Photo-active cobalt cubane model of an oxygen-evolving catalyst

Area of Science:

• Inorganic Chemistry
• Photochemistry
• Catalysis

Background:

• Oxygen-evolving catalysts (OECs) are crucial for artificial photosynthesis.
• Heterogeneous cobalt-based OECs show promise but require molecular understanding.
• Developing soluble molecular models aids in studying OEC mechanisms.

Purpose of the Study:

• To construct a soluble molecular model of a heterogeneous cobalt-based oxygen-evolving catalyst (Co-OEC).
• To investigate the interaction between cobalt-oxo cores and photosensitizers.
• To understand energy and electron transfer processes in Co-OEC-like systems.

Main Methods:

• Covalent attachment of a Re(I) photosensitizer to a cobalt-oxo cubane core.
• Characterization using X-ray diffraction for solid-state structure.
• Solution-state analysis using spectroscopic and electrochemical techniques.

Main Results:

• A soluble dyad complex, a molecular model of Co-OEC, was successfully synthesized.
• Characterization confirmed the covalent linkage between the Co(4)O(4) core and Re(I) moieties.
• Emission quenching of Re(I) photocentres was observed upon attachment to the cobalt-oxo core.

Conclusions:

• The constructed dyad complex serves as a valuable soluble model for heterogeneous Co-OEC.
• The observed emission quenching provides insights into energy and electron transduction pathways.
• This study advances the understanding of molecular mechanisms in cobalt-based water oxidation catalysis.