Hydroxopalladium(IV) complexes prepared using oxygen or hydrogen peroxide as oxidants

Area of Science:

• Organometallic Chemistry
• Catalysis
• Coordination Chemistry

Background:

• Palladium complexes are vital in catalysis.
• Oxidation of palladium(II) to higher oxidation states is challenging.
• Understanding reaction mechanisms is crucial for catalyst design.

Purpose of the Study:

• To synthesize and characterize novel hydroxopalladium(IV) complexes.
• To investigate the reactivity and reaction mechanisms of these palladium(IV) complexes.
• To explore the potential for reductive elimination and C-O bond formation.

Main Methods:

• Synthesis of cyclometalated palladium(II) complexes.
• Oxidation with dioxygen or hydrogen peroxide.
• Structural characterization of palladium(IV) complexes.
• Reaction studies in different solvents (DMSO, chloroform).
• Density Functional Theory (DFT) calculations.

Main Results:

• Successful synthesis of rare hydroxopalladium(IV) complexes.
• Structural characterization confirms the stability of palladium(IV) species.
• Selective reductive elimination observed, forming C(sp2)-O bonds.
• Formation of pincer complexes and 2-t-butylphenol as major products.
• Mechanistic insights provided by DFT calculations.

Conclusions:

• Hydroxopalladium(IV) complexes can be accessed and are stable.
• These complexes offer a pathway for selective C-O bond formation via reductive elimination.
• The study provides valuable mechanistic understanding for palladium catalysis.