A redox-active Mn(0) dicarbene metalloradical

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Redox Chemistry

Background:

• Metalloradicals are compounds containing a metal atom with an unpaired electron.
• Manganese complexes are of interest due to their diverse oxidation states and catalytic potential.
• N-heterocyclic carbenes (NHCs) are versatile ligands in organometallic chemistry.

Purpose of the Study:

• To synthesize and characterize a novel redox-active manganese(0) metalloradical.
• To investigate the influence of countercations and solvation on the redox properties of the manganese complex.
• To model the observed redox potentials using the Born equation.

Main Methods:

• Single crystal X-ray diffraction was used to determine the molecular structure of the synthesized complex.
• Cyclic voltammetry was employed to study the redox behavior of the manganese complex.
• The Born equation was utilized to model the solvation-dependent redox potentials.

Main Results:

• A rare redox-active Mn(0) metalloradical, [Mn(CO)₃(Ph₂B(NHC)₂)]^-, was successfully synthesized and characterized.
• The complex was isolated with various countercations: [K(2.2.2)crypt]⁺, [Na(2.2.2)crypt]⁺, and [Li(DME)(12-crown-4)]⁺.
• Solvation-dependent Mn^I/0 redox potentials were observed and successfully modeled using the Born equation.

Conclusions:

• The study reports a rare example of a redox-active Mn(0) metalloradical.
• The findings highlight the significant impact of solvation on the electrochemical properties of such complexes.
• The successful application of the Born equation provides a theoretical framework for understanding these solvation effects.