A Silylene Stabilized by a σ-Donating Nickel(0) Fragment

Area of Science:

• Organometallic Chemistry
• Silicon Chemistry
• Coordination Chemistry

Background:

• Silylenes are silicon analogues of carbenes with diverse reactivity.
• Stabilized silylenes, particularly those with transition metal ligands, are of significant interest.
• Understanding the electronic interplay between silicon and metal centers is crucial for designing new catalysts and materials.

Purpose of the Study:

• To synthesize and characterize a novel donor-stabilized silylene complex featuring a Ni(0) ligand.
• To investigate the cooperative reactivity between the silicon and nickel centers.
• To explore the influence of ligand orientation on the electronic properties and reactivity of the silylene-metal complex.

Main Methods:

• Synthesis of a new donor-stabilized silylene complex (4).
• Characterization of the complex, including its structural and electronic properties.
• Computational calculations (e.g., DFT) to analyze the electronic structure and bonding.

Main Results:

• Successful synthesis of complex 4, a donor-stabilized silylene with a Ni(0) ligand.
• Complex 4 exhibits a pyramidalized and nucleophilic silicon(II) center.
• Computational studies revealed that a 90° rotation of the Si-Ni bond reverses the electronic roles of the silicon and nickel centers.

Conclusions:

• The synthesized silylene complex displays unique cooperative reactivity due to the interplay of Si and Ni centers.
• Ligand orientation critically dictates whether the nickel fragment acts as a Lewis acid or Lewis base towards the silylene.
• This work demonstrates an unprecedented Ni(0) →silylene complex formation through simple bond rotation, highlighting novel electronic switching capabilities.