Gold-Manganese Bimetallic Redox Coupling with Light

Area of Science:

• Organometallic Chemistry
• Photocatalysis
• Redox Chemistry

Background:

• Classical gold(I)/gold(III) redox chemistry is primarily used for C-C and C-X bond formation.
• Exploring elementary reactions in gold redox coupling is crucial for expanding its organometallic applications.

Purpose of the Study:

• To report the first visible-light-mediated, external oxidant-free gold(I)/gold(III) redox couple.
• To develop a robust strategy for constructing diverse gold-manganese complexes.
• To investigate the catalytic applications of the synthesized gold-manganese complexes.

Main Methods:

• Visible-light irradiation
• Use of dimanganese decacarbonyl (Mn2(CO)10) as a precursor
• Synthesis of heterodinuclear and polynuclear gold-manganese complexes
• Mechanistic studies including DFT calculations
• Catalytic reductive coupling of nitroarenes

Main Results:

• Successful generation of Mn-Au(III)-Mn intermediates for bimetallic redox coupling.
• Construction of 19 structurally diverse heterodinuclear and polynuclear L-Au(I)-Mn-L' complexes with high yields (>99%).
• Elucidation of radical oxidative addition and bimetallic reductive elimination mechanisms.
• Demonstration of catalytic activity in the reductive coupling of nitroarenes to azoxybenzenes, azobenzenes, and hydrazobenzenes.

Conclusions:

• The developed method provides a mild and efficient route to novel gold-manganese complexes.
• The study advances the understanding of elementary reactions in gold chemistry.
• The synthesized complexes show potential for catalytic applications in organic synthesis.