Dimeric Copper(I) Complex with a Disulfonamide-Bridged Core

Area of Science:

• Coordination Chemistry
• Organometallic Chemistry
• Catalysis

Background:

• Sulfonamidato-bridged dicopper(I) complexes are rare.
• The ligand pyridine-2-yl-sulfonyl-quinolin-8-yl-amide (psq) has not been previously used to form such complexes.

Purpose of the Study:

• To synthesize and characterize a novel sulfonamidato-bridged dicopper(I) complex.
• To investigate the reactivity of the complex, including C-Cl bond activation and O2 activation.
• To explore the catalytic potential of the complex in phenol oxidation.

Main Methods:

• Synthesis and single crystal X-ray structure determination of the dicopper(I) complex.
• Reactivity studies in solution (chloroform, acetonitrile).
• Investigation of catalytic oxidation of phenol substrates using O2.

Main Results:

• The first sulfonamidato-bridged dicopper(I) complex, {Cu[κ⁴-(μ-κN:κN-psq)]}₂, with a rhombic Cu(I)₂N₂ core was synthesized.
• The complex activates C-Cl bonds in chloroform and is oxidized by air in acetonitrile.
• The complex facilitates O2 activation for the catalytic oxidation of 2,6-di-tert-butylphenol to a dione (100% yield) and stoichiometric oxidation of para-blocked phenols to ortho-hydroperoxides.

Conclusions:

• The novel dicopper(I)-psq complex exhibits unique reactivity, including C-Cl and O2 activation.
• The complex shows promise as a catalyst for selective oxidation of phenols.
• The reaction mechanism is dependent on the phenol substrate's properties, with acidic phenols acting as proton donors instead of H-atom donors.