Isolation of a Terminal Co(III)-Oxo Complex

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Catalysis

Background:

• Late transition metal oxo complexes are vital intermediates in many catalytic reactions.
• High d-electron count oxo complexes are reactive and difficult to study.
• Complexes with d-electron counts greater than 4 are exceptionally rare.

Purpose of the Study:

• To synthesize and characterize stable, high d-electron count late transition metal oxo complexes.
• To investigate the reactivity and bonding properties of these unusual complexes.
• To provide experimental evidence for the existence and stability of frequently invoked catalytic intermediates.

Main Methods:

• Synthesis of cobalt-oxo complexes using a tris(imidazol-2-ylidene)borate scaffold.
• Thorough characterization using a suite of physical techniques.
• Single crystal X-ray diffraction for structural determination.

Main Results:

• Isolation and characterization of two highly unusual Co(III)-oxo complexes with six d-electrons.
• Demonstration of O atom and H atom transfer reactivity.
• Evidence of strong metal-oxygen bonding and sufficient stability for characterization.

Conclusions:

• Terminal metal oxo complexes with six d-electrons can be stable and isolable.
• The findings support the existence of related, often unobserved, catalytic intermediates.
• This work advances the understanding of reactivity and bonding in late transition metal oxo complexes.