Lessons from isolable nickel(I) precursor complexes for small molecule activation.

Area of Science:

• Organometallic Chemistry
• Catalysis
• Inorganic Chemistry

Background:

• Small-molecule activation by transition metals is crucial for organic transformations.
• Low oxidation states and coordination numbers in metals enhance reactivity.
• Monovalent nickel (Ni(I)) species are potent one-electron reducing agents.

Purpose of the Study:

• To explore the activation of small molecules (N(2)O, O(2), S, Se, Te, P(4)) using stable dinuclear β-diketiminate nickel(I) precursors.
• To investigate the reductive activation of O(2) and its potential in oxidation processes.
• To synthesize and characterize novel heterobimetallic complexes and study their reactivity.

Main Methods:

• Synthesis of stable dinuclear β-diketiminate nickel(I) precursor complexes.
• Reaction of nickel(I) complexes with O(2), N(2)O, heavier chalcogens, and white phosphorus.
• Density functional theory (DFT) calculations for structural and electronic analysis.
• Characterization of resulting nickel complexes, including heterobimetallic species.

Main Results:

• Stable nickel(I) complexes successfully activated O(2), forming superoxonickel(II) intermediates and enabling oxidation reactions.
• Activation of heavier chalcogens yielded superchalcogenido and dichalcogenido complexes.
• White phosphorus (P(4)) coordinated to nickel(I) without reduction, offering new functionalization possibilities.
• First heterobimetallic complexes with [NiO(2)M] and [NiS(2)M] cores were synthesized and studied.

Conclusions:

• Stable nickel(I) complexes are effective in activating diverse small molecules.
• The developed nickel complexes serve as models for metalloenzymes and hold promise for new catalytic applications.
• Understanding structure-reactivity relationships in heterobimetallic systems advances catalyst design.