Nitrous oxide activation by picoline-derived Ni-CNP hydrides

Area of Science:

• Organometallic Chemistry
• Catalysis
• Green Chemistry

Background:

• Nitrous oxide (N2O) is a potent greenhouse gas and a challenging substrate in catalysis.
• Nickel complexes offer tunable electronic and steric properties for catalytic applications.
• Proton-responsive ligands can modulate the reactivity of metal centers.

Purpose of the Study:

• To investigate the mechanism of oxygen atom transfer (OAT) from N2O to a Ni-H bond.
• To explore the catalytic activity of proton-responsive picoline-derived pincer (CNP) nickel complexes in N2O reduction.
• To understand the role of the Ni-CNP framework in facilitating N2O transformation.

Main Methods:

• Experimental studies involving kinetic measurements and product analysis.
• Theoretical investigations using density functional theory (DFT) calculations.
• Synthesis and characterization of novel nickel-pincer complexes.

Main Results:

• Demonstrated efficient oxygen atom transfer from N2O to the Ni-H bond.
• Identified Ni-CNP complexes as effective catalysts for N2O reduction with pinacolborane (HBpin).
• Elucidated the reaction pathway, highlighting the crucial role of the nickel hydride intermediate.

Conclusions:

• Proton-responsive CNP nickel complexes are highly effective catalysts for N2O reduction.
• The OAT mechanism provides a viable pathway for N2O valorization.
• This catalytic system operates under mild conditions, offering a greener approach to N2O management.