity than related PNP-supported Ru catalysts.
• Reduced dependence on Lewis acidic Li co-catalysts was observed for high turnover numbers.
• The Ru-SPS catalyst was also active for N-formylation of amines using CO2.

Conclusions:

• The novel SPS pincer ligand provides a robust platform for ruthenium catalysis.
• This sulfur-donor based system offers a promising alternative for efficient CO2 conversion.
• The catalyst's activity in both hydrogenation and N-formylation highlights its versatility.