A Paramagnetic Nickel-Zinc Hydride Complex

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Catalysis

Background:

• Zinc-hydride compounds are valuable synthetic intermediates.
• Nickel complexes are widely used in catalysis.
• Understanding metal-metal hydride interactions is crucial for catalytic mechanisms.

Purpose of the Study:

• To synthesize and characterize a novel nickel-zinc hydride complex.
• To investigate the reactivity and catalytic potential of zinc-hydride bonds mediated by nickel.
• To elucidate the nature of the Ni-H-Zn interaction.

Main Methods:

• Reaction of a molecular zinc-hydride with a nickel precursor.
• Single crystal X-ray diffraction for solid-state structural analysis.
• Density Functional Theory (DFT) calculations for electronic structure.
• Electron Paramagnetic Resonance (EPR) spectroscopy for solution behavior.

Main Results:

• Isolation and characterization of a nickel-zinc hydride complex with a bridging 3-center, 2-electron Ni-H-Zn bond.
• DFT calculations support a sigma-complex formulation involving a nickel(I) fragment.
• EPR studies indicate lability in solution.
• Demonstration of H/D exchange and dehydrocoupling of zinc-hydride bonds catalyzed by nickel(I).

Conclusions:

• The study successfully synthesized and characterized a unique nickel-zinc hydride complex.
• The findings highlight the ability of nickel(I) centers to activate zinc-hydride bonds.
• This work provides insights into nickel-catalyzed functionalization of zinc-hydride bonds.