Multielectron oxidation in a ferromagnetically coupled dinickel(ii) triple mesocate

Area of Science:

• Coordination Chemistry
• Inorganic Chemistry
• Materials Science

Background:

• Meso-helicate complexes offer unique structural and electronic properties.
• Nickel complexes are vital in catalysis and materials science.
• Understanding multielectron redox processes is key to developing advanced materials.

Purpose of the Study:

• Synthesize and characterize novel triple-stranded dinuclear nickel(II) complexes.
• Investigate the multielectron redox behavior of these complexes.
• Explore the formation of high-valent nickel species.

Main Methods:

• Ligand synthesis: N,N'-1,3-phenylenebis(pyrazine-2-carboxamidate).
• Complex formation: Triple-stranded dinuclear nickel(II) meso-helicates.
• Electrochemical analysis: Cyclic voltammetry to study redox behavior.
• Computational chemistry: Density functional theory (DFT) for electronic structure and spin coupling.

Main Results:

• Successful synthesis of novel dinuclear nickel(II) meso-helicate complexes.
• Observation of up to four stepwise, one-electron oxidation events.
• Ferromagnetic coupling between the two Ni(II) ions was confirmed.
• Theoretical calculations supported the existence of dinickel(III) and dinickel(IV) species.

Conclusions:

• The synthesized nickel complexes display rich redox chemistry.
• The dinuclear nature and ferromagnetic coupling enable accessible high-valent states.
• These findings contribute to the understanding of multielectron transfer in polynuclear metal complexes.