Reactivity of copper(II)-alkylperoxo complexes

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Catalysis

Background:

• Copper complexes with amine ligands are crucial in various catalytic processes.
• Understanding the reactivity of copper-peroxo species is key to designing efficient oxidation catalysts.

Purpose of the Study:

• To synthesize and characterize novel copper(II) cumylperoxo complexes.
• To investigate the structural and mechanistic aspects of their decomposition and reactions.

Main Methods:

• Synthesis of copper(II) complexes with bis(2-pyridylmethyl)amine (bpa) and tris(2-pyridylmethyl)amine (tpa) ligands.
• Reaction with cumene hydroperoxide (CmOOH) to form copper(II) cumylperoxo complexes.
• Characterization using resonance Raman, ESI-MS, UV-vis, ESR spectroscopy, and DFT calculations.
• Product analysis of decomposition and reaction with 1,4-cyclohexadiene (CHD).

Main Results:

• Formation of copper(II) cumylperoxo complexes 2a and 2b confirmed by spectroscopic and mass spectrometric methods.
• Complex 2a exhibits temperature-dependent structural changes (5-coordinate square-pyramidal to 4-coordinate square-planar).
• Complex 2b adopts a trigonal bipyramidal structure.
• Complexes decompose via O-O bond homolytic cleavage, with partial hydrogen-atom abstraction from the solvent.
• Reaction with CHD involves concerted O-O bond homolytic cleavage and C-H activation by the proximal oxygen atom.

Conclusions:

• Novel copper(II) cumylperoxo complexes with tunable structures were successfully synthesized.
• The decomposition pathway involves homolytic O-O bond cleavage.
• The complexes demonstrate catalytic potential in C-H activation reactions, particularly with 1,4-cyclohexadiene.