Partial Deoxygenative CO Homocoupling by a Diiron Complex.

Area of Science:

• Catalysis
• Organometallic Chemistry
• Climate Change Mitigation

Background:

• Converting carbon dioxide into carbon-neutral fuels is crucial for climate change mitigation.
• While CO conversion is established, coupling CO molecules to form C-C bonds for fuels remains difficult.

Purpose of the Study:

• To develop a novel catalytic method for the deoxygenative coupling of carbon monoxide (CO) molecules.
• To investigate the formation of C-C bonds from CO using a diiron complex.

Main Methods:

• Synthesis and characterization of a diiron complex with a bis(β-diketiminate) cyclophane ligand.
• Electrochemical reduction and silylation of the diiron complex.
• Spectroscopic analysis (Mössbauer, EPR) and Density Functional Theory (DFT) calculations.

Main Results:

• Successfully coupled two CO molecules using the diiron complex, forming a ketenylidene ligand (μ-CCO).
• Demonstrated C-OSiMe3 bond cleavage and subsequent C=C bond formation.
• Observed tunable magnetic exchange interactions and spin states of the diiron core.

Conclusions:

• The diiron complex facilitates the challenging deoxygenative coupling of CO molecules.
• This work provides a new route towards synthesizing C-C bonded products from CO, relevant for carbon-neutral fuel production.
• The study elucidates the electronic properties and magnetic behavior of the diiron system.