Heavier Alkyne-Ni⁰ Complexes, [R₂E₂·Ni] (E = Sn, Pb), Exhibiting σ-Complex Character

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• Coordination Chemistry

Background:

• Alkyne-transition metal complexes are vital in synthesis and catalysis.
• Analogous complexes with heavier group 14 elements (like tin and lead) are scarce.
• Existing methods do not readily form these desired complexes.

Purpose of the Study:

• To synthesize and characterize the first nickel(0) complexes containing heavier group 14 elements (Sn and Pb).
• To explore novel synthetic pathways for accessing these rare organometallic species.
• To elucidate the bonding nature and structural characteristics of these new complexes.

Main Methods:

• Synthesis of novel nickel(0) complexes with specific bulky phosphine ligands (CyLE).
• Utilized a novel reductive group elimination pathway from Sn(II) and Pb(II) precursors.
• Characterization through X-ray crystallography and computational studies (DFT).

Main Results:

• Successfully synthesized and structurally characterized the first tin(I) and lead(I) complexes stabilized by nickel(0).
• Demonstrated a new synthetic route involving reductive elimination from Sn(II) and Pb(II) precursors coordinated to nickel.
• Identified the complexes as sigma-complexes of E(I) dimers with a transition metal center, revealing a new bonding mode.

Conclusions:

• Established a novel synthetic strategy for accessing elusive heavier group 14 element complexes.
• The characterized nickel(0) complexes represent a new class of organometallic compounds with a unique E-Ni bonding interaction.
• These findings expand the scope of coordination chemistry and offer potential for new catalytic applications.