Ruthenium Complexes of Polyfluorocarbon Substituted Terpyridine and Mesoionic Carbene Ligands: An Interplay in CO₂...

Area of Science:

• Coordination Chemistry
• Catalysis
• Electrochemistry
• Materials Science

Background:

• Terpyridines (tpy) and mesoionic carbenes (MIC) are established ligands in metal complex catalysis.
• Both tpy and MIC ligands, when coordinated to a metal center, are individually known to be effective catalysts for CO2 reduction.
• Combining different ligand types within a single complex platform can lead to synergistic effects and enhanced catalytic performance.

Purpose of the Study:

• To synthesize and characterize novel metal complexes incorporating both polyfluorocarbon (PFC)-substituted tpy and MIC ligands.
• To investigate the structural, electrochemical, and spectroelectrochemical properties of these new complexes.
• To evaluate the potential of these complexes as electrocatalysts for CO2 reduction.

Main Methods:

• Synthesis of novel metal complexes featuring PFC-substituted tpy and MIC ligands.
• Structural characterization using X-ray diffraction and other spectroscopic techniques.
• Electrochemical studies including cyclic voltammetry.
• UV/Vis/NIR spectroelectrochemical analysis.
• Electrocatalytic testing for CO2 reduction.
• Preliminary mechanistic investigations and intermediate isolation.

Main Results:

• Successful synthesis and characterization of a new class of metal complexes integrating PFC-substituted tpy and MIC ligands.
• Detailed investigation of their structural, electrochemical, and spectroelectrochemical properties.
• Demonstration of potent electrocatalytic activity for CO2 reduction, exclusively yielding CO.
• Achieved a high faradaic efficiency of 92% for CO production.
• Isolation and characterization of a key intermediate, providing insights into the catalytic mechanism.

Conclusions:

• The combined tpy-MIC ligand platform, particularly with PFC substitution, offers a promising strategy for designing efficient CO2 reduction electrocatalysts.
• These novel complexes exhibit excellent selectivity for CO production with high efficiency.
• The mechanistic insights gained from intermediate characterization contribute to understanding CO2 reduction pathways.