Triggering Electron Transfer in Co(I) Dimers: Computational Evidences for a Reversible Disproportionation Mechanism.

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Computational Chemistry

Background:

• Cobalt complexes are crucial in catalysis.
• Understanding disproportionation mechanisms is key to controlling reactivity.
• The role of ligands in stabilizing metal centers is vital.

Purpose of the Study:

• To elucidate the inner-sphere disproportionation mechanism of a Cobalt(I) precursor.
• To investigate the essential role of oleylamine in this process.
• To analyze the electronic structure of Cobalt dimers and their stabilization.

Main Methods:

• Density Functional Theory (DFT) calculations.
• Analysis of electronic structure of Cobalt dimers (Co2Cl2Ln).
• Investigation of ligand effects (amine and phosphine).

Main Results:

• An inner-sphere disproportionation mechanism for CoCl(PPh3)3 was described.
• Oleylamine was identified as essential for the disproportionation process.
• Asymmetric coordination of amine and phosphine ligands stabilizes a mixed-valence Co(II)-Co(0) dimer, facilitating electron transfer.

Conclusions:

• The study proposes a quasi-athermic, multi-step disproportionation mechanism.
• Low activation barriers were observed for the electron transfer process.
• Ligand exchange between cobalt centers drives the electron transfer, consistent with HSAB principles.