CS₂ Reductive Coupling to Acetylenedithiolate by a Dinuclear Ytterbium(II) Complex

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Materials Science

Background:

• Carbon disulfide (CS₂) activation is crucial for synthesizing novel compounds and forming carbon-carbon bonds.
• Dinuclear metal complexes offer unique reactivity profiles compared to their mononuclear counterparts.
• Understanding the reduction pathways of small molecules like CS₂ is key to developing new synthetic methodologies.

Purpose of the Study:

• To investigate the reactivity of a dinuclear ytterbium(II) complex with carbon disulfide.
• To characterize the reduction products of carbon disulfide mediated by the ytterbium complex.
• To elucidate the mechanism of CS₂ reduction and the formation of novel ligands.

Main Methods:

• Synthesis and isolation of a dinuclear ytterbium(II) complex [Yb₂ L₄], where L = (OtBu)₃SiO^-.
• Reaction of the ytterbium complex with carbon disulfide (CS₂).
• Crystallographic characterization of the resulting reduction products, including [Yb₂ L₄ (μ-C₂ S₂)].
• Computational studies to analyze the binding modes and reaction mechanisms.

Main Results:

• Isolation of unprecedented reduction products from the reaction of [Yb₂ L₄] with CS₂.
• Crystallographic determination of complex [Yb₂ L₄ (μ-C₂ S₂)], featuring the first example of an acetylenedithiolate ligand derived from CS₂ metal reduction.
• Computational analysis revealed an unusual binding mode of CS₂^2- in a key intermediate [Yb₂ L₄ (μ-CS₂)], attributed to the dinuclear nature of the ytterbium complex.

Conclusions:

• The dinuclear ytterbium(II) complex facilitates the reduction of carbon disulfide to form an acetylenedithiolate ligand.
• This reactivity highlights the potential of dinuclear complexes in small molecule activation and C-C bond formation.
• The findings provide fundamental insights into the coordination and reduction chemistry of CS₂ with early transition metals.